Three Years On the Road

It was three years ago that the Z3 rolled out of the garage as a fully operational electric car.  It seems like an appropriate time to run through some statistics, as well as some of the hi-lights and some of the low points that the car and I have experienced in the last 1096 days (there was a leap year in there).

Number of miles driven: 14032
Number of charge cycles:         742
Average depth of discharge: 34.6%
Greatest depth of discharge*: 93%
Total kWh's used:                    4948
Total cost of charging the car at $0.075/kWh: $371.10
Total $ saved on not buying gas: $2001.62

Some of you may have noticed the new widget toward the bottom of the right hand column.  You may have even noticed that my numbers don't seem to match it.  I recently enrolled the car in the EVClub website, which is a nifty site whose intention is to track how many electric miles have been driven by it's members.  They also provide this nifty widget you can place on your website to keep everyone up to date on your EV miles.  Well when you enter the data for your car the first time, it asks for the number of electric miles you've driven so far and the price of gas.  I entered the current price, but really what it needed was the average price.  Thus the discrepancy.  I assure you, the total above is correct, but the one in the widget is close enough for government work.

The saga begins...

Two months after it's launch I noticed a vibration in the drive line   After disassembling the drive line  I was able to isolate it to the motor and discovered that the balancing putty had fallen off the armature.  After the manufacturers finish winding the armature, there is bound to be a slight imbalance in it.  To correct this, and save the motor's bearings, they bake some putty on one side to even things up.  Well mine fell off.  Netgain had it shipped back and repaired all at their expense.

By the time the car was back on the road, it was mid summer, and I realized that I've grown soft in my middle aged years.  A car with no AC was fine when I was 16 or 19.  Not when I was 45.  It sucked.  But I wasn't the only one suffering.  The Zilla controller was flashing warning lights at me, constantly warning me that it was in thermal cut back mode, dropping me down to 50% power.  Clearly I was going to have to get some cooling for me and the controller.  I couldn't address it then, and frankly stopped driving the car for the remainder of the summer.  A trip here or there at night, but that was it.

That following September, I blew up my charger.  A completely self inflicted wound, but this blog is all about honesty.  While charging the car, I was measuring one of the batteries.  The probe slipped and managed to touch part of the chassis and the battery terminal at the same time.  The Manzanita charger is not an isolated charger, meaning that it is grounded to the chassis.  Why, I have no idea.  But the consequence of this is if you do what I did, your charger blows up.  Fortunately, or unfortunately depending how you look at it, this is not an uncommon problem for people with Manzanita chargers, and Manzanita Micro has gotten rather good at fixing them with a quick turn-around time, and for a very reasonable cost.

The sharp minded among you will be saying to yourselves "Clearly he had something, probably a mounting bracket, too close to the terminal.  What a poor design.  What an idiot!!"  And you'd be right.  To address this, I could either spend a lot of time, effort and money to redesign the battery rack.  That, of course, would be the right thing to do.  OR, I could simply wrap all of those metal bits in rubber.  Which is what I did.  Only one degree up from "idiot" status, but it was a step in the right direction.

Nine months after the motor went back in, I notice the drive line wobbling again.  You guessed it, the putty fell off.  Again!  Netgain to the rescue one more time.

This time, since the car was apart, I decided I was going to fix the cooling issues.  I added a Masterflux AC system to the car, and a much larger radiator for the Zilla.  But as the car went back on the road in early September after that work, I didn't get the opportunity to really put the new cooling systems to the test.  That would have to wait for summer 2012.

Five months later (January 2012) I turn the charger on and hear a pop at the front of the car and the charger turns itself off.  To make a long story short, the car had a frame leak, meaning that you could measure the high voltage system on the chassis.  That is bad.  I was shocked and sickened to discover that the motor was once again the problem.  A build up of carbon dust from the degradation of the brushes resulted in a frame leak that I could not clear no matter how much air I pushed through the motor.  Plus, I found one of the brushes had been drilled by Warfield (the people that build the motor) and it had started to crumble. Who knows where that crumbling carbon went and lodged itself!  Netgain to the rescue once again.  George decided he'd had enough of this motor and sent me a brand new one.  I still can't sing his praises enough.  But I'm certain he curses when ever he hears my name.  George told me that he has my old motor in his garage and plans to put it in a Bricklin that he's been planning to build.  I really hope it treats him better than it did me.

The summer of 2012 came and went and the cooling systems I'd installed the previous year worked great.  I was cool, the Zilla was cool, we were both happy.

In July however, while checking to see if the batteries were still balanced at the bottom of the state of charge, I blew up my e-Xpert Pro meter.  Another self inflicted wound.  I didn't just blow it up, once I pulled it out of the dash, I realized it nearly caught fire.  For the price of one brand new meter, the car was whole again.

September rolled along, I went to charge the car one morning and the charger emitted a series of loud pops, a couple bright flashes, and then some smoke.  The charger made another trip back to the repair shop.  Talking to Rich Rudman, the owner of Manzanita Micro, he said he believed it was due to a faulty set of mosfets they had received some time back.  I got the charger back only to find that it wouldn't charge the car consistently.  The current output would jump all over the place.  So another trip back to Manzanita.

The last post I put up, from January, detailed a problem with more carbon build up in the motor.  That was easily resolved by re-positioning the inlet for the motors cooling fan, and with the aid of a leaf blower hooked up the cooling duct.  It blew every bit of carbon out of that motor.

There you have it.  Three years worth of EV adventures summed up in a few paragraphs.  I guess I focused primarily on the bad stuff.  But the fact is that the good stuff wasn't one or two events.  It was all the times between those problems.  Really, it's any time I get to drive the car.  I simply love it.  The 14,000+ miles of driving bliss far and away, out weigh the troubles I've had.

I've kept close track of the costs associated with building the car, and I can tell you that it cost me as much, if not a bit more than a new Nissan Leaf would have cost me.  Of course the Leaf wasn't available when I started building the car.  Nissan hadn't even announced it.  So would I swap the Z3 for a Leaf or another OEM electric car.  I have to say, there is something very appealing to off-loading maintenance and repairs to a warranty claim.  But missing the satisfaction of having built my own is too steep a price to pay.  Truth be told, I want one of each.  But that will have to wait.

Last week, I ordered some long over due parts for the car.  I'm going to be upgrading the suspension.  I will be able to bring the ride height back up to BMW's spec, and put on some slightly heavier springs to handle the extra 385 lbs the car gained.  Should be fun.

*That excludes the two times I took the cells down to 0% state of charge.  Once to bottom balance, and the second time to check if the cells were still balanced at the bottom after a year's use.  They were.

13,000 EV Miles

No doubt the 2 or 3 people that read this blog have long lost interest since I haven't posted anything for 3 1/2 months.  But as they say, no news is good news, and I would say that by and large, that applies here.  I pulled into the garage yesterday after running a quick errand (a Frosty for a sick child), and I took note of the odometer reading.  I delivered the Frosty and then entered the data in my spreadsheet and was surprised to see that the running total of EV miles I've driven added up to exactly 13,000.  Now the 3 year anniversary of the car hitting the road is in a month and 1/2 or so, but this seemed noteworthy enough that I thought I'd post an update of how things are going and include some numbers for those who enjoy statistics.

Keen readers will remember the episode I went through, just about a year ago, with a high voltage leak to the chassis, which I traced back to a frame leak through the motor and ultimately resulted in getting a new motor from Netgain.  George Hamstra was simply sick of repairing it and sending it back to me.  On a side note, George told me he has that motor in his garage and intends to put it in his Bricklin conversion.  I hope it does well for him.  At any rate, in addition to putting the new motor in, George also sent me some new brushes to try out, ones he felt would produce less carbon dust and so were better suited for my application.  He sent me (at his expense mind you) some Helwig Red Top brushes that are made of a harder compound than the standard brushes the Netgain motors come with.

You have to understand, Netgain Motors was born out of the EV drag racing community.  The earlier drag racers kept burning up their GE motors.  George and others saw different opportunities to improve the motors here and there.  They were working with Warfield Electric on building motors that incorporated their changes.  Before long they had a completely new beast on their hands and decided to start selling them.  The brushes they chose were of a softer carbon compound, ideal for pushing high current to the armature   Under drag racing conditions, the motor would generally fail for some other reason long before the brushes did.  But under low current applications, like driving to the store for milk and such, the brushes tended to wear out much faster and give off a lot of carbon dust.  The Helwig brushes have worked out so well for them that they've made them available on new motors.

Understanding that, we get back to my car and the unexpected change I noticed after I installed the new motor with the new Helwig brushes.  Suddenly, the car was more efficient.  About 14% more efficient to be precise.  Jack Rickard of EVTV ran experiments with an old WarP 9 motor he had at his shop, and found the same improvement.  Well, a great deal of time has passed, and I've put many more miles on the car, 4797 to be precise.  I thought I'd take a look at the numbers to see if the increase in efficiency has held true.  The thing is, I realized that I'd been doing the math wrong.  Well, the truth is, I knew I was doing it wrong, but I was too lazy to fix it, thinking the difference would be minimal.  To sum up, I was taking all the trips I made, and averaging the Watt hours per mile used.  The trouble is, the 275 Watt hours per mile used on a 35 mile trip was being averaged equally with the 378 Watt hours per mile on a 4 mile trip.  Anyone can see, those numbers needed to be weighted differently since the distance was different.  The solution is easy: add up all the miles driven and divide it by the sum of kilowatt/hours used.

What did we get?  As I mentioned, I've driven 4797 miles since the brush replacement, and I've used a total of 1526.46 Kilowatt/hours.  That works out to 318 Watt hours per mile.  In comparison, I grabbed a 4804 mile sample of data from before the brush swap and noted that I'd used 1779.72 Kilowatt/hours, which works out to 370 Watt hours per mile.  So does the 14% efficiency gain still hold water?  370 - 14%(51.8) = 318.2.  Apparently so.  I knew the way I was calculating the data before wasn't going to be wildly inaccurate, or even mildly for that matter.  But it's encouraging to see that numbers still hold to be true.

Moving on.  A couple weeks ago I plugged the car in, turned on the charger and heard a familiar "pop" come from the front of the car.  I recognized it immediately as the same "pop" I'd heard before when the motor had become caked with carbon dust and there was a mini flash over in the motor.  What the...?!!!  The only way this would happen was if the carbon dust given off by the brushes wasn't being blown out.  Since the Manzanita charger is grounded to the chassis, when you turn on the charger, if it senses a path from the chassis to the battery pack, it will either throw the circuit breaker in the charger itself, or blow up.  I've had it do both.  For the gory details of each, feel free to look further back in the blog.  Suffice it to say, you don't want to accidentally touch a battery terminal and the chassis with a multi-meter probe at the same time when you're charging.  Anyway, clearly I had a build up of carbon again!  How could this happen?  I've got a fan forcing air into the motor for chrissake! It should be blowing all that dust out.

I checked the fan, and it was running, but the output was very low.  I looked at the filter and found that it was caked with dirt.  Ahhhh.  I'd cleaned it about 6 months earlier, but clearly there's a problem.  Well the problem is really quite simple.  Having no way to locate the fan and the filter higher up in the motor compartment, I mounted it on a tray right next to the motor.  Meaning that the fan and the filter are about 9" off the ground, right were the dirtiest air is.  You may have noticed that every manufacturer locates the air intake for their cars as high up in the engine compartment as possible.  I'm thinking that may be intentional.  I took the filter off and the flow of air was much better, like I expected it to be.

So now I'm left with two problems.  First, the motor is full of dust and I need to blow it out. Second, I need to figure out what to do about this filter location; clearly where it's at is not the best place for it.  Last time I had a dust problem with the motor, I used compressed air to blow it out.  That worked pretty well as a huge plume of dust came out when I aimed the air gun into it.  The problem is, I have to take the motor's shroud off, and to do that I have to take out the batteries over the motor and to do that I have to ...  you get the picture.  Curse the idiot that designed this!!!  But then I had a flash of inspiration.  What If I simply hook up my leaf blower to the inlet hose, the one that runs from the fan to the motor.  Leaf blowers put out a crazy amount of air.  Oh, now this will be good.  Or at least fun.

It wasn't easy, but I was able to get to the inlet hose and basically taped the end of my leaf blower to it using my favorite tape in the world, gaffer's tape.  It's basically black duct tape, but easier to tear.  I had my daughter sit in the car and rev the motor up to about 3500 RPM, and I turned the blower on.  I was very pleased to see a plume of black dust come out the back of the motor (and also a bit disturbed).  I let it run this way for three or four minutes until I was confident it had expelled all the free carbon it could.  The great thing was, I could put my hand at the back of the motor and feel a tremendous volume of air coming out.  I started to wonder, could I some how use this leaf blower as my motor fan?  Apart from it being impractical, it would make the Z3 the noisiest EV on the road, ever.  No, what I really need to do is sort out the filter location problem.

With the fan located low like it was, it's collecting dust at a much faster rate, and ultimately choking the motor.  I looked, thought, measured, looked, thought some more and came up with nothing.  There is simply nowhere else to locate that filter.  Then I had a thought.  what if I eliminated the filter completely?  Stick with me for a moment.  The Netgain motors come with a screen covering the front bell housing, and the brushes.  People run them like this all the time.  The problem is some dirt and sand will inevitably get in and get on the armature and brushes cause them to wear prematurely.  OK, so that's the trade off.  But now, what if the inlet for that air came from a place that was less prone to see dirt and sand in the first place?  After all, the front of the motor sits right where you would expect most of the dust and grime to be, so if I could find a place for the inlet that would provide cleaner air than that, I should be good.  What I found was that there was a way to run a 3" hose from the fan inlet up in front of the firewall and just behind the large battery pack that's over the motor.  It's shielded from the main airflow when the car is moving down the road, yet it's got an open area large enough that it can easily get all the air it needs.  I checked and the output of the fan was terrific.  As far as I'm concerned, problem solved.  It's true that a bit of dirt may be blown into the motor, but I think this is a far better solution than cleaning the filter weekly to ensure good airflow through the motor.

The truth is, I'd love to get a fan that would push more air into the motor.  The one I have pushes 120 CFM.  George even said that's likely too low.  The problem again is one of space.  The fans I've found that push more air won't fit in the space I have.  I keep an open eye out for one, from time to time I comb through the interwebs looking for a suitable candidate.  So far, no luck.

That's all for now, but check back in early March on the car's 3rd anniversary as I'll post some more stats.

Efficiency I Can't Quite Explain

With the exception of the few months the Z3 has been off the road for repairs or upgrades, I've been driving the car for just over 26 months.  During that time, I've kept detailed records of every charge/discharge cycle of the batteries.  Every time I plug in, I note the mileage on the odometer, and the number of amp hours I've drawn out of the pack.  I then take that data and plug it into a spreadsheet that calculates a number of things for me, including how much money I've saved because I wasn't burning gas, how much the electricity I'm using is costing me, and most interestingly, how many Watt-hours per mile the car is using.

I've reported in the past the the car averages about 320 Watt-hours per mile on surface streets.  That's the number I've used to calculate the range of the car: 19,400 Wh / 320 Wh = 60.625.  This is why I've always stated the car has a 60 mile range.  And I've proved that out once, driving 62 miles on a charge once, in preparation for doing a bottom balance on the batteries.

Of course, once I go on the freeway traveling between 65 and 70 mph, that 320 Watt-hours per mile begins to look like a distant dream.  The aerodynamic drag on the car causes energy consumption to quickly rise to around 420 Watt-hours per mile at 65 miles an hour.  That meant that my round trip to work, a 23 mile journey, which includes 7 miles of surface streets and 16 miles of freeway, averaged between 370 and 380 Watt-hours per mile.  I've made this trip a few hundred times, I know the numbers.

It's no secret that I've had a few problems with the motor in the car.  The balancing putty has come off for a some inexplicable reason, twice.  Just recently it developed a short to the case that no amount of air blown through its guts could resolve.  George Hamstra at Netgain has been a champion through all of this and ultimately had a new motor sent to me.  In addition, we swapped out the brushes from the standard H-49 brushes used for high current applications like drag racing, to H-60 brushes which are better suited for street use.  A cool feature on Helwig H-60 brushes is the split, Red Top design, which helps to ensure better contact on the commutator.

At any rate, I got the new brushes seated in the motor properly, put the car back together and launched it back onto the streets about 3 weeks ago.  The car is my daily driver, so once I began driving it to work and other places, and recording the energy consumption, I was a bit surprised to notice it was more efficient.  At first I thought it was maybe just an anomaly, but it's clear something has caused the car to make much better use of the energy in the batteries.  My round trips to work are now averaging about 280 Watt-hours per mile.  Compare that to the older 370!  That's more than a 25% improvement in efficiency!  I made one trip where the average dropped to 266.

Today I took a bit of a longer trip out to Scottsdale.  A total of 38 miles, with 30 of those miles on the freeway, traveling around 70 mph.  The average consumption for the entire trip was 274 Watt-hours per mile.  In the past, I would have estimated this trip to be a 400+ Watt-hour per mile trip.  But that's not all!  During the entire trip, I had the AC system on (which draws about 9 amps) and of course, I've configured the power steering pump to run all the time now adding another 2 amp continuous draw.  BTW, the change to the power steering is interesting, but that's another post.  So there are more parasitic loads, yet, efficiency is up.

The one thing I haven't done yet is to see what average I would get if I traveled at 40 or 45 mph.   There's no reason to think the gain in efficiency that I'm seeing wouldn't appear there as well, but I simply don't have those numbers yet.

It seems like an obvious conclusion to draw that the increase in efficiency can be attributed to the new motor, or brushes, or a combination of them both.  But I really can't say that with certainty.  Perhaps I'd made some error when installing the drive line in the past which caused some binding or friction that I simply wasn't aware of.  I kind of doubt that, but who knows?  There's no question I've gotten better at disassembling the drive line of the car, but there really isn't much room for error here.  I have no reason to doubt the numbers the meter is giving me; after all, it's the same meeter with the same set up I was using before the motor swap.

What ever the cause, the car does seem to be more efficient.  At an average draw of 280 Watt-hours per mile, it's gone from a 60 mile range to nearly a 70 mile range.  I'll take it.

Update 5/20/2012:

I've continued to see the gains in efficiency I detailed above, but I've realized I've let myself fall victim to insidious creature that is over optimism.  I've always maintained that the Z3 had a 60 mile range.  That was based on the fact that it consumed about 320 - 330 Watt-hours per mile when driving at ~45 mph in normal traffic.  What I really hadn't done is take an average over multiple trips to get a more balanced number, a real world number you can take to the bank.  Well since I've seen this improvement in efficiency, I've gone back  to my spreadsheet to see if I could mine some more useful, accurate data from the numbers.  Here's how it works out...

Since the car was put on the road, up until the motor/brush replacement, it has averaged 376 Watt hours per mile.  That is the real world average.  Sure there were many trips that were better, but there were also many that were worse.  I can't get out of my neighborhood without consuming something like 480 Watt-hours per mile.  It's all about stopping and starting.  With no regenerative braking, stop signs and stop lights really affect your range.  The more of them per mile, the worse your range.  Well, there's 6 stop signs on one of the routes it takes to get from my house to the main streets, so you can imagine what that does to energy consumption.

The average after the motor/brush swap has dropped to 321 Watt-hours per mile.  Compare that to the old 376, and you note a 14.7% improvement.  That is huge!  Interestingly, and I've mentioned this above, virtually all of the trips I've made in the car since putting it back on the road have been on the freeway at 65 - 70 mph.  Meaning, that as more trips on surface streets are recorded I expect that 321 number to drop even further.

The bottom line is that I've been misrepresenting what the car's range really is by skewing the data toward the happier, more optimistic lower numbers.  Not intentionally or maliciously mind you.  The old average was 51.6, the average now seems to be 60.4.  A painful thing to admit, but there you have it.  Just as I could have easily squeezed 60 miles out of the car before, sticking to surface streets and avoiding stops, I expect I could squeeze 70 miles out of it now, doing the same. 

I've brought all this to Jack Rickard's attention at EVTV, and just like me, he was skeptical and ultimately amazed.  He's been doing some tests swapping out the original H49 brushes for the split, Red Top H60's and he's finding the same results.  I have a feeling this is going to be a hot topic in the EV community for a while.

What An Ordeal

The few of you who read this blog have probably wondered what's been going on with the Z3.  When I last left you, I'd received the new motor, had put the new split top, harder brushes in and was seating them by running the motor off of a 12V battery.  Well, quite a lot has happened, and frankly, it wasn't all good.  So sit back and enjoy the saga.

Once I installed the new brushes and turned the motor on, it made a hell of a racket for the first few hours.  I remember seeing a video John Allen had made when he was breaking in new brushes for his Warp 9, and I was struck by how loud it was, so I wasn't too surprised when mine made similar noises.  I ran the motor for 100 hours and at the end, it sounded as smooth as silk.  Job done!

I mounted the motor up to the transmission and tightened up all the bolts and called it a day, planning to reinstall the motor/transmission back into the car the next day.  During the night, I realized I'd done something kind of stupid.  The manual for the car states that you should put a little grease on the input shaft before you mate it up to the motor.  It already had a film of grease on it, but I thought more is better.  When thinking about it that evening, I realized that I had cleaned off a little grease I'd found on the flywheel.  It was in a pattern that looked like it had been thrown off the shaft.  It was at that point I realized more is not better, and I'd set myself up for a greasy, slip prone clutch.  So I took the tranny off the motor, cleaned the shaft of excess grease and mounted it back up.  It only took 45 minutes or so, so it wasn't that bad.  I'm telling this story so that if anyone out there reading this can learn a lesson from my stupidity, then I've served some purpose on this planet.

Moving on.  The motor/transmission assembly went in to the car later that day without a hitch, and thanks to my dad who came out to help me.  I mounted up the drive line and started the process of re-assembling the car.  It went quite smooth really.   I was making one of the last battery connections when I leaned my elbow on the chassis, and it felt like I got stabbed or cut.  I remember thinking that I didn't remember the bolt I leaned on being particularly sharp.  I touched it again and realized that I didn't get stabbed, I got shocked.  That's right my friends, the leak, which I was trying to get rid of, the one for which I'd been sent a replacement motor, was not gone.

Talk about a kick in the teeth.  I started testing and dis-assembling everything and came to the conclusion that, once again, the source of the leak was in the motor.  How could this be?!!!   I was absolutely gutted and just walked away from the car for what ended up being the whole weekend while I thought about what to do.

I decided what I had to do was figure out, definitively if it was the motor or something else.  I decided the best way to do that was to assemble all of the components completely, but leave the motor out of the assembly process.  In place of the motor, I simply ran a cable from the Motor + terminal on the controller to the Motor - terminal.  This was simply to replicate the existence of "something" in the system at that position in the circuit.  Once it was all back together (minus a few batteries) I found that there was no leak. I added the motor back in, the leak appeared.

I thought perhaps breaking the brushes in had created enough dust to cause the problem, so I decided to blow it out with compressed air.  While some dust did come out, I could still measure the HV pack voltage on the chassis.  Ghaaaa!!

It was time to contact George again.  I can't express to you how much I did not want to darken his inbox with bad news again.  George asked if I would send him and Tom Brunka of Helwig Carbon Brushes a picture of one of the brushes that I broke in.  He wanted a close up of the face and shot of the profile.  Puzzled, and unsure of how that would help, I obliged and sent off the photos.  Tom got back and said that the brushes looked like they were broken in perfectly, so that was good.  But then he apparently noticed something else, and that was the model number printed on the brush indicated it was for a 9" motor.

The pieces started falling into place for George at that point.  The commutator on a 9" motor has a smaller circumference than that of an 11" motor.  That means that the brushes for a 9" motor would be made with a smaller arc to the face.  Aside for that, they are identical in function, composition and structure.  But what that meant was that rather than the brush's surface resting with more or less complete contact on the commutator, it was riding on the very edges.  That explained why they were so loud when I first put them in.  Truthfully, at that time, I even wondered if I might have been sent brushes for a 9" motor, but it was just a passing thought.

So, through an innocent mistake, George had sent me the wrong brushes.  He mentioned that it really was no problem to use them now that they were seated so well, and I would have had to wait another 2 weeks to get 11" brushes anyway.  I was fine with keeping these.  Anyway, because the brushes weren't contoured correctly for the 11" motor, that meant that a bit more material had to wear off of them than would have normally happened.  Couple that with the fact that when running off a 12V battery, the motor doesn't spin fast enough to create enough airflow to vent the dust that does come off the brushes, and you have a recipe for developing and internal path to ground.

I went back and measured the resistance of the path from the motor terminal to the chassis and found that it was .880 mega Ohms.  Don't ask me why I didn't measure that after I blew the motor out the first time, but I didn't think to.  I saw that I could measure voltage on the chassis and felt that was enough of a problem that I didn't think to measure resistance.  But what I found was that after I had blown it out, it had made a difference.  .880 mega Ohms can only pass 0.13 milliamps at 160 volts.  I could touch the terminal of the battery and the chassis and felt nothing.

George added that once I got the motor back on the road and spun it up to 3000 RPM, it would blow the rest of that dust out.  he also mentioned that Warfield Electric consider a leak to chassis acceptable as long as it won't light up a light bulb.  Well, .13 milliamps isn't enough to light a light bulb, and it's also not enough to cause my charger to complain.

Today I got everything back together, tested the systems, and flipped the charger on with fingers crossed.  It came right on and dutifully charged the batteries back up to full.  All systems go!  I took the car down from the jack stands drove it out of the garage and put 20 miles on it this afternoon.  It seemed like everyday since the car has been out of commission, I came across either a Nissan Leaf, or a Chevy Volt, while out driving and I would just grumble in envy.  Today I saw Leaf  while I was driving the Z3, and I simply felt joy.

Seating New Brushes

You're probably familiar with the problem I've been facing recently regarding the leak to chassis ground through the motor.  It's proven to be a very strange problem. I made a quick video to demonstrate what I'm seeing, take a look.

A leak at 635 Ohms and 160 volts equates to 252 milliamps.  The 436 Ohms I read the following day would produce a current leak of 367 milliamps.  I've seen the reading as high as 1180 Ohms, and as low as 350 Ohms.  This sort of leak is most often caused by the accumulation of dust in the motor.  I've blown enough air through the motor that if that were indeed the problem, it should have fixed it.  But as you all know it hasn't, so George Hamstra has decided he's seen me suffer enough at the hands of this motor, so he's sent me a new one.

 Since that picture was taken, I've pulled the clutch assembly, flywheel, adaptor plate and taper-lock hub assembly off the old motor with the help of my friend Dave from Tucson.  However, I haven't put it on the new motor yet.  In email exchanges with George, I mentioned that I would be sending back the $320 brushes he sent me (at his expense) to try to resolve the problem with the original motor.  But he replied saying instead that I should put them in the new motor.  He believed that the brushes in the new motor were likely brushes better suited for racing.  I peered in the motor and found they were the Helwig Redtop brushes, but when I compared them to the ones George had sent me I could see a marked difference.  They were a bit shorter, but much darker in color.

So at George's recommendation, I swapped them out.  But that means I need to seat, or bed in the new brushes before I put the motor in the car.  Essentially, you strap the motor down, and connect it to a 12v battery and let it spin for 100+ hours.  It sounds easy enough, but actually getting it done required some effort.

First I needed a 12 battery.  I don't have one laying around, so I went to the local Costco and bought the cheapest 12v deep cycle battery they had for about $80.  I was under the impression that the motor would draw about 3 to 5 amps, once it had spun up and was running smoothly.  So I thought my little 0-12 amp battery charger could keep up.  Well, that was off by a factor of 10.  It actually draws about 45 amps at start up and settles in to a constant draw of about 35 amps.  Fortunately a friend at work was kind enough to lend me his heavy duty charger that can put out up to 200 amps for starting a car, or as much as 40 amps for charging the battery.  Perfect!  Here's how the assembly looks.

At the top right, we have Fred's big charger.  Below and to the right, is the 12V battery.  I have both the cables to the motor hooked up to it, as well as the cables from the charger.  Notice on the negative line running to the motor is a big switch; a nice way of turning the motor on and off.  My meter is sitting on top of the battery with the probes connected to the terminals.  In the morning, I turn the motor on.  When I see the battery hit about 11.00 volts, I turn the charger on.  It operates by timer, so I set it for 2 hours.   It immediately pushes the voltage up to about 12.8 and puts out about 43 amps.  The motor is drawing about 35, so it's a net of about 8 amps going to the battery.  Over that two hours time, the voltage on the battery rises to about 13.5.  By the time the battery hits 13.7, the charger is putting about about 36 amps, or one amp more than the motor draws.  So I turn the charger off and let it rest.  (I don't want to burn it up.)  When the battery gets back down to 11V, the charger goes back on.  I'm on day 4 of the break in, and it's been running about 50 hours.  Since the charger is on a timer, I can't run the system at night.

When the brushes have had enough time to seat, I'll re-assemble the adaptor plate and clutch, then work to getting it back in the car.

A Great Video 

On an unrelated note, a PBS station back East, WSIU, has published a story about last Septembers EVCCON and EVTV.  The story is quite well done.  It explains what the movement is about, why people are doing it for themselves and why Jack and Brian are producing the weekly EVTV show.  It's about 1/2 hour long, and it's well worth watching.  While the Z3 is not featured in the video, you can see it in the background on a few shots.  Take a look:

A Missed Anniversary and Motor Drama

Some of you may be distantly aware that March 2nd marked the Z3's second year on the road.  Unfortunately, as you know, it's not actually on the road at this time.  It has once again, fallen victim to a motor problem.  Of the 12 month span starting last March until now, the car has been on the road for only 6 1/2 of those months.  Not all that time was to repair motor problems.  Last July, August and beginning of September was spent adding the MasterFlux AC system and getting the car ready for EVCCON.  Never the less, it has has not been as trouble free as I would have liked.  But I remain optimistic that those types of problems may soon be behind me and I'll be in for some extended trouble free motoring.

So let's move on with what's been happening the past couple weeks.  To catch everyone up to date that hasn't read the last couple posts, the car developed a leak to ground.  That means that I could measure the high voltage on the frame of the car.  That poses a few problems, one being the threat of being shocked, another being the threat of arcing and potential fire under the right circumstances, and last, the charger wouldn't stay on.  The charger is grounded to the chassis of the car, so when it sensed the high voltage on the chassis, it simply shuts itself off for protection. 

I'd methodically tracked the problem down to the motor, finding that there was a leak from the terminals where the high voltage is sent into the motor, to the case itself.  This is not supposed to happen, but it can if there's been a build up of dust inside the motor caused by the wear of the brushes.  Most recommend blowing out the motor out with compressed air, which I did, repeatedly.  In the mean time, I contacted George Hamstra from Netgain to find out if there was a preferred method for cleaning the motor more thoroughly.  Compressed air is pretty much it.  He reasoned that I must have brushes in the car that are better suited for racing and tend to dust quite a bit.  So he took it upon himself to send me, at his expense!, a set of $320 replacement brushes.  Not just any brushes, mind you, but Helwig split top brushes, pretty much the best money can buy.

The top two brushes are tied together on one connecting wire.  That is one of the older sets.  Presumably, they were the same size as the new Helwig brush at the bottom, but look how much they've worn after only 9,000 miles.  Notice too how the old brush closest to the new one is shorter than the top brush.  Curiously, this was the case with each pair.  The brush that was in the bracket closest to the front of the motor was warn by as much as 1/8th of an inch more than the back brush.  I don't know if that means anything, but it certainly happened.


I've mentioned that George is tired of seeing me suffer through problems with the motor.  He also offered at that time to simply replace the motor, but I asked him to hold off to see if more cleaning and the new brushes made a difference.  The new brushes arrived on the 1st of March, but I didn't get a chance to work on the car until the 4th.  I was able to pull 3 sets of the old brushes out with no difficulty.  But on the 4th set, I was able to get one brush out OK, but the space was so tight and constrained, I simply could not get the last brush out.  After laboring over it for a few hours, and coming to terms with it for another the next 24 hours, I finally came to the decision that I was going to have to pull the motor and transmission out of the car.  Believe me, that was something I did NOT want to do.

My dad was kind enough to come over and help me out.  It took us about 4 hours, but we got everything unhooked, the motor free and then we were able to drop it out of the car.  I've lent my lift to a friend, so I didn't have that, but it's OK, because this time I was determined to drop the motor out instead of lift it out.  with the cunning use of the floor jack, several 2x4s, levers and muscle power, we were able to do it.  That gave me access to the last brush, and I carefully pulled it out.  It was at that point that I looked at the brush I just pulled and saw something truly astounding.  Take a look:

Yes, what you see there are 3 holes drilled into the top of the brush, and a chunk of the brush missing!  Where it went, I have no idea.  I looked around everywhere, but could not find the piece or pieces of carbon laying about.  As it was the last brush I pulled, it should have come out with the brush, but it didn't.  It got me wondering if perhaps it had come off and become wedged somewhere inside the motor, causing the short.  It seems unlikely, but I have no way of knowing without disassembling the motor.

With the brushes out, I took the opportunity to blow more air through the motor.  A lot more air.  The air gun I had been using works fine, but the nozzle is fixed and short.  I bought an air gun with an 8" flexible nozzle that I was able to carefully insert into the motor and spray in harder to reach areas. 

I sprayed compressed air until I saw, or could smell no more dust.  Believe it or not, that dust has a funny smell (even though I was wearing a mask).  I put the new brushes back in carefully, and took another reading with the Ohm meter.  To my astonishment, the leak was actually a bit worse.  I hooked up a 12v battery to the motor with a switch in line so that I could run the motor for a bit and try blowing more air while the motor was moving.  Had to be careful not to stick the nozzle anywhere in the motor or near the brush assembly.  4 or 5 more tanks of air and no dust coming out.  At this point, the motor is as dust free as I can get it without taking it apart. 

After all that, the leak persists.  At it's worse I measured the resistance between the S1 terminal and the case at 508 Ohms.  That's enough to pass 320 milliamps.  Again, not a lot, but certainly enough to feel, and enough to render the charger useless. 

I contacted George with the story, telling him the results of my efforts, and sending him the picture of the brush.  At this point I'm faced with either taking the motor apart and trying to clean it further, or getting a new one.  George was absolutely dumbfounded when he saw that picture.  He said that it looked like someone had tried to make a Brush Wear Indicator, but he couldn't figure out why they drilled three holes, or worse yet, why they left that brush in the motor.  He was pissed, and justifiably so.  He's paid to have this motor repaired twice and the second time he told them to pay particular attention to it so that it was done to the highest standard possible.  Clearly, that didn't happen. 

Fed up with the whole thing, George is sending me a new motor.  I must say, that I have very mixed feelings about this.  On one hand, I'm thrilled to be getting a motor that will hopefully have none of the flaws that have plagued this motor from it's first day.  On the other hand, it just eats me up that this whole fiasco has cost George so much.  Shipping to Illinois and back, twice, two rebuilds of the motor, and finally a whole new motor plus the shipping for that from Illinois.  Dreadful!  I had hoped to be one George's success stories. 

While all of this is going on, I am planning a couple minor enhancements.  I bought a voltage meter/display from Lightobject that can be programmed to cut a relay at a specific voltage.  I'm thinking that I'd like to add that to the car as a safety backup in case the charger doesn't cut off in time.  If this device sees the voltage rise to the level I've defined, it would trigger a relay that would simply cut power to the charger, protecting the batteries.  Stay tuned. 

Brushes and Carbon Dust

While at EVCCON 2011 I had the good fortune to catch a talk given by Tom Brunka from the Helwig Brush Company.  Tom went into great detail about how brushes for DC motors work, the different properties they can posses depending on the way they are manufactured, and the care of brushes and motors.  On the face of it, it seems this talk would be astoundingly boring, and in fact I think Jack Rickard scheduled it for the last talk of the conference precisely because he figured it would be lightly attended and would be in no danger of running long and interfering with the events planned for later that day.  As it turned out, it was a truly fascinating talk and it went much longer than expected due to the fact that attendees started asking questions as soon as Tom finished and simply wouldn't let up.  Eventually Jack had to put a halt to the exchange so that we could all go outside and race our cars.  What a great time that was.

One of the things that Tom mentioned is that brushes will wear and break in at one rate, but once they are bedded in, they will wear at a completely different rate.  The wear of the break-in rate is much higher than standard wear rate.  But the interesting thing is, if you disturb the brushes, i.e. remove and replace them, lift them out of their holder, nudge them, breath on them, or even look at them askance, they will begin to wear at the break-in rate again.  This level of wear has a couple of effects.  First and perhaps most obvious, your brushes wear out faster.  As a direct result of that faster wear rate you encounter the second issue, which is an accumulation of the dust that wore off the brushes on the inside of the motor.  If you have the motor ventilated with forced air, some of that dust will be carried out of the motor's vents.  But not all of it.

Such is what has happened with my motor.  Faithful readers will remember that I have had the motor out of the car a couple of times due to a strange phenomenon where the balancing putty fell off the armature.  On both occasions George Hamstra at Netgain motors, shipped the motor back to Warfield electric and had them repair it.  In order to do so, they had to dis-assemble it.  Now I didn't look at the brushes when the motor came home from the first repair so I don't know if new brushes were installed, but I did look at them the second time and they were the same brushes that were in the motor when it left.  How do I know?  Well new brushes are not contoured to fit perfectly against the armature when they are new.  As I said earlier, they must be worn, or bedded in and this can take up to 5000 miles to do.  But since the brushes had necessarily been removed during the motor's repair, that meant they were going to go through another instance of excessive wear and re-bedding; meaning more dust.

What does this have to do with my current situation?  Well, all that carbon dust is conductive.  After all, it's through that very carbon that the current is pushed to the armature of the motor.  I have a fan on the motor, pushing 110 CFM of air through it and likely carrying out a good percentage of the carbon dust along with the heat it's meant to blow out.  But clearly not all the dust is going out.  Somewhere within the motor, some dust has piled up and allowed a small path for current to flow from the high voltage fields to the case.  That's not good but apparently not unheard of.  Normally, you simply blow the motor out with compressed air and the problem leaves the motor in a plume of black dust.

So, I charged up my compressor, took the shroud for the fan off the front of the motor and started blowing.  There was plenty of dust.  More than I expected.  I thought this was great, it meant I likely fixed the problem.  Unfortunately not.  The problem is that in order to get all the necessary components in the car for it to function, Or simply because I'm very bad at designing things, all the components are crammed in there so tight it's difficult for me to get a nozzle in there to blow out every nook and cranny.  But my blow gun's nozzle is right at the end of the trigger limiting where I can really point it.

I've exchanged some emails with George and he suspects that the brushes in the motor right now are a high performance brush called H49 which do great for racing, but tend to dust a lot.  He thinks that the H60 brushes, which are a harder, street grade brush would be better suited for my build with the added benefit that they will produce less dust.  He's decided to send me a set of these at no expense.  Well, no expense to me.  They normally run over $300 a set and George is picking up the bill.  To say that George is fed up with my motor is an understatement.  He's stated that he will not RMA the motor again.  Meaning, if it ever has another problem, he intends to replace it.  Believe me when I say that it's very comforting knowing that he will stand behind the motor so resolutely.  For now, I just don't see a reason to do that, and here's why.

The new brushes will arrive early next week.  I've ordered a blow gun for my compressor with a 12" flexible hose which will allow me to better squirt air in all the nooks and crannies inside the motor.  I'll remove the old brushes, and push 8 or 10 tanks of air through the motor, then replace the brushes.  If all goes well, I should see the short go away.  Depending on the temperature, and consequently the time of day, the resistance of that short fluctuates between 1.18K Ohms, and .85K Ohms.  That means a potential leak of current in the range of 135 to 188 milliamps.  If I can't resolve the short and I have to take the motor out of the car then I'll have to decide whether I want to try to disassemble it to clean it, or simply give George the go-ahead to send out a replacement.  I really don't want to do that though.

Battling a Frame Leak

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.

Motor Drama

I have refrained from posting about this for a variety of reasons, but mostly because I wanted to write it up in one story once I knew the whole story.  While there's no "happily ever after" quite yet, but I'm optimistic that there will be.

Sometime this last February I noticed a disturbing, but familiar feeling in the car's drive line; vibration.  It started small, and I kept telling myself it was my imagination.  But two weeks or so later, there was no denying it, the wobble that forced me to pull the motor a year ago was back.  I was, and remain absolutely perplexed as to how this happened.  I took the cooling shroud off the front and, sure enough, the balancing putty fell out the front.

I contacted George Hamstra and Netgain and told him what had happened.  He was more shocked than I was.  He explained that only one other motor had ever had the balancing putty come off, and that was because the owner had spun the motor up North of 9000 RPM.  He went on to say that they had never seen it happen twice!  Well, my motor has never seen anything over 5000 rpm, so that wasn't it.  I also have cooling air forced into it constantly, so heat shouldn't have been a factor.

George talked with the folks at Warfield electric, brainstorming on what the possible cause might be.  They were able to rule out the RPM and temperature possibility right away.  The wondered if perhaps they had a bad batch of putty, but reasoned if that were the case, then they would be seeing failures on multiple motors since a single batch will be used on several motors.  Well that wasn't happening.  They speculated that perhaps it had been applied poorly.  Who's to say, but it seems unlikely that it was applied poorly twice on the same motor.

George joked that "It's just you Tim!"  Truthfully, I don't know that he's wrong.  I explained how I had the motor mounted up in as much detail as I could.  The motor was tied down to the sub-frame of the chassis with a rubber pad under it to absorb shock as it moves down relative to the car.  He commented that what I described to him should be absolutely adequate.  In fact he's seen installs where the motor is tied directly to the chassis with no dampening material at all, so the motor feels every shock the chassis does to no ill effect.

We were all left scratching our heads.  I'm perfectly willing to accept the fact that it was something stupid that I did in the mount design or build, but I don't know what.  I'm also willing to believe that the putty just wasn't applied properly, but I have no evidence that's the case.  Presented with no clear cause to the problem, George stepped up and did what I think few manufacturers would do these days; he offered to fix it and cover the costs.  He and his crew arranged to have the motor picked up, shipped to Warfield Electric, fixed and shipped back at their expense.  I assure you this is not an inexpensive endeavor.

But then he went a full step further saying that if this doesn't fix the problem, he just wants to replace the motor.  I'm speechless really.  It's so reassuring to know that ultimately, I'm going to have a good motor.  On the other hand, I desperately don't want it to come to that.  At this point I'm certain that George has lost money on my motor, having to shipped and repaired it twice. He'd be better off never having heard of me.  This is a painful prospect to me.  The one way we have as consumers to vote for products we favor in the market and to support companies we believe in is to hand them our cash.  I don't know of too many causes, companies or products that I support more than EVs, Netgain, and the WarP motors.  So the fact that my "vote" has been nullified because of this pains me.  My hope is that this is the last time the motor is out of the car for repairs.  My hope is that the only time George hears from me again is when I tell him I'm buying another motor for another project.  Time will tell.

So, Netgain and Warfield have done their part to try and put a reliable motor in my hands.  The question now is what am I going to do?  As I mentioned before, I don't know if the way I had the motor secured to the car was the cause of my problems or not.  George may look at the car at the EV Converters Convention (EVCCON) in Missouri in September and say "Wait, you mounted it like this?!  You fool!!" and punch me in the face.  I don't believe there was a problem with the mount at this point, but I've decided there is an area where it could be improved.  Take a look at this crude drawing...

This is not too different from the old support with the exception that there is now some new rubber above the angle iron supporting the motor.  That additional rubber should offer additional cushion to the motor from movement.  In the previous mount, which does not have that upper rubber piece, if the chassis dropped down suddenly, the motor would be forced down, incurring a bit of a shock while it followed the chassis downward.  However, the new design will allow a little cushion to that shock providing some buffer to the motor when it moves both up and down.  What isn't represented there is the strap that goes around the motor to hold it down to the mount, and the bars mounted from the motor to the chassis for anti-torque support. 
Will this be sufficient to protect the motor?  I certainly hope so.  I've sent the design to George as well, looking for his input. 

At any rate, the motor arrived back from it's repairs yesterday and looks as beautiful as ever.  They even gave it a fresh coat of paint.  I'll be mounting it to the transmission over the next couple days and dropping it back in the car.  Once it's in place, I can start fabricating the new mount so it holds the motor in the right place.  I'm going to be building a whole new one from stronger materials rather than adapting the old one.  I think it will be easier to incorporate the change on a newer build. 

First Day Drive Report

The first day on the road was nice in many ways, but had a few drawbacks that I'll discuss in a moment.

The car is quieter than ever. The new vacuum pump seems to have two stages. The first stage, and loud one, seems to draw the vacuum down pretty quick, but then it switches to a different mode where it becomes much quieter and to finish the job. It's important to note that when I say "loud stage", that is relative. It is still 1/3 as loud as the old pump. The nice thing is that it never seems to go all the way back to the first stage in normal driving. It just kicks in with the second stage when I hit the brakes. It's so quiet, I can't hear it in the car. I can feel it in the floor, because it's mounted very near my feet, but I can't hear it at all. I couldn't be happier with the new pump.

The drive line is beautiful. There is no wobble, which I expected, but it's actually smoother than before. I'm not sure if this is due to the fact that the motor is better balanced than before, or because the flywheel is absolutely balanced now. My bet is on the flywheel. In either case, it's great!

On the very first drive, I pulled into a local shopping center, and a mother was waiting to cross the street with her little girl. They paused and waited for me to pass, and I parked near by. The mother then told me that her daughter thought my car was very pretty. I thanked her and told them that it was also electric. The mother stopped dead in her tracks and said "You're kidding." "Nope!" I replied. She simply said that it was cool and amazing. A nice little interaction.

Now for the rough bits. Driving in Phoenix, in the summer time, at 1:30 in the afternoon, with out AC sucks. There is no other way to put it and no way around it. It was 110°F in my back yard before I left, which meant it was easily 115°F on the black top. It takes almost no time at all for a person to get really sick of that.

Apparently, the Zilla does not like it either. Towards the end of the trip, I noticed the "Check Engine" light flashing slowly. While I can't say with certainty that it was caused by high temperatures, based on a number of factors at the time, it certainly seemed it. I didn't have a chance to get the error codes off the hairball before they'd been pushed away by different ones (I was doing a little experimenting). But I did put my hand on the controller to check and found that it was too hot to leave my hand on it. I measured it with an infra-red thermometer and found it was a 126°F. I verified the pump for the water cooler was working and the fans mounted to the small radiator were spinning. All is working, it's just too damned hot.

Sadly, adding AC to the system is only going to make things worse. I have no where to put the radiator for the Zilla except for behind the condenser for the AC system. So if that starts spewing out heated air from the AC system, the Zilla will over heat for sure.

The DC to DC converters continue to run their fans non-stop. The ambient air temperature, coupled with the heat they generate while operating must be above the temperature threshold. I'm not sure I can do anything about this. I'm going to prop a fan on a chair and point it straight into the back of the trunk. If they shut off, I know I simply need to find a better way of circulating air through there. If they don't, I'm not quite sure what I'll do. I let them run for 12 hours and found the fans and the DC to DC controllers sucked a full 500 W/hours from the main pack.

I'm still working on getting data on which will be the best way to go with the 12V system. Should I disconnect the DC to DC converters when the car is off, or the SLI battery? I have two pieces of data now. The one I mentioned in the last paragraph, though it's important to note that this was with the 12V SLI battery disconnected. If I shut down the DC to DC converters and let the battery handle the load, the car draws off only 44 W/hours. That tells me two things. One, at first glance relying on the SLI battery would seem to be the way to go; and second, these Iota DC to DC converters are energy hogs! I have more data to gather though before I make my final decision, and I'll share that later.

WarP Drive is Engaged

Let me start out by saying that I debated long and hard with myself whether I should use such a nerdy title for this post. In one regard, it's beautifully elegant and accurate in it's description of the current situation. On the other hand, it betrays the fact that I am a big dork. But, when it comes down to it, you must be true to yourself, so dork it is!

The motor is back in the car! I spent yesterday afternoon bolting the adaptor plate, hub, flywheel, and clutch up to the motor. Today I mounted the transmission to the motor assembly and then, with my dad's help, lowered it into the car again. I desperately hope that I never have to remove it again. But if I do, at least I'm getting good at it.

I got the linkages for the shift knob connected, and everything seem absolutely great at this time. Once it was all bolted down, I took some of the cardboard templates I'd made while waiting for the motor's return and started placing them in the engine compartment trying to sort out battery layout. It's looking more an more like getting all 31 batteries up front and mounted vertically is going to be easier than I'd first thought.

There's no question that I have a lot to do, but I'm going to attack it pretty aggressively over the next few days. I don't really know how long before I'm back on the road. I'd hazard a guess of more than two weeks and less than 3, but we'll see.

The Return of the Motor

The FedEx truck pulled up moments ago, and that could mean only one thing. The WarP 11 has made it's way back home. Wouldn't you know it, the same malcontent that picked it up when it left, lumbered out of the cab to deliver it. Sadly, his mood hasn't changed. Fortunately his sour attitude can not dampen my spirits; the motor is back and I can start the assembly process!

I mentioned before that I'm going to redo the battery layout. I may need to redo a couple other things to get the fit right. Stay tuned for all the fun :)

A Very Good Call

I received a call from FedEx late yesterday. They wanted to schedule a delivery from Warfield Electric for this coming Tuesday. The motor is on it's way home!

I'm astounded that the motor got back to Illinois, was repaired and will be back in my garage in 18 days. I'm not sure how NetGain and Warfield Electric pulled that off, but I'm ever so grateful to them that the have.

I should be able to get the motor back in the car by Wednesday, and then I can begin in earnest, the work of rebuilding the brackets and supports for the batteries.

The WarP 11 Has Left the Building

Friday afternoon, the surliest Fed-Ex employee ever stopped by to pick up the motor. It only took 10 minutes to get the paper work sorted out and get the motor loaded on the truck.

It took me the better part of a day to pack it. I no longer had the original box and packing material that it was shipped in, so I had to fabricate one. I put in multiple layers of cardboard and foam on the bottom and sides, and made some sturdy cardboard wedges to hold it in place in the middle of the box. It's packed in very tight and shouldn't move around during shipping.

I'd wager that it's going to make it back to Illinois safe and sound. Unless, of course, it takes damage from just being in the presence of such an overwhelmingly bitter and hateful Fed-Ex delivery man.

News on the Motor

I got an answer from George at Netgain, as to what that stuff was that was laying in the bottom of the motor. Apparently all that debris is balancing putty. Well, that explains everything nicely! It totally makes sense now. Why the motor and clutch were balanced at first. Why it seemed to fall out of balance all at once.

Without a moments hesitation, Netgain has told me to prepare the motor for shipment, they're sending someone to pick it up to take it back for repairs. Now that's customer service!

It's sad to see it go, but I'm thrilled at the prospect of getting it back balanced, strong and ready to go back in the car.

Now onto some other improvements on the car while I await the return of the motor.

More Bad News

Fresh off of yesterdays relief that the balanced flywheel was back on comes this disappointment. I had mentioned that there was still a bit of vibration from the motor and that I wasn't going to worry about it. Well, that turned out to be more wishful thinking than anything, and profoundly wrong. It is definitely something to be concerned about.

While working on the motor I had dented the steel shroud I'd made for the forced air ventilation for the motor. I decided to take it off and fix it. When I did, look what fell out:

I'm not entirely sure what that is (the dime is for scale, it wasn't in the motor). It's not metallic, or at least it's not magnetic. It looks like some sort of hard baked plastic. In either case, I'm pretty sure it's not supposed to be rattling around in the motor, in pieces.

For the most part, the motor is sealed. I have the shroud on one end that allows me to force air into the motor to cool it, and there is a 1/8" mesh screen on the other where the air comes out. There's no way for anything to get in there to cause damage. So it would seem that what ever that is, failed on it's own, and failed catastrophically. I guess that explains why I didn't start noticing any vibration for several weeks while I'd been using the car. The flywheel didn't just fall out of balance, the motor did.

I have an email in to the fine folks at Netgain. I'm sure they'll be able to tell me what's going on and help me get it fixed. One thing is certain, and that is the EV Z3 is not going to be back on the road for a while. I plan to use the down time to do some other improvements to the car, so stay tuned.

Good News Everyone!

Well I bolted the flywheel up to the motor and spun it up. What a difference! The wobble was almost entirely gone. There is still a small vibration at around 500 rpm while the motor spins up, but when the RPM's climb just a little higher and beyond, it is as smooth as glass.

Now I just need to get the pressure plate mounted back up and start re-assembling the drive train. Mounting the pressure plate is going to be tricky as it is naturally sprung to push on the clutch disk, meaning I have to collapse it about 1/2" to get it on. When it's new it has a retaining system that holds it until you bolt it up, making it easy to get it on the flywheel. Well, that's gone so this could be tough.

Motor Pull

Funny, you usually see an entry in and EV blog called "Motor Pull" as one of the first entries. Certainly not one after the proud builder has put only 901 miles on the completed car!

OK, enough grousing. Here's the, once again, empty engine bay.

My dad was kind enough to come over and help me get the motor out of the engine bay. It was quick work. I had everything disconnected by 10:30 and we had the motor out 1/2 hour later.

The first order of business was to start testing. We pulled the transmission off of the adaptor plate to expose the clutch and flywheel. I secured the motor and we spun it up. Sure enough, there was the wobble. It took a while for the 12 volt battery to spin it fast enough to see the wobble, but it got us there.

Next, we took off the pressure plate. So only the fly wheel was mounted to the hub. We spun it up again and... wobble. OK, so now we can check off the pressure plate and clutch disk as the cause. Next we removed the flywheel, leaving only the motor and the hub.


We put the battery on it again and watched carefully. There was still a bit of wobble, but it was substantially less. Perhaps 85 to 90% of the wobble was gone with the flywheel off. So, here's the culprit:


I was kind of surprised to see that there was some wobble with the flywheel off. I did what George from Netgain suggested. I spun it up and looked straight down in the hub. There was no sign of movement at all. I held a piece of aluminum right next to the side of the hub as it spun to see if it rubbed periodically or consistently. There is no variation in the spin at all. Perhaps the slight wobble that we see is from a slight imbalance in the motor. All I know is that it is very minor and there is absolutely no play in the shaft or bearings, so I'm not going to worry about it.

Next I need to get that flywheel down to a shop that can balance it.

Disassembly

I put the car up on jack stands yesterday and began disassembling it this morning. So far so good, but it's been very slow going. I'm not sure if I should be proud of how well built and how secure everything is, or ashamed it takes so much work to take it all apart. I used to curse engineers that made working on cars this difficult. But then I'm not an engineer, so I guess some slack is in order.

The batteries are out of the first two trays. Later I'll tackle the back box.


I received some encouraging words from George Hamstra at NetGain Motors. I wrote to tell him of the vibrations and that I'm taking the car apart to fix it. I'm worried that the motor may be damaged, which is causing the vibration, or that the out of balance clutch assembly might have damaged the motor. He said that it was highly unlikely that the motor was damaged, especially if I caught it in time. I'd put less than 100 miles on the car since I first noticed it, so I think I should be good. As soon as it's out, I'll test it and report back.

I'm thinking the reason it's gotten worse is likely due to the failure of the pilot bearing that's seated in the hub assembly couples with the transmission shaft. It was new when I put it in and probably helped to mask or limit the vibration. But I'll know more when it's out and I can see.

One thing I haven't mentioned is that I'm going to take this opportunity to improve the car a bit. I'm going to redo the lay out of the batteries in the front end. When I decided to go with lithium cells, I'd already designed and built all the supports for the lead acid. I had figured there was no need to redo the existing supports, so I worked to get the lithium cells to fit into what was already there.

Later I realized the mistake I'd made, it posed two problems. First, there is some debate as to the proper way to orient the batteries. People weigh it on both sides. Some say that you can orient them anyway you'd like and it won't harm them, while others say you MUST keep them upright. The truth is that no one knows for sure. But there is one certainty, and that is the manufacturer says they should be mounted upright. I haven't seen any elaboration on why, but if they say it, that's good enough for me.

The second reason is ease of accessibility. Every month (twice) I'd do some basic maintenance on the car, checking for loose nuts and bolts, and making sure there were no other problems. I'd also tighten all the bolts securing the copper straps that connect all the batteries. You'd be surprised how much they can loosen up in that time. Well, I'd check all but about 7. There were 7 I simply couldn't get a wrench on. I realized early on that this was bad and that I'd have to do something about it. So now I get the chance to do just that.

I think I've figured out a lay out that will accommodate all the batteries in the engine bay, let me get to all the things I need to get to and still let me shut the hood. There will be much more on this as I progress.

Bad News Everyone

I'm afraid I have no good tidings today. Let me get straight to the meat of the story.

Last Sunday, I left the house in the Z3 with the usual EV grin on my face. A few houses down I noticed a slight vibration through my hand resting on the gear shift. I thought "Hang on, I don't remember this." But it was slight and I hoped it was my imagination. Well over the next few days I realized that not only was it NOT my imagination, but it was getting steadily worse.

Of course, I immediately went into trouble shooting mode. Ultimately I was stopped on the side of the road, with the car in neutral, carefully revving the motor. Sure enough, the vibration started up at about 2000 RPM. It was worse at about 2500 RPM, and then seemed to start abating, but it did not go away entirely. Since I was sitting still, that rules out the possibility that the imbalance lies in the transmission or beyond in the drive line or wheels. It is in the motor and clutch assembly.

I pushed the clutch in, held it and revved again, same thing. That test ruled out the clutch disk since it wasn't spinning with the motor at that point. The vibration was still present. That leads to the following conclusion. One of the following things has managed to fall out of balance: the motor, the flywheel or the clutch plate.

I find it hard to believe that a solid hunk of aluminum has somehow gone out of balance, so I think it's safe to rule out the flywheel. That leaves the motor or the clutch plate. Unfortunately, each of those seems as unlikely as the next, but there's no getting around the fact that one of them has gone out of balance.

So, what next? Well, I can't leave it this way. I noticed it getting worse in only 4 days and about 100 miles. There's no way it's going away. It will only get worse, do more damage and get more costly to fix. I'm going to have to pull the motor and transmission assembly, dis-assemble it and find out who the culprit is.

So there you have it. Hopefully I won't be out of commission too long. I had to drive my old ICE Passat this past weekend. I definitely miss the EV grin. Please feel free to leave your condolences.