This is a god-awful long, and most likely boring story. Once again I'm hoping I can serve as an example to all you fine readers, for what not to do.
About two weeks ago I pulled the Z3 into the garage and plugged it in. When I flipped on the charger I heard, what sounded like, a popping noise coming from the front of the car. It sounded like the noise you hear when you plug a speakers into the audio port on your computer, deep and quick. But there were some kids playing out front and I wasn't sure exactly where the noise came from. But the charger continued to charge and everything on the car checked out.
The following day I went to plug it in after another day's driving and I listened closely, this time with the garage door closed and the hood up. Sure enough, I heard the same pop, only this time the charger turned itself off. You may remember about a year and half ago, I was measuring one of the batteries during a charging cycle when one of the probes slipped and made contact with the chassis and the terminal at the same time. There was a pop, the end of my probe was vaporized, the charger shut off and the breaker for the 240 volt AC outlet tripped. That little mistake cost me $150 because I had to send the charger back to Manzanita to repair the AC rectifier which I blew up in the process.
After this recent pop I figured 1. I must have a high voltage leak to ground and 2. I'm going to have to send my charger along with another $150 to Manzanita. I decided to check for the leak and got out my multimeter. Sure enough, if I measured at the most positive terminal on the battery pack, and the chassis, I could measure the full 160 volts of the pack. Damn! I went to the fourth battery from the end of the pack and measured there and got the expected 13.2 volts. I wondered how much current could get through this leak, so I clipped a regular automotive tail light bulb to the positive terminal of that battery and the chassis and it glowed nice and bright. If there were no leak, or no path for current, that bulb would not light up.
OK, it was time to start disconnecting things to isolate where the leak was. This should be a pretty straight forward task, and it seemed to be at first, but it wasn't long before it got weird. I'll explain. I started by unhooking all the peripherals, one by one, using the multimeter after each to see if I had voltage to ground. I disconnected the DC to DC converter, the charger, the Masterflux A/C system, the ceramic heating element and finally the Link-Pro meter. By this time only thing hooked to the high voltage system where the Zilla controller, the motor and the batteries them selves, but still the leak was present. I unhooked the cables leading from the Zilla to the motor and the leak was gone. Ah ha, found it!
My guess was that through poor design, I'd placed a cable close to something sharp and it had rubbed through and shorted to the chassis. In deed, I found what looked like a suspicious wear mark on top of one of the rubber boots, under which is one of the terminals of the motor. But as it happened, it had not worn through, though it would have eventually. But then I noticed that I'd done something else that was remarkably stupid. The main high voltage fuse of the car, which is held in a special holder which does not keep the fuse from sort of sliding one direction or another, had migrated one direction and looked like it was touching a part of the chassis. Well, there you go!!!
I fixed that problem and insulated the connection so that it can creep all it wants and will never short against anything again. I checked all the other cables and connections and found them good, so I started putting everything together. I got everything back together, put the multimeter on the car and... I could still read the pack voltage. Ah crap! But this time, there was an important difference. When I performed the light bulb test, there was not enough current flowing through the chassis to make the bulb light up. At this point, I'm thinking there must have been two leaks. I'm assuming I fixed the more serious one, but there's still a smaller one.
Now's where things get strange. I started testing again, trying to be as methodical as possible, but I kept getting strange results, or results I didn't expect and couldn't explain. For a while I was certain there was a leak through the Zilla, but that wasn't the case. You see the problem is that I've run up to the end of my knowledge at this point. When it comes to electrical stuff and electronics, if I can't SEE it, I'm probably not going to understand it. I can SEE a wire touching the frame. But once that wire enters a device, as far as I'm concerned what goes on in there is simply magic.
I'll save you some of the wretched details, but suffice it to say after disconnecting everything one at a time, again, I was left with only the batteries connected to the Zilla and I still had a leak. But then I saw that I still had the current sensing leads from the Link-Pro connected to the shunt. I thought well that can't be the problem, but I'll disconnect them to be sure. Lo and behold, the leak went away. What the hell!! Maybe that line got pinched or abraded. Nope, it looked fine. The meter is supposed to be completely isolated from the chassis because I've used an isolating DC to DC converter specifically to power the meter. I measured the 12 V output of that DC to DC converter and found that I could read 12 Volts if I grounded to the chassis. Well that's not supposed to happen! There's my problem!! Or so I thought.
I started putting everything back together, one thing at a time, taking measurements with each connection made. For kicks I connected the Link-Pro's shunt lines, expecting to see the leak and it wasn't there. Ah, for crying out loud! In fact, I measured the output of the Link-Pro's DC to DC converter power supply and it now no longer has any connection to ground. Still scratching my head, wondering what the hell is going on, I connect the motor back up and the leak reappears. Right about now, I'm prepared to burn the car to the ground and walk away.
Ignoring the Link-Pro issues for now, I focus on the motor. I took the Zilla out of the loop and had simply a small pack of 12 cells and the motor ready for testing. I hooked the negative line from the battery to the negative input of the motor, which happens to be labeled 'A1'. Then I put the multimeter on the positive end of the battery and the car's chassis and I could read the battery's voltage. That means there is a path for current from the battery, through the motor, into the chassis and back to the battery. I measured the resistance and found that it was 1.19K ohms. Now that's not much, and if I plug that into an Ohm's law calculator taking into account the full 160V pack voltage, that means that leak can pass only 0.135 amps, or 135 milliamps.
I don't think that's normal. I believe that the high voltage fields are supposed to be completely isolated from the case of the motor, but I could be wrong. I know that leak hasn't existed in the past. Truth is, I have no idea what might cause that, but I have emails in to some experts who hopefully will help me with that.
The good news through all this is that at one point I had the battery pack isolated from everything else and was able to connect just the charger to it. I crossed my fingers and threw the switch. It came on, stayed on and was charging the batteries perfectly. No need for repairs there.
As for the Link-Pro and it's DC to DC converter, I have no idea why it would pass through the high voltage at one point and not another. I'm wondering if that little converter has capacitors that were storing the power. I really have no idea. Again, as far as I'm concerned, that thing is magic. But I did order a replacement DC to DC converter for a whopping $8.50 that I'll keep handy in case I need to swap out the other one.
If you made it though this and are still awake, congratulations! If you have any words of wisdom you'd like to share or guidance to offer, I'm keen to hear it. Just leave it in the comments.
Friday, February 10, 2012
Monday, November 28, 2011
More Exposure
A few weeks ago I took the car to a couple of different events, and I'm finally getting the opportunity to share it. The optimal word here is "different" as the experiences couldn't have been more different from one another. The first, was a car show.
People who've been following this blog for a while may remember that last year I was invited to bring the car to General Dynamics for their employee car show. It's worth noting that I don't work for General Dynamics, but I know someone that does, so really I'm not qualified to be there. Last year he suggested to the organizers of the event that I come. They were quite happy to have me there and I was available so I went. The car was a big hit, and when I was driving out of the parking lot, they told me they'd like me back next year. I agreed.
Well, mid-October rolled around and they did indeed contact me asking if I would bring the Z3 back for display. So the first week of November, I drove down to their offices ready to answer all the questions I knew were coming. Apparently I didn't warrant being placed with the "Premium cars" like last year. They just lined me up in some random spot on the grid. If they'd had some foresight, they would have put me next to the Nissan Leaf that showed up, but they didn't.
It turns out, it really didn't matter where I was lined up. Eventually, just like last time, there was a crowd around the car. It's really the perfect venue to show the car. This is a company full of technically oriented people, many of them engineers. Each was curious to see the project and how it was done. Several stepped forward to ask questions, many of them quite good, all picking my brain for details. There was one guy who was telling me about the car he has and the conversion he's had planned for it for some time. Hopefully, getting the chance to see a conversion first hand will inspire him to move the process along.
This was the first chance I've had to show the car with all the new safety systems in place. Of course by safety systems I mean sheets of Lexan strapped to the top of the batteries. Still, like I'd said before, you could throw a bucket of wrenches in the engine compartment and there's no way for them to short on anything. But best of all, there's no way for anyone to get their fingers on anything that could harm them. They might cut them selves on something if they stick their hand somewhere too tight, but certainly no chance to electrocution. It was very satisfying knowing that no one could hurt themselves by mistakenly touching something they shouldn't.
All in all it was a very successful event. I believe several people walked away with a more positive view of EVs.
The next day I was at an event sponsored by a local group called Gang Plank. This was set up by another local EV enthusiast who also attended EVCCON in September, Kevin Larsen. Gang Plank is what I would describe as a co-op for business start ups. They have work space and meeting spaces available to people who are interested in starting a business but don't have office space available to them. Once a week they have a brown bag session for a topic the administrators there think might interest their clients. Kevin worked with them to arrange a brown bag session concerned with converting a car to an EV. Understandably, Kevin thought it might be a good idea if I came along and gave a short presentation, show the car and answer some questions.
I thought our presentation was informative if not particularly polished. What surprised me was how supremely uninterested the group seemed to be. There were perhaps 6 people (out of 35 or so) who bothered to gather in front of the dais we used and most seemed only casually engaged in what we were saying; occasionally someone would look up. Apparently to see if we were still there. When the question and answer session came up, there were a few good ones, but I found myself answering questions more about EVs in a broader sense rather than the merits or particulars of converting a car. For instance someone asked me about the true carbon off set of an EV versus a gasoline powered car. I did my best to answer these questions, but I'm no authority on such matters. But more than anything the questions betrayed the fact that what we were presenting to them was really a few steps ahead of where they were as a group. Just the wrong audience for our material.
After the presentation, a few people and I wandered back to where the Z3 was so that they could look it over. It seemed more like something to pass their time rather than something that really interested them. The whole time I found myself hoping that the entire endeavor wasn't simply a waste of time. Everyone was very nice but no one seemed particularly interested. There was an owner of a Leaf there who was quite engaged, and we chatted for a while, but he's one of the initiated (so to speak). The whole day stood in such stark contrast to the events at the car show the day before. I took solace in the fact that if nothing else these people saw a REAL EV that's being used on a daily basis by a REAL person. Hopefully that will stick with them.
People who've been following this blog for a while may remember that last year I was invited to bring the car to General Dynamics for their employee car show. It's worth noting that I don't work for General Dynamics, but I know someone that does, so really I'm not qualified to be there. Last year he suggested to the organizers of the event that I come. They were quite happy to have me there and I was available so I went. The car was a big hit, and when I was driving out of the parking lot, they told me they'd like me back next year. I agreed.
Well, mid-October rolled around and they did indeed contact me asking if I would bring the Z3 back for display. So the first week of November, I drove down to their offices ready to answer all the questions I knew were coming. Apparently I didn't warrant being placed with the "Premium cars" like last year. They just lined me up in some random spot on the grid. If they'd had some foresight, they would have put me next to the Nissan Leaf that showed up, but they didn't.
It turns out, it really didn't matter where I was lined up. Eventually, just like last time, there was a crowd around the car. It's really the perfect venue to show the car. This is a company full of technically oriented people, many of them engineers. Each was curious to see the project and how it was done. Several stepped forward to ask questions, many of them quite good, all picking my brain for details. There was one guy who was telling me about the car he has and the conversion he's had planned for it for some time. Hopefully, getting the chance to see a conversion first hand will inspire him to move the process along.
This was the first chance I've had to show the car with all the new safety systems in place. Of course by safety systems I mean sheets of Lexan strapped to the top of the batteries. Still, like I'd said before, you could throw a bucket of wrenches in the engine compartment and there's no way for them to short on anything. But best of all, there's no way for anyone to get their fingers on anything that could harm them. They might cut them selves on something if they stick their hand somewhere too tight, but certainly no chance to electrocution. It was very satisfying knowing that no one could hurt themselves by mistakenly touching something they shouldn't.
All in all it was a very successful event. I believe several people walked away with a more positive view of EVs.
The next day I was at an event sponsored by a local group called Gang Plank. This was set up by another local EV enthusiast who also attended EVCCON in September, Kevin Larsen. Gang Plank is what I would describe as a co-op for business start ups. They have work space and meeting spaces available to people who are interested in starting a business but don't have office space available to them. Once a week they have a brown bag session for a topic the administrators there think might interest their clients. Kevin worked with them to arrange a brown bag session concerned with converting a car to an EV. Understandably, Kevin thought it might be a good idea if I came along and gave a short presentation, show the car and answer some questions.
I thought our presentation was informative if not particularly polished. What surprised me was how supremely uninterested the group seemed to be. There were perhaps 6 people (out of 35 or so) who bothered to gather in front of the dais we used and most seemed only casually engaged in what we were saying; occasionally someone would look up. Apparently to see if we were still there. When the question and answer session came up, there were a few good ones, but I found myself answering questions more about EVs in a broader sense rather than the merits or particulars of converting a car. For instance someone asked me about the true carbon off set of an EV versus a gasoline powered car. I did my best to answer these questions, but I'm no authority on such matters. But more than anything the questions betrayed the fact that what we were presenting to them was really a few steps ahead of where they were as a group. Just the wrong audience for our material.
After the presentation, a few people and I wandered back to where the Z3 was so that they could look it over. It seemed more like something to pass their time rather than something that really interested them. The whole time I found myself hoping that the entire endeavor wasn't simply a waste of time. Everyone was very nice but no one seemed particularly interested. There was an owner of a Leaf there who was quite engaged, and we chatted for a while, but he's one of the initiated (so to speak). The whole day stood in such stark contrast to the events at the car show the day before. I took solace in the fact that if nothing else these people saw a REAL EV that's being used on a daily basis by a REAL person. Hopefully that will stick with them.
Friday, November 4, 2011
It's An Imperfect World, Screws Fall Out
One of the frustrating things that occurred during this summer's work on the car was that stuff seems to have broken all on it's own. Through no intervention on my part, at least two items on the car stopped working. Trust me when I tell you I've been responsible for breaking a number of things related to the car, but I think I'm innocent here.
After I hooked the batteries back up and turned on the new TBS Link-Pro meter, I had to run through a series of menus to set it up properly. When it came to the prescaler menu, I selected the 1/10 prescaler because that's what I was using for the older Xantrex Link-10. To my surprise the meter read that my pack voltage was 68.9 volts. Well that's a bit off as my pack voltage is 160V. I double checked the meter looking through all the settings and found everything was correct. Eventually I pulled the meter out and measured the leads coming from the prescaler itself only to find that the leads which should have read 16V, instead read 6.89V. Well that put the blame solidly on the prescaler, the meter itself is fine.
I checked and the prescaler was hooked up correctly, after all I hadn't changed any of that. But there was no doubt about it, the prescaler was spitting out the wrong voltage. I have no idea why it broke, how it broke or when it broke. All I know is that when I unhooked the batteries in May, it worked, and when I put them back together in September it didn't.
Not being an expert in electronic circuits, I have no idea how to fix the prescaler. As far as I'm concerned, I put 160V on two wires that lead to a little box in which some magic happens, and then on the two wires coming out the other side, there's 16V. Besides, the unit is sealed. I was left with one option and that is to replace it.
I got the replacement 1/10 prescaler and thought I'd measure it before I disassembled the dashboard to put it in. I carefully hooked it up to the positive and negative leads to the 160V system, and to my amazement the other end read 48.3V. What the hell!? Now I had two different prescalers, each of which should be working fine, but both spit out completely different and incorrect voltages. I sent the new one back at which point they evaluated it and said it was fine. What!?
I'd ordered the part from Evolve Electrics and was working with Justin Dunn. It turned out that both of us learned something about this prescaler and the TBS meters. Both the 1/5 and the 1/10 prescalers will read 48V when hooked up to the pack. It's only after you hook it to the meter does it somehow adjust the voltage and display it properly. Like I said before, magic. Neither of us expected that. By the way, Justin was great to work with. I feel quite comfortable recommending Evolve Electrics.
The second thing that seems to have broken while the car was sitting still was the tachometer. I drove the car around for a couple days after putting it back on the road, and all was well. But one evening I left my destination to head home, turned on the lights and found that the tachometer's dial didn't light up. A few moments later I realized it wasn't working at all! It had been working when I arrived earlier when the lights weren't on. When I came to a stop light, I turned off the lights and revved the motor. Sure enough the tach sprang to life and worked perfectly. It was hovering at about 2000 RPM and I turned the lights back on and the needle froze where it was.
I have no idea what would cause such strange behavior, but I do know that I didn't touch any of those systems or their wires when I was performing the work this summer. But then it just got worse. A couple weeks ago I was accelerating from a light in second gear. At about 35 MPH I went to shift to fourth and I noticed that the tach read 5000 RPM. I thought that was odd because 35 MPH in second gear is about 4000 RPM. I dropped it into fourth and watched the needle come down to about 3000 RPM, which I know is too high for that speed. Suddenly the needle jerked up to 5000 RPM, then 6500 RPM. By the time I finished my trip, the tach's needle had moved well beyond the 8000 RPM top of the dial, and was approaching a full lap coming around to 0 again. Now the tach just jumps around all over the place providing no useful data. It's just become a distraction. I believe I'll be unhooking it.
So what the heck happened to these two pieces of equipment while they were sitting still and not being powered over the summer? I really wish I knew. The tach I can live without. I'll probably replace it at some point, but for now, it stays. Justin sent the prescaler back to me and I popped it in yesterday. It works just fine and the meter is behaving like I expected. If you ever end up with the TBS meter and prescaler combo, don't bother taking a voltage measurement from the prescaler itself, it won't be what you expect it should be. It has to be hooked up to the meter.
After I hooked the batteries back up and turned on the new TBS Link-Pro meter, I had to run through a series of menus to set it up properly. When it came to the prescaler menu, I selected the 1/10 prescaler because that's what I was using for the older Xantrex Link-10. To my surprise the meter read that my pack voltage was 68.9 volts. Well that's a bit off as my pack voltage is 160V. I double checked the meter looking through all the settings and found everything was correct. Eventually I pulled the meter out and measured the leads coming from the prescaler itself only to find that the leads which should have read 16V, instead read 6.89V. Well that put the blame solidly on the prescaler, the meter itself is fine.
I checked and the prescaler was hooked up correctly, after all I hadn't changed any of that. But there was no doubt about it, the prescaler was spitting out the wrong voltage. I have no idea why it broke, how it broke or when it broke. All I know is that when I unhooked the batteries in May, it worked, and when I put them back together in September it didn't.
Not being an expert in electronic circuits, I have no idea how to fix the prescaler. As far as I'm concerned, I put 160V on two wires that lead to a little box in which some magic happens, and then on the two wires coming out the other side, there's 16V. Besides, the unit is sealed. I was left with one option and that is to replace it.
I got the replacement 1/10 prescaler and thought I'd measure it before I disassembled the dashboard to put it in. I carefully hooked it up to the positive and negative leads to the 160V system, and to my amazement the other end read 48.3V. What the hell!? Now I had two different prescalers, each of which should be working fine, but both spit out completely different and incorrect voltages. I sent the new one back at which point they evaluated it and said it was fine. What!?
I'd ordered the part from Evolve Electrics and was working with Justin Dunn. It turned out that both of us learned something about this prescaler and the TBS meters. Both the 1/5 and the 1/10 prescalers will read 48V when hooked up to the pack. It's only after you hook it to the meter does it somehow adjust the voltage and display it properly. Like I said before, magic. Neither of us expected that. By the way, Justin was great to work with. I feel quite comfortable recommending Evolve Electrics.
The second thing that seems to have broken while the car was sitting still was the tachometer. I drove the car around for a couple days after putting it back on the road, and all was well. But one evening I left my destination to head home, turned on the lights and found that the tachometer's dial didn't light up. A few moments later I realized it wasn't working at all! It had been working when I arrived earlier when the lights weren't on. When I came to a stop light, I turned off the lights and revved the motor. Sure enough the tach sprang to life and worked perfectly. It was hovering at about 2000 RPM and I turned the lights back on and the needle froze where it was.
I have no idea what would cause such strange behavior, but I do know that I didn't touch any of those systems or their wires when I was performing the work this summer. But then it just got worse. A couple weeks ago I was accelerating from a light in second gear. At about 35 MPH I went to shift to fourth and I noticed that the tach read 5000 RPM. I thought that was odd because 35 MPH in second gear is about 4000 RPM. I dropped it into fourth and watched the needle come down to about 3000 RPM, which I know is too high for that speed. Suddenly the needle jerked up to 5000 RPM, then 6500 RPM. By the time I finished my trip, the tach's needle had moved well beyond the 8000 RPM top of the dial, and was approaching a full lap coming around to 0 again. Now the tach just jumps around all over the place providing no useful data. It's just become a distraction. I believe I'll be unhooking it.
So what the heck happened to these two pieces of equipment while they were sitting still and not being powered over the summer? I really wish I knew. The tach I can live without. I'll probably replace it at some point, but for now, it stays. Justin sent the prescaler back to me and I popped it in yesterday. It works just fine and the meter is behaving like I expected. If you ever end up with the TBS meter and prescaler combo, don't bother taking a voltage measurement from the prescaler itself, it won't be what you expect it should be. It has to be hooked up to the meter.
Monday, October 31, 2011
Safety Issues
While at EVCCON, I spent a good deal of time looking at and admiring all the conversion, and trying to get ideas for how I might improve the Z3. Among the things that made an impression on me was the fact that the constructors of virtually all the EVs had made a great deal of effort to make the car's motor bays "touch safe." The Illuminati team mentioned that during the X-Prize contest, they were required to shows that all the compartments that held batteries and electronics were also "wrench safe." Meaning that you could throw a wrench into any compartment or area in the car and there was no danger of a short or explosion.
It became clear to me that I'd fallen short in this area. I never really considered putting much effort into making the z3 "touch safe" or "wrench safe" figuring I was the only one in that area, and I know what's safe and what isn't so why does it matter? But as I watched all these people milling around my car, I found myself with an unusually high level of anxiety worrying about someone hurting them self. Several times people leaned over the motor and battery compartment to get a close look at something, only to have their EVCCON lanyard drag across the top of the cells. In fact a local boy came in to look at the neat cars. I explained to him not to touch anything for safety reasons, but then watched him like a hawk to be sure he was safe.
I realized at that time that not only would making the whole motor compartment touch safe be a good idea, it was essential. Here's the thing... I never anticipated that the car would draw as much attention as it does. I never envisioned that I'd be taking it to car shows and there would be strange people so interested in it and getting so close to it to inspect it. Imagine what the news media (especially Fox News) would say if some hapless person were accidentally injured, or worse, by an electric car at some car show. In one fell swoop, I'd be responsible for not only injuring or perhaps killing some poor soul, but the EV movement as well!
At the public car show the last day of the conference, one of the attendees, David Hrivnak, made a point of pulling me aside and asking me what I intended to do about the safety issues. Not "are you thinking about doing something?", but "what are you going to do?" David clearly recognized the risks I was exposed to and the implications, and had the courage to bring it to me. By that time I had already got it. I was absolutely on the same page as David. I understood what was at stake and the imperative to resolve the safety concerns he, and by that time, I had. Thanks again David, I'm very grateful.
I had been looking at the other cars to see which ideas of theirs I could steal. What I saw was basically two ways of covering the batteries, terminal and high voltage connections, if they were in an area where they were exposed. Either they were sealed in a custom built box, or they were simply covered with plastic. For anyone who's seen the Z3 or the pictures of it, you know there is no room to redo things in order to incorporate battery boxes. That meant I was going to need to figure out how to simply cover the terminals of the batteries. In addition, I needed to figure out how to cover the electrics bay where the controller and contactor are. That bay is the only placed where the positive terminal is exposed that has full pack voltage.
After a little research I learned that the best material was probably Lexan, so I purchased some from the local hardware store and started measuring and cutting. Cutting Lexan is not too difficult. There are special blades available to cut it, or you can cut it with a thin blade, fine toothed saw. When you cut it with a blade, you simply score the same line 15 or 20 times and then bend the plastic to kind of tear it through the rest of the way.
I knew the front batteries were going to be the most difficult to cover. It looks easy enough, but the clearance between the front corner of the batteries and the hood is as little as 1/2". So to place a piece of Lexan on top of the terminals and run it straight to the edge of the batteries would certainly be hit by the hood once it was shut. It would require careful cutting and measuring to make it fit. Since you can't actually see the space once the hood is closed, I used Play Dough to figure out the clearances. I simply shaped a chunk of it to the size I needed and laid it on the area where I thought the battery cover and the hood touch. Then I shut and opened the hood and inspected the Play Dough. You can easily see where it's been crushed too thin, or even pierced. That's where I needed to trim and do some more fitting.
Ultimately I found I needed to bend the front edges of the cover to clear the hood. I found a piece of scrap Lexan, and sicked my heat gun on it. I used the low setting thinking that I didn't want to heat it too fast and potentially over melt or set the piece on fire. It worked pretty well but I found that when I tried to bend a longer edge, the plastic started to show bubbles inside by the time it finally started to wilt. I tried the higher temperature and that turned out to work much better. First, it was faster, but second since the plastic was exposed to the heat for a much shorter period of time, so there was no time for those bubbles to appear. So, higher heat yielded a much cleaner looking bend.
In the detail shot you can see what I mean about the plastic bubbling under the heat gun. Structurally, it seems fine, but cosmetically it's kind of ugly. You can also see the slots that I cut into the plastic and the clips I'm using to hold the piece in place. These clips are an assembly of two channel clips used to hold a mirror up to a wall. This works fine, but admittedly it's ugly. I'd love to have come up with a better way to hold this cover down, but this was the best thing I could think of. I also drilled little 3/32" holes in the Lexan next to each of the positive terminals. This way I can stick the probe of my multi-meter through the plastic to measure any one or group of batteries I want.
On the larger set of batteries I used D-hooks mounted to the aluminum frame and Velcro straps to hold the piece down in place. Again, not the best looking solution. You can see that the plastic follows the curve of the batteries nicely. In the detail shot, you can see that I was able to shape the plastic to accommodate the 2/0 cable coming off the pack, and turn the corner down just a bit to make it less lethal. I used high heat to make these bends; notice the difference in the plastic from the first bends I made. It looks much better.
The cover over the electrics bay took a lot more fiddling and cutting to get it just right. It rests nicely in the grove just below the cushy part of the rubber that seals the area from the elements when the hood is closed. I made a template out of cardboard and then trimmed the plastic to shape. As it happened, I'd run out of Lexan and the only sheets at the store were either too small or way too big (and expensive). So I used an acrylic sheet instead. I can see why people said that Lexan is better. Acrylic is much more prone to snapping, cracking and chipping. I was able to get it done, but it would have been way easier with Lexan.
There is still one more safety concern I need to address, and that's an emergency cut off switch. You may remember that I had the big red slap switch under the hood, but there were two problems with that. One, I had no way of actually slapping it in the event of an emergency, that is if I were in the car driving it, and two, it melted. At some point, enough current went through it that one of the internal contact points melted. You can see pictures of that from a couple posts ago if you wish. To replace it, I got this unit:
This needs to be mounted either in the cabin so that the driver can reach it while moving, or I need to rig up some way of actuating it from in the cabin. I'm thinking that a push/pull cable mounted to the handle should work well. The questions remaining are, where do I mount the switch and where and how do I mount the cable? As of now, I have no idea about either.
It became clear to me that I'd fallen short in this area. I never really considered putting much effort into making the z3 "touch safe" or "wrench safe" figuring I was the only one in that area, and I know what's safe and what isn't so why does it matter? But as I watched all these people milling around my car, I found myself with an unusually high level of anxiety worrying about someone hurting them self. Several times people leaned over the motor and battery compartment to get a close look at something, only to have their EVCCON lanyard drag across the top of the cells. In fact a local boy came in to look at the neat cars. I explained to him not to touch anything for safety reasons, but then watched him like a hawk to be sure he was safe.
I realized at that time that not only would making the whole motor compartment touch safe be a good idea, it was essential. Here's the thing... I never anticipated that the car would draw as much attention as it does. I never envisioned that I'd be taking it to car shows and there would be strange people so interested in it and getting so close to it to inspect it. Imagine what the news media (especially Fox News) would say if some hapless person were accidentally injured, or worse, by an electric car at some car show. In one fell swoop, I'd be responsible for not only injuring or perhaps killing some poor soul, but the EV movement as well!
At the public car show the last day of the conference, one of the attendees, David Hrivnak, made a point of pulling me aside and asking me what I intended to do about the safety issues. Not "are you thinking about doing something?", but "what are you going to do?" David clearly recognized the risks I was exposed to and the implications, and had the courage to bring it to me. By that time I had already got it. I was absolutely on the same page as David. I understood what was at stake and the imperative to resolve the safety concerns he, and by that time, I had. Thanks again David, I'm very grateful.
I had been looking at the other cars to see which ideas of theirs I could steal. What I saw was basically two ways of covering the batteries, terminal and high voltage connections, if they were in an area where they were exposed. Either they were sealed in a custom built box, or they were simply covered with plastic. For anyone who's seen the Z3 or the pictures of it, you know there is no room to redo things in order to incorporate battery boxes. That meant I was going to need to figure out how to simply cover the terminals of the batteries. In addition, I needed to figure out how to cover the electrics bay where the controller and contactor are. That bay is the only placed where the positive terminal is exposed that has full pack voltage.
After a little research I learned that the best material was probably Lexan, so I purchased some from the local hardware store and started measuring and cutting. Cutting Lexan is not too difficult. There are special blades available to cut it, or you can cut it with a thin blade, fine toothed saw. When you cut it with a blade, you simply score the same line 15 or 20 times and then bend the plastic to kind of tear it through the rest of the way.
I knew the front batteries were going to be the most difficult to cover. It looks easy enough, but the clearance between the front corner of the batteries and the hood is as little as 1/2". So to place a piece of Lexan on top of the terminals and run it straight to the edge of the batteries would certainly be hit by the hood once it was shut. It would require careful cutting and measuring to make it fit. Since you can't actually see the space once the hood is closed, I used Play Dough to figure out the clearances. I simply shaped a chunk of it to the size I needed and laid it on the area where I thought the battery cover and the hood touch. Then I shut and opened the hood and inspected the Play Dough. You can easily see where it's been crushed too thin, or even pierced. That's where I needed to trim and do some more fitting.
Ultimately I found I needed to bend the front edges of the cover to clear the hood. I found a piece of scrap Lexan, and sicked my heat gun on it. I used the low setting thinking that I didn't want to heat it too fast and potentially over melt or set the piece on fire. It worked pretty well but I found that when I tried to bend a longer edge, the plastic started to show bubbles inside by the time it finally started to wilt. I tried the higher temperature and that turned out to work much better. First, it was faster, but second since the plastic was exposed to the heat for a much shorter period of time, so there was no time for those bubbles to appear. So, higher heat yielded a much cleaner looking bend.
In the detail shot you can see what I mean about the plastic bubbling under the heat gun. Structurally, it seems fine, but cosmetically it's kind of ugly. You can also see the slots that I cut into the plastic and the clips I'm using to hold the piece in place. These clips are an assembly of two channel clips used to hold a mirror up to a wall. This works fine, but admittedly it's ugly. I'd love to have come up with a better way to hold this cover down, but this was the best thing I could think of. I also drilled little 3/32" holes in the Lexan next to each of the positive terminals. This way I can stick the probe of my multi-meter through the plastic to measure any one or group of batteries I want.
On the larger set of batteries I used D-hooks mounted to the aluminum frame and Velcro straps to hold the piece down in place. Again, not the best looking solution. You can see that the plastic follows the curve of the batteries nicely. In the detail shot, you can see that I was able to shape the plastic to accommodate the 2/0 cable coming off the pack, and turn the corner down just a bit to make it less lethal. I used high heat to make these bends; notice the difference in the plastic from the first bends I made. It looks much better.
The cover over the electrics bay took a lot more fiddling and cutting to get it just right. It rests nicely in the grove just below the cushy part of the rubber that seals the area from the elements when the hood is closed. I made a template out of cardboard and then trimmed the plastic to shape. As it happened, I'd run out of Lexan and the only sheets at the store were either too small or way too big (and expensive). So I used an acrylic sheet instead. I can see why people said that Lexan is better. Acrylic is much more prone to snapping, cracking and chipping. I was able to get it done, but it would have been way easier with Lexan.
There is still one more safety concern I need to address, and that's an emergency cut off switch. You may remember that I had the big red slap switch under the hood, but there were two problems with that. One, I had no way of actually slapping it in the event of an emergency, that is if I were in the car driving it, and two, it melted. At some point, enough current went through it that one of the internal contact points melted. You can see pictures of that from a couple posts ago if you wish. To replace it, I got this unit:
This needs to be mounted either in the cabin so that the driver can reach it while moving, or I need to rig up some way of actuating it from in the cabin. I'm thinking that a push/pull cable mounted to the handle should work well. The questions remaining are, where do I mount the switch and where and how do I mount the cable? As of now, I have no idea about either.
Wednesday, September 28, 2011
EVCCON 2011
I've finally arrived back in Arizona after having attended the first EVCCON (EV Conversion Conference) in Missouri. I rented a car hauler from U-Haul, borrowed my sister's truck, loaded up the Z3 and then my father and I towed the car 1500 miles to Cape Girardeau. For those of you unfamiliar with the convention, it was put on by the EVTV crew, Jack Rickard and Brian Noto. The idea was to have the people that have adopted the use of, or are interested in EVs with LiFePo4 batteries, come together.
To be honest, I simply had no idea what to expect. My biggest hope was that there would be time to meet with the other attendees and exchange ideas and then see some of the cars up close. The schedule that was printed up was pretty full and I was concerned there wouldn't be much of a chance for that. The convention was scheduled to officially start around 10:00 AM Wednesday. As it turned out, quite a people showed up on Tuesday and began descending on the EVTV shop. We arrived at the hotel Tuesday around 4:00 PM and immediately ran into Mark Emon, one of the finalists for the EVTV $20,000 EV component give away contest. Mark was getting ready to run down to the shop and said that we should come along and drop the car off. We decided we'd follow along and do just that.
When we arrived, there were already 30 or so people gathered around looking at the E-Cobra that Jack and Brian have been working on. Everyone encouraged me to unload the Z3 and then proceeded help. I pulled the truck into the shop (a tight fit) and used one of the ramps inside to facilitate getting it off the trailer nice, quick and painless. Once it was off the trailer, I opened it up so everyone could have a look. There were certainly lots of favorable comments and questions, and it was fun answering them all. Jack explained to me that people started showing up well before the appointed time (some as early as Monday morning) and took over his shop. Though that clearly wasn't the plan, I think he was quite happy to have everyone there. Around dinner time, someone showed up with several pizza's and we all sat around talking about EVs and sharing pizza and beer. I don't know that it gets much better than that. Before I left I asked Jack where he wanted me to put my car and he told me to just park it next to a couple of the others.
The Z3 has never been in better company, nor so thoroughly out classed.
Wednesday we arrived at the shop around 10:00 AM and found that it was already teaming with activity. The previous day, they'd put the final pieces together in the E-Cobra and tried to drive it, but found it would not move under it's own power. Motor spun, but in spite of the fact that the clutch was firmly engaged the car wouldn't move. Six to eight guys were working on it and pulling the transmission to see if they could determine the problem with the clutch. As the day went on, more and more cars arrived, each impressive and a joy to look over. Sebastian Bourgeois' 911, Fred Behning's 1960 Austin Healey Sprite, Charlie and Tamera Rickman's 1973 Opel GT and Daniel Yohannes' Porsche Cayenne just to name a few.
Fred Behning's Austin Healey Bugeye Sprite. One of my favorites.
The back end of Sebastian Bourgeois' 911. Yes, there are two motors in that space, one on top of the other.
Eric Kriss' 356 Porsche replica. An astonishingly beautiful build.
A peek into the back end of Duane Ball's Porsche 904 replica. Another gorgeous conversion.
I can't express what a joy it was to talk to each and everyone of these great people. Instead of the first two questions out of everyone's mouth being "How far will it go?" and "How long to charge it?", they were asking great questions like "How did you solve this problem?" or "Why did you choose that design?" Starting off with a pool of people that already "get it" set the stage for some very substantial, entertaining and valuable conversations. This was truly a fantastic day.
The next two days took place at Jack's hanger out at the Cape Girardeau airport and were comprised mostly of various speakers and eating (man, there was a lot of food). The speakers lined up ranged from individuals that own and run conversion shops, suppliers of EV components (both sellers and manufacturers), industry analysts, with a couple of speakers on technical issues thrown in for good measure. I had no expectations for most of the speakers and very high expectations for others. As it turned out, each speaker was quite good. A few stood out, having put together truly informative and interesting talks, but also delivering them quite well. George Hamstra from Netgain motors gave two talks, both packed with information about where we, as a global community, are going in regards to oil usage. Eric Kriss delivered a terrific analysis of why EVs make sense now and why and how that's come to pass. Ryan Bohm of EVSource delivered a great talk about a variety of topics related to EVs including details of the new WarP-Drive controllers and safety concerns regarding EVs. The latter made a big impression on everyone. It was well stated and impassioned.
Thursday evening, Chris Paine, director of "Who Killed the Electric Car" and "Revenge of the Electric Car" gave a talk. It was an interesting talk, but largely about the concerns and issues surrounding making movies. He is, however, clearly passionate about EVs. After speaking for an hour or so, and madly texting and emailing his producer to get permission to show us "Revenge of the Electric Car" he had still not received the OK. Ultimately he took the decision into his own hands and rolled the film. It's set to come out October/November in different cities, so it was a great opportunity to see it early.
The film was basically an overview of four different groups, or in one case a person, working to bring an EV to the market. It featured, Bob Lutz and his efforts at shepherding the Volt into production at Chevy, Elon Musk and Tesla's saga, Carlos Ghosn and Nissan's preemptive dive into the EV world, and finally Rev. Gadget and his attempts to put together a 120 mile range Porsche 356 replica conversion that he can market. It was basically a documentary on the difficulties, setbacks and successes of each. It was well worth seeing and very entertaining. When it comes to your city, I think it's worth your time.
Later in the day on Friday, we all went out to the runways behind the hanger for some festivities with the cars, including weighing each, a drag race, and an auto cross set up by the local SCCA. The Z3 came in at 3285 lbs, which is rather portly compared to several others, being that so many of the cars there were built from light weight sports cars, or replicas. (A side note, and I don't remember the source, but the stock Z3 actually weighed more than a standard 2 door E36, BMW 3 series chassis.) What I thought was odd was the weight was dead on identical to when I had it weighed after it hit the road a year and a half ago, but the weight distribution went from 52% / 48% front to rear weight bias, to 50% / 50%. Can't explain that.
I've never participated in any sort of drag race. Not the official sort on a track, or the race off the line at the local street light. It's just not my thing. But I have to admit, it was great to find out just how well the Z3 would perform in an official, measured way. As it turned out, my car was the first weighed and the first at the line to run the 1/4 mile. It took some time for the next car to get weighed and staged. When we were all set, the lights on the tree (that's drag racing talk for a pole with lights on it) gave us the green to go. I started in 2nd gear and screeched the tires like mad, much to the crowd's approval, but I knew that meant I'd lost time. At the end of the run, I left it in 4th, which meant my torque was dying off, and I lifted just before the end. Like I said, I've never done this. But I realized right away I could do better. So the first run was 19.2 seconds at 61.8 MPH.
I lined up to try again. This time I started in 3rd and hit the power with a bit more care to be sure not to spin the tires. When 4th was losing torque I went to 5th, and I could feel a bit more torque kick in. That run was better at 18.9 seconds, 66.4 MPH. All in all, in a field of 22 cars, the Z3 came in a respectable 9th. Aside from Ron Adamowicz's purpose built Camaro drag racer (which was awesome) the top runner was Dave Hrivnak's Tesla Roadster that ran it in 13.1 at 88.2 MPH. Later, Dave gave me a ride in the Tesla, for which I will remain eternally grateful. He took me down the 1/4 mile run. I don't think I've ever experienced anything so blisteringly fast. I'm not even sure the magnetically launched roller coasters I've ridden accelerate that fast. It was simply astonishing.
Having run what I thought was likely the best 1/4 mile I could, I went over to the auto cross. I picked out a helmet and was given an instructor. He explained to me how to read the course and how to attack various corners. We set off on the first lap and I did fairly well finishing in the mid 50 second range. But the instructor said "This car has a lot more to give, so I know you can do better." I knew he was right since I hadn't caused the tires to squeal once. Within a couple more laps I was down in the upper 40's. I ran several more times trimming off a little more each time. The car performed great! I was throwing it into corners and driving it like it was meant to be driven. The last big corner you hit at pretty good speed and I was nearly drifting around it, the back end just barely hanging on. When it was all said and done, it got down to 44.7 seconds. Not the best time, but in the top of the pack. It would likely come as no surprise, but the Tesla set the best time in the mid 41's.
Ultimately I had to stop because I was running low on charge. That was the most fun I've ever had in a car, and that includes a few memorable nights in high school and college ;)
Saturday, we wrapped up at the hanger and then all of the cars drove down to a park in the middle of town for an EV car show. Each of the cars was on display and each builder was available to answer all the normal questions posed by people just seeing EVs for the first time. It was a great crowd and there were a number of people from the media there to film and photograph the cars as well as interview the drivers. We left the park in a police escorted parade around Cape Girardeau. Here is a fantastic video put together by one of the participants. He highlights each car and puts some information up about each (though he did get a few facts wrong on mine, it has an 11 inch motor!).
At the end of the parade, all the cars were gathered in the parking lot of the hotel, parked and arranged ever so carefully for some photos. First the cars by themselves, and then all the owners went and stood by the cars. Sadly, I did not have may camera. I'm hoping that one of the kind people that has a copy will send one to me.
It's difficult to put into words, but that was a profound and powerful moment. I think everyone felt it and knew it was important. There was something palpable in the air. The sense that this was the beginning, the beginning of something big. Sure manufacturers are going to begin producing EVs for the public. But I, and I think everyone there feels that a big part of the future of EVs will be conversions. We were there to bare witness to the beginning of a movement that will change the world.
To be honest, I simply had no idea what to expect. My biggest hope was that there would be time to meet with the other attendees and exchange ideas and then see some of the cars up close. The schedule that was printed up was pretty full and I was concerned there wouldn't be much of a chance for that. The convention was scheduled to officially start around 10:00 AM Wednesday. As it turned out, quite a people showed up on Tuesday and began descending on the EVTV shop. We arrived at the hotel Tuesday around 4:00 PM and immediately ran into Mark Emon, one of the finalists for the EVTV $20,000 EV component give away contest. Mark was getting ready to run down to the shop and said that we should come along and drop the car off. We decided we'd follow along and do just that.
The Z3 has never been in better company, nor so thoroughly out classed.
Wednesday we arrived at the shop around 10:00 AM and found that it was already teaming with activity. The previous day, they'd put the final pieces together in the E-Cobra and tried to drive it, but found it would not move under it's own power. Motor spun, but in spite of the fact that the clutch was firmly engaged the car wouldn't move. Six to eight guys were working on it and pulling the transmission to see if they could determine the problem with the clutch. As the day went on, more and more cars arrived, each impressive and a joy to look over. Sebastian Bourgeois' 911, Fred Behning's 1960 Austin Healey Sprite, Charlie and Tamera Rickman's 1973 Opel GT and Daniel Yohannes' Porsche Cayenne just to name a few.
I can't express what a joy it was to talk to each and everyone of these great people. Instead of the first two questions out of everyone's mouth being "How far will it go?" and "How long to charge it?", they were asking great questions like "How did you solve this problem?" or "Why did you choose that design?" Starting off with a pool of people that already "get it" set the stage for some very substantial, entertaining and valuable conversations. This was truly a fantastic day.
The next two days took place at Jack's hanger out at the Cape Girardeau airport and were comprised mostly of various speakers and eating (man, there was a lot of food). The speakers lined up ranged from individuals that own and run conversion shops, suppliers of EV components (both sellers and manufacturers), industry analysts, with a couple of speakers on technical issues thrown in for good measure. I had no expectations for most of the speakers and very high expectations for others. As it turned out, each speaker was quite good. A few stood out, having put together truly informative and interesting talks, but also delivering them quite well. George Hamstra from Netgain motors gave two talks, both packed with information about where we, as a global community, are going in regards to oil usage. Eric Kriss delivered a terrific analysis of why EVs make sense now and why and how that's come to pass. Ryan Bohm of EVSource delivered a great talk about a variety of topics related to EVs including details of the new WarP-Drive controllers and safety concerns regarding EVs. The latter made a big impression on everyone. It was well stated and impassioned.
Thursday evening, Chris Paine, director of "Who Killed the Electric Car" and "Revenge of the Electric Car" gave a talk. It was an interesting talk, but largely about the concerns and issues surrounding making movies. He is, however, clearly passionate about EVs. After speaking for an hour or so, and madly texting and emailing his producer to get permission to show us "Revenge of the Electric Car" he had still not received the OK. Ultimately he took the decision into his own hands and rolled the film. It's set to come out October/November in different cities, so it was a great opportunity to see it early.
The film was basically an overview of four different groups, or in one case a person, working to bring an EV to the market. It featured, Bob Lutz and his efforts at shepherding the Volt into production at Chevy, Elon Musk and Tesla's saga, Carlos Ghosn and Nissan's preemptive dive into the EV world, and finally Rev. Gadget and his attempts to put together a 120 mile range Porsche 356 replica conversion that he can market. It was basically a documentary on the difficulties, setbacks and successes of each. It was well worth seeing and very entertaining. When it comes to your city, I think it's worth your time.
Later in the day on Friday, we all went out to the runways behind the hanger for some festivities with the cars, including weighing each, a drag race, and an auto cross set up by the local SCCA. The Z3 came in at 3285 lbs, which is rather portly compared to several others, being that so many of the cars there were built from light weight sports cars, or replicas. (A side note, and I don't remember the source, but the stock Z3 actually weighed more than a standard 2 door E36, BMW 3 series chassis.) What I thought was odd was the weight was dead on identical to when I had it weighed after it hit the road a year and a half ago, but the weight distribution went from 52% / 48% front to rear weight bias, to 50% / 50%. Can't explain that.
I've never participated in any sort of drag race. Not the official sort on a track, or the race off the line at the local street light. It's just not my thing. But I have to admit, it was great to find out just how well the Z3 would perform in an official, measured way. As it turned out, my car was the first weighed and the first at the line to run the 1/4 mile. It took some time for the next car to get weighed and staged. When we were all set, the lights on the tree (that's drag racing talk for a pole with lights on it) gave us the green to go. I started in 2nd gear and screeched the tires like mad, much to the crowd's approval, but I knew that meant I'd lost time. At the end of the run, I left it in 4th, which meant my torque was dying off, and I lifted just before the end. Like I said, I've never done this. But I realized right away I could do better. So the first run was 19.2 seconds at 61.8 MPH.
I lined up to try again. This time I started in 3rd and hit the power with a bit more care to be sure not to spin the tires. When 4th was losing torque I went to 5th, and I could feel a bit more torque kick in. That run was better at 18.9 seconds, 66.4 MPH. All in all, in a field of 22 cars, the Z3 came in a respectable 9th. Aside from Ron Adamowicz's purpose built Camaro drag racer (which was awesome) the top runner was Dave Hrivnak's Tesla Roadster that ran it in 13.1 at 88.2 MPH. Later, Dave gave me a ride in the Tesla, for which I will remain eternally grateful. He took me down the 1/4 mile run. I don't think I've ever experienced anything so blisteringly fast. I'm not even sure the magnetically launched roller coasters I've ridden accelerate that fast. It was simply astonishing.
Having run what I thought was likely the best 1/4 mile I could, I went over to the auto cross. I picked out a helmet and was given an instructor. He explained to me how to read the course and how to attack various corners. We set off on the first lap and I did fairly well finishing in the mid 50 second range. But the instructor said "This car has a lot more to give, so I know you can do better." I knew he was right since I hadn't caused the tires to squeal once. Within a couple more laps I was down in the upper 40's. I ran several more times trimming off a little more each time. The car performed great! I was throwing it into corners and driving it like it was meant to be driven. The last big corner you hit at pretty good speed and I was nearly drifting around it, the back end just barely hanging on. When it was all said and done, it got down to 44.7 seconds. Not the best time, but in the top of the pack. It would likely come as no surprise, but the Tesla set the best time in the mid 41's.
Ultimately I had to stop because I was running low on charge. That was the most fun I've ever had in a car, and that includes a few memorable nights in high school and college ;)
Saturday, we wrapped up at the hanger and then all of the cars drove down to a park in the middle of town for an EV car show. Each of the cars was on display and each builder was available to answer all the normal questions posed by people just seeing EVs for the first time. It was a great crowd and there were a number of people from the media there to film and photograph the cars as well as interview the drivers. We left the park in a police escorted parade around Cape Girardeau. Here is a fantastic video put together by one of the participants. He highlights each car and puts some information up about each (though he did get a few facts wrong on mine, it has an 11 inch motor!).
At the end of the parade, all the cars were gathered in the parking lot of the hotel, parked and arranged ever so carefully for some photos. First the cars by themselves, and then all the owners went and stood by the cars. Sadly, I did not have may camera. I'm hoping that one of the kind people that has a copy will send one to me.
It's difficult to put into words, but that was a profound and powerful moment. I think everyone felt it and knew it was important. There was something palpable in the air. The sense that this was the beginning, the beginning of something big. Sure manufacturers are going to begin producing EVs for the public. But I, and I think everyone there feels that a big part of the future of EVs will be conversions. We were there to bare witness to the beginning of a movement that will change the world.
Wednesday, September 14, 2011
Cool Air
I took the Z3 down to the shop today to have the A/C lines evacuated and charged. I had to explain to the technician that was going to drive the car into the service bay how to operate the car. I wanted to make sure he was comfortable. There really is no trick to starting and driving it, but the lack of noise can throw people off.
After an hour and a half or so, the service rep came out to ask me if the oil that ships in the compressor has any dye in it. "Why, are you seeing dye?" They weren't, but he explained that the system was not holding a vacuum and they couldn't pin point the location of the leak. So they were thinking of putting some refrigerant in system to see if they could see the leak when it spit out colored stuff. The thing is, it's the oil in the systems they use that contain the dye when they want to track a leak, but we can't contaminate the MasterFlux system with standard oil for A/C units because it uses a special type of oil.
I asked them to do what they could to find the leak and moped back to my seat dreading having to take the system apart again. About 45 minutes later, the tech that drove the car into the service bay came back and asked me how much refrigerant they should put in the system. He explained that they'd put just under 2 lbs. in and it wasn't quite as cold as they like to see. Uh, what? I thought it wasn't sealing properly? He explained that it didn't under vacuum, but once they put refrigerant in the system, it seemed to be holding pressure just fine.
No one seemed to really know why this would be the case, or how something like this might happen. But the service rep hazarded a guess. He was thinking that the seals in the system may simply have been allowing air into the system when they were drawing the vacuum down because they'd dried out from the system being empty for so long, but once they turned the compressor on and the oil started flowing around the innards of the system, it may have lubricated the O-rings and helped them seat. Since no one had a better idea than that, we decided that must be it.
They put a thermometer in the vent and let the system run for several minutes to get a temperature reading of the out put. It read 60 °F. That is on the high end of normal. He noted that the high pressure side of the system had lower pressure than they're used to seeing. While I don't know this to be the case, my suspicion is that this system, which is designed to run between 120 and 420 VDC is operating at the low end of the scale in my car at only 160 V. So my guess is that it simply doesn't have the voltage behind it to drive it hard enough to get higher pressures.
In any event, the drive home was very pleasant. The compressor is pretty quiet. Standing over it while it's running, you hear a tick-tick-tick-tick sound, but its not particularly harsh or disturbing. Inside the car, I can feel it more than I can hear it. Well I can't really hear it from in the car, but I can feel it in my feet. Without it being mounted on those rubber bushings, I'm sure it would be very shaky indeed. All in all, I'm pleased. I would have liked another 10 °F temperature drop, but this is so much better than no A/C, I'm not complaining. I will be keeping an eye on it over the next few days, weeks, months to see if the output changes. I'm not convinced there's no leak just yet.
I also had them align the front end so that it has 0° toe-in. Normally cars are aligned with a slight 1 to 2° toe-in for tracking purposes. Without that, cars will tend to wander about the road, potentially following cracks or grooves in the pavement. Not a desirable trait really, but neither is an EV that uses more energy that in needs by scrubbing it off with the tires. As it turns out, they didn't have to adjust it much, and like I said yesterday, I really don't know if it's had an impact yet. On that note, I did receive the new 1/10 pre-scalar today, which will allow me to measure energy in and out again. Now I get to begin the long, arduous task of disassembling the passenger side dashboard.
After an hour and a half or so, the service rep came out to ask me if the oil that ships in the compressor has any dye in it. "Why, are you seeing dye?" They weren't, but he explained that the system was not holding a vacuum and they couldn't pin point the location of the leak. So they were thinking of putting some refrigerant in system to see if they could see the leak when it spit out colored stuff. The thing is, it's the oil in the systems they use that contain the dye when they want to track a leak, but we can't contaminate the MasterFlux system with standard oil for A/C units because it uses a special type of oil.
I asked them to do what they could to find the leak and moped back to my seat dreading having to take the system apart again. About 45 minutes later, the tech that drove the car into the service bay came back and asked me how much refrigerant they should put in the system. He explained that they'd put just under 2 lbs. in and it wasn't quite as cold as they like to see. Uh, what? I thought it wasn't sealing properly? He explained that it didn't under vacuum, but once they put refrigerant in the system, it seemed to be holding pressure just fine.
No one seemed to really know why this would be the case, or how something like this might happen. But the service rep hazarded a guess. He was thinking that the seals in the system may simply have been allowing air into the system when they were drawing the vacuum down because they'd dried out from the system being empty for so long, but once they turned the compressor on and the oil started flowing around the innards of the system, it may have lubricated the O-rings and helped them seat. Since no one had a better idea than that, we decided that must be it.
They put a thermometer in the vent and let the system run for several minutes to get a temperature reading of the out put. It read 60 °F. That is on the high end of normal. He noted that the high pressure side of the system had lower pressure than they're used to seeing. While I don't know this to be the case, my suspicion is that this system, which is designed to run between 120 and 420 VDC is operating at the low end of the scale in my car at only 160 V. So my guess is that it simply doesn't have the voltage behind it to drive it hard enough to get higher pressures.
In any event, the drive home was very pleasant. The compressor is pretty quiet. Standing over it while it's running, you hear a tick-tick-tick-tick sound, but its not particularly harsh or disturbing. Inside the car, I can feel it more than I can hear it. Well I can't really hear it from in the car, but I can feel it in my feet. Without it being mounted on those rubber bushings, I'm sure it would be very shaky indeed. All in all, I'm pleased. I would have liked another 10 °F temperature drop, but this is so much better than no A/C, I'm not complaining. I will be keeping an eye on it over the next few days, weeks, months to see if the output changes. I'm not convinced there's no leak just yet.
I also had them align the front end so that it has 0° toe-in. Normally cars are aligned with a slight 1 to 2° toe-in for tracking purposes. Without that, cars will tend to wander about the road, potentially following cracks or grooves in the pavement. Not a desirable trait really, but neither is an EV that uses more energy that in needs by scrubbing it off with the tires. As it turns out, they didn't have to adjust it much, and like I said yesterday, I really don't know if it's had an impact yet. On that note, I did receive the new 1/10 pre-scalar today, which will allow me to measure energy in and out again. Now I get to begin the long, arduous task of disassembling the passenger side dashboard.
Tuesday, September 13, 2011
On the Road Again
All Willie Nelson references aside, the Z3 is back on the road. There's a lot to tell, and I'm sorry I haven't posted more as I was working, but as most of you know, I have a deadline that I had to make. This made for some very long days and nights in the garage. I'll touch on some of the highlights, good and bad.
The controller for the MasterFlux compressor comes as a circuit board with an aluminum heat sink anchored to one side and all the components open to the world on the other side. You don't have to be a computer expert to know that probably ought to be protected from the elements. I started looking for a project box big enough to put it in and would fit in the space I had picked out for it, but found none. It wasn't long before I realized I was going to have to build my own. Well, I figured that would be fun. My material of choice would be thin sheets of aluminum, but I don't have a press break, or access to one. There was no way I was going to be able to build a nice box out of metal with neat edges.
OK, that meant plastic was the material of choice. I found someone on eBay selling sheets of PVC plastic, so I ordered a 2'x4' sheet. I was able to cut it quite easily with a utility knife and a metal straight edge. It was clearly formed with a PVC foam-like material rather than the type used to cast PVC joints for plumbing. But on thing was certain, it would glue the same. I very carefully cut sheets the proper size, planning on two sheets per side, sandwiched together, with staggered edges so I would have more surface area to make sturdier lap joints at the corners.
My plan to build a box around the controller was going well. But then my dad had a great suggestion. He noticed that the heat sink is a bit larger with the edges sticking out beyond the edges of the circuit board, so he suggested making that one side of the box and simply enclose the circuit board. Brilliant! I was able to do just that and build a secure mounting system and put it exactly where I had hoped I would be able to. This had the added benefit of leaving the heat sink open to the outside air for cooling
Notice the fins of the heat sink facing the front of the car between the two battery packs. Right next to that, to the left, is a little project box that holds a large diode and two relays. The diode is to prevent current from the capacitors on the controller board from flowing back into the car's traction system should the voltage in traction system drop below the voltage stored in those capacitors. Apparently this was a common problem with the MasterFlux units that they've decided to overcome by recommending you buy an extra $25 part. The relays work like this: the on/off switch on the car's dashboard for the A/C system triggers one relay, which provides power to the fan mounted on the condenser at the front of the car, and to the second relay. That second relay simply makes a contact that will allow the 5V signal back to the controller turning it on.
(By the way, notice the nice new braided connectors between the batteries. Nice huh? )
All of this should work flawlessly. In theory. You see, I tested what I could before hooking everything up, but there was no way to test all of it as one system after it was hooked up, until all the batteries were in. Plus, I have no idea if it's even safe to run the compressor before the system has been evacuated of air and charged. In fact, I've been trying to reach Revolt Electric (the resellers of MasterFlux products) to ask them about this and a few other things but they have been, how shall I say, less than diligent about returning emails or phone calls. Part of being a reseller is living up to the responsibility of offering end user support, and they're falling short at the moment.
Tomorrow morning, I'm taking the car into a local BMW shop to have them evacuate the system and charge it. First, they'll put a vacuum on the hoses and pump all the air out. They'll leave it like that for a couple hours to be sure it holds the vacuum. If it does it's good to charge. At this point I have no idea if it will. I can't express how much I hope it does, but there's no telling. Since one of the new joints in the system had a brazed fitting, I think that one will be fine. The other one was still an accursed compression fitting. I give it a 50% chance of holding a vacuum.
If it holds up they'll charge it and I get to turn it on for the first time. I'm not worried about incorrect wiring and/or damage to the system, but there is the distinct possibility that it simply won't work for some reason which I can't conceive of at the moment. I'm about 90% sure that will go well. Whether I drive out of the shop with A/C tomorrow, only time will tell.
They are also going to align the front end to take out all the toe-in. I never had it re-aligned, so it will be interesting to see how much of an impact this has on energy consumption. Sadly I won't know right away because the new meter I put in isn't working.
Actually, the meter is not the problem, it's the original pre-scalar I was using with the Link-10 meter. When I put power to the system yesterday, I turned on the meter and started running through the various menu setting to set it up for the car. When it was done, it read that the system voltage was 68.8V. Wha... I double checked that I'd selected the 1/10 pre-scalar knowing full well that I'd never seen a 1/4.3 setting that would be necessary to see 68.8 Volts. Eventually I pulled the meter out of the console and actually measured the voltage on the wires coming from the pre-scalar. I found that it read 6.88 volts. Well how about that. Apparently while the car sat doing nothing over the past 4 months, the pre-scalar developed some sort of problem that renders it useless. I have no idea how, or why, but a replacement unit is $54. *Sigh* A new one is on the way.
Astute readers will have noticed in the picture of the motor bay that the big red slap switch I had in the prior builds is gone. "Where did it go" you ask? Well after I pulled it out to start the work in the area, I noticed something peculiar about one of the contacts on the positive terminal side. Take a look:
You can see in the top right side what the contact pads should look like. They are little silver pads soldered on the copper bar. However in the bottom frames, you can see that one of them has completely melted away. The bottom left picture is the bottom bar in the contact, and the bottom right picture is it's mate above. At some point, there was some serious arcing in there that, for all intents and purposes, destroyed this switch. Well there was no way I was going to put it back like that, and I see no reason in replacing it with a like one as there will now be the possibility of sending even more current through it. Nope, I need to find some other safety disconnect. But, that will have to wait for later.
I finally added an expansion tank for the coolant used to keep the Zilla cool. Finding a location for it was a challenge. The fact is, it's on the opposite side of the car from where the pump is. As a result, there are coolant hoses running all over the place. The underside of the car is, quite frankly, a bit embarrassing now. It's just too crowded with stuff and it all looks a bit thrown together. Such is life. The cooling system does seem to work great though.
Yesterday after putting everything back in and together, I was working near one of the batteries while touching the chassis of the car, and I grazed a battery and felt an unmistakable shock. What the! My mind raced. I got out my meter to check and sure enough, there was continuity between the chassis and the battery pack. I stood there cursing, wondering how the hell that had happened. I disconnected the positive most terminal and started looking to see what had happened. Eventually I isolated the problem to the motor. My first though was that as I'd lowered the battery pack on top of the motor, I must have crushed one of the lugs and it shorted out to the motor's housing.
There was no way around it, that pack was going to have to come out. Mind you, this is coming less than an hour after I'd put the final bolt in holding everything together. What a bitter pill that was. Rather than take the pack out as a whole, I decided the best thing would be to dis-assemble the first row of batteries and remove them so that I could see the terminals which are under them and if I'd crushed a lug.
What I found was no crushed lugs, but one was clearly wedged in there and under pressure. I as able to get to it and get it out. I found that the plastic boot on the terminal had what amounts to a pressure wound on top of it and was actually pierced, ever so slightly. The heat shrink tube underneath it looked intact, but I cut if off and could clearly see a hole you could fit a pencil lead through when I held it up to the light. There it was, that was what had been touching the chassis. I found a less risky path for that wire and bolted all the wires back in place. I checked and there was no continuity. Problem fixed. Whew!
This morning, I re-assembled the rest of the system, put power to the system, dropped the car to the ground and carefully drove out of the garage. I took off down the road cautiously and found that the car was driving perfectly. Furthermore, the wobble that was in the drive line before it went up on blocks was now completely gone. The Warp 11 motor was perfect again. Finally, on the road again.
Tomorrow is my appointment with the shop, which I'll report on. The rest of the week will be spent replacing that pre-scalar, and getting ready to trailer the car and tow it to Missouri for EVCCON. I am genuinely looking forward to that.
The controller for the MasterFlux compressor comes as a circuit board with an aluminum heat sink anchored to one side and all the components open to the world on the other side. You don't have to be a computer expert to know that probably ought to be protected from the elements. I started looking for a project box big enough to put it in and would fit in the space I had picked out for it, but found none. It wasn't long before I realized I was going to have to build my own. Well, I figured that would be fun. My material of choice would be thin sheets of aluminum, but I don't have a press break, or access to one. There was no way I was going to be able to build a nice box out of metal with neat edges.
OK, that meant plastic was the material of choice. I found someone on eBay selling sheets of PVC plastic, so I ordered a 2'x4' sheet. I was able to cut it quite easily with a utility knife and a metal straight edge. It was clearly formed with a PVC foam-like material rather than the type used to cast PVC joints for plumbing. But on thing was certain, it would glue the same. I very carefully cut sheets the proper size, planning on two sheets per side, sandwiched together, with staggered edges so I would have more surface area to make sturdier lap joints at the corners.
My plan to build a box around the controller was going well. But then my dad had a great suggestion. He noticed that the heat sink is a bit larger with the edges sticking out beyond the edges of the circuit board, so he suggested making that one side of the box and simply enclose the circuit board. Brilliant! I was able to do just that and build a secure mounting system and put it exactly where I had hoped I would be able to. This had the added benefit of leaving the heat sink open to the outside air for cooling
Notice the fins of the heat sink facing the front of the car between the two battery packs. Right next to that, to the left, is a little project box that holds a large diode and two relays. The diode is to prevent current from the capacitors on the controller board from flowing back into the car's traction system should the voltage in traction system drop below the voltage stored in those capacitors. Apparently this was a common problem with the MasterFlux units that they've decided to overcome by recommending you buy an extra $25 part. The relays work like this: the on/off switch on the car's dashboard for the A/C system triggers one relay, which provides power to the fan mounted on the condenser at the front of the car, and to the second relay. That second relay simply makes a contact that will allow the 5V signal back to the controller turning it on.
(By the way, notice the nice new braided connectors between the batteries. Nice huh? )
All of this should work flawlessly. In theory. You see, I tested what I could before hooking everything up, but there was no way to test all of it as one system after it was hooked up, until all the batteries were in. Plus, I have no idea if it's even safe to run the compressor before the system has been evacuated of air and charged. In fact, I've been trying to reach Revolt Electric (the resellers of MasterFlux products) to ask them about this and a few other things but they have been, how shall I say, less than diligent about returning emails or phone calls. Part of being a reseller is living up to the responsibility of offering end user support, and they're falling short at the moment.
Tomorrow morning, I'm taking the car into a local BMW shop to have them evacuate the system and charge it. First, they'll put a vacuum on the hoses and pump all the air out. They'll leave it like that for a couple hours to be sure it holds the vacuum. If it does it's good to charge. At this point I have no idea if it will. I can't express how much I hope it does, but there's no telling. Since one of the new joints in the system had a brazed fitting, I think that one will be fine. The other one was still an accursed compression fitting. I give it a 50% chance of holding a vacuum.
If it holds up they'll charge it and I get to turn it on for the first time. I'm not worried about incorrect wiring and/or damage to the system, but there is the distinct possibility that it simply won't work for some reason which I can't conceive of at the moment. I'm about 90% sure that will go well. Whether I drive out of the shop with A/C tomorrow, only time will tell.
They are also going to align the front end to take out all the toe-in. I never had it re-aligned, so it will be interesting to see how much of an impact this has on energy consumption. Sadly I won't know right away because the new meter I put in isn't working.
Actually, the meter is not the problem, it's the original pre-scalar I was using with the Link-10 meter. When I put power to the system yesterday, I turned on the meter and started running through the various menu setting to set it up for the car. When it was done, it read that the system voltage was 68.8V. Wha... I double checked that I'd selected the 1/10 pre-scalar knowing full well that I'd never seen a 1/4.3 setting that would be necessary to see 68.8 Volts. Eventually I pulled the meter out of the console and actually measured the voltage on the wires coming from the pre-scalar. I found that it read 6.88 volts. Well how about that. Apparently while the car sat doing nothing over the past 4 months, the pre-scalar developed some sort of problem that renders it useless. I have no idea how, or why, but a replacement unit is $54. *Sigh* A new one is on the way.
Astute readers will have noticed in the picture of the motor bay that the big red slap switch I had in the prior builds is gone. "Where did it go" you ask? Well after I pulled it out to start the work in the area, I noticed something peculiar about one of the contacts on the positive terminal side. Take a look:
You can see in the top right side what the contact pads should look like. They are little silver pads soldered on the copper bar. However in the bottom frames, you can see that one of them has completely melted away. The bottom left picture is the bottom bar in the contact, and the bottom right picture is it's mate above. At some point, there was some serious arcing in there that, for all intents and purposes, destroyed this switch. Well there was no way I was going to put it back like that, and I see no reason in replacing it with a like one as there will now be the possibility of sending even more current through it. Nope, I need to find some other safety disconnect. But, that will have to wait for later.
I finally added an expansion tank for the coolant used to keep the Zilla cool. Finding a location for it was a challenge. The fact is, it's on the opposite side of the car from where the pump is. As a result, there are coolant hoses running all over the place. The underside of the car is, quite frankly, a bit embarrassing now. It's just too crowded with stuff and it all looks a bit thrown together. Such is life. The cooling system does seem to work great though.
Yesterday after putting everything back in and together, I was working near one of the batteries while touching the chassis of the car, and I grazed a battery and felt an unmistakable shock. What the! My mind raced. I got out my meter to check and sure enough, there was continuity between the chassis and the battery pack. I stood there cursing, wondering how the hell that had happened. I disconnected the positive most terminal and started looking to see what had happened. Eventually I isolated the problem to the motor. My first though was that as I'd lowered the battery pack on top of the motor, I must have crushed one of the lugs and it shorted out to the motor's housing.
There was no way around it, that pack was going to have to come out. Mind you, this is coming less than an hour after I'd put the final bolt in holding everything together. What a bitter pill that was. Rather than take the pack out as a whole, I decided the best thing would be to dis-assemble the first row of batteries and remove them so that I could see the terminals which are under them and if I'd crushed a lug.
What I found was no crushed lugs, but one was clearly wedged in there and under pressure. I as able to get to it and get it out. I found that the plastic boot on the terminal had what amounts to a pressure wound on top of it and was actually pierced, ever so slightly. The heat shrink tube underneath it looked intact, but I cut if off and could clearly see a hole you could fit a pencil lead through when I held it up to the light. There it was, that was what had been touching the chassis. I found a less risky path for that wire and bolted all the wires back in place. I checked and there was no continuity. Problem fixed. Whew!
This morning, I re-assembled the rest of the system, put power to the system, dropped the car to the ground and carefully drove out of the garage. I took off down the road cautiously and found that the car was driving perfectly. Furthermore, the wobble that was in the drive line before it went up on blocks was now completely gone. The Warp 11 motor was perfect again. Finally, on the road again.
Tomorrow is my appointment with the shop, which I'll report on. The rest of the week will be spent replacing that pre-scalar, and getting ready to trailer the car and tow it to Missouri for EVCCON. I am genuinely looking forward to that.
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