Sunday, May 2, 2010

I stopped by the municipal garbage transfer station last week and weighed the car. The GVWR on the door nameplate is 3740lbs. I'm just sneaking by. Here's the original weights:
Front: 1580
Rear: 1408
Total: 2988
and the converted weights:
Front: 1780
Rear: 1880
Total: 3660
In both cases, that includes 230 lbs of me. The only variable was that I went different places for the weigh-ins. The first was a landscape rock yard and the second was a trash transfer station with a longer scale table. Whatever. I'm still going to drive it.

Here's the measurements on the ride height:





Wheel: Orig: Converted:
FrRt 25 7/8 24 7/8
RrRt 24 5/8 23 1/4
FrLt 25 3/4 25
RrLt 25 23 1/4

I do anticipate some stiffer springs in the rear. It's too soft going over railroad tracks.

By the way, that trip down to the scales was also my longest run to date, 16 miles at an average of 35-40mph. That route also included a 1/2 mile 10% grade (up) at mile 12. The car did great, started the hill at 45mph, then watched the ammeter all the way up, trying to keep it between 300 & 400A, and got to the top at 35 mph.

I definitely have a lot to learn about how to drive this thing. I still haven't taken the time to run it all the way down in an endurance test. I need to so that I'll have a little more peace of mind about running it on errands.

I have the Toyota connectors and pigtails to make better connections for the PS pump. The car is headed back to the shop for a couple of things:

  • Change out the control mounting board for a plastic butcher-block panel instead of plywood
  • Paint the front battery box
  • Rewire the PS pump connections
  • Move the PakTrakr CT from the control board back to the rear battery string (liberate space on the control board and easier running of CT wiring back to PakTrakr)
  • Splash shield for Commutator end of motor It's a journey, not a destination right?

Oh yeah, I also finally got around to pricing a new windshield. I was pleasantly surprised, it was only around $200. That will be money well spent. There's some nifty rorschach style cracks running back and forth across the original windshield. All I see is food. really. I think the only thing holding it together is the Lousisana registration sticker and La.State Patrol Supporter sticker (somebody in this vehicle's past was hedging their bets).

So much fun, let's do it again

As mentioned earlier, the next conversion project is my dad's Ford Ranger. The guys at Vision Steel hopped right on it, and already have all the big parts out and have cleaned up the chassis. This should be considerably easier than the BMW. Lots of access to the frame, more depth under the hood, etc. The other benefit is that all of the core electric components are the same and VS already has 2D files for the mounting brackets for motor, pump, etc. Here's some pix. I'll post the design goals in a separate post.





Tuesday, March 23, 2010

First Feeding



I stopped by the workshop today to plug in the charger and see what happens. Again, no sparks. The blinky lights on the charger made sense, so I left it going for the day. If he gets time, James is going to bleed the hydraulic clutch today, and I plan to bring it back home.

Remaining ToDos:

  • Install Battery monitor leads
  • Install Battery overcharging shunts
  • Finish Heater element and core
  • Reassemble interior
  • Drive back to the landscaping rock yard and run it across the scales
  • Locate pre-tear-down height measurements and take it to a local spring shop to see what options I have for stiffening the rear suspension
  • Assemble Lexan water shield for control board (so that in the future I won't have to wait for sunny days like today to drive)
  • Have the Vision Steel guys form some sort of under-motor-splash-guard (see above)
  • Replace Windshield


A little further out:



  • Take care of the paint job (rust on leading edges of hood)
  • Polish or replace headlight units (Angel Eyes anyone?)
  • Set up onboard data logger (CarPC or Arduino with WiFi interface, TBD) and touchscreen display
  • Rework control board; pull everything off the plywood and replace with HDPE (like a big white butcher block)
  • Install Tach sensor and wire to BMW Instrument Cluster Tach
  • Figure out Air Conditioning (we mounted the original compressor near the stub-shaft so that we could drive it off a pulley later on if I wanted to). I may go with a bucket of ice instead.

Way Way Out:

  • Scheme up some sort of removable forced-air motor cooling system for parade duty
  • Scheme up some sort of custom 144VDC-120VAC inverter so that I can use the car as a backup power supply in case an ice storm or tailgate party breaks out

Thursday, March 18, 2010

It's ALIVE



Not much time this evening to document everything, but I did want to at least post that we had the first test drive(s) this afternoon. I've definitely got the "EV Grin" that I've read so much about on the web forums.


It was a beautiful day, and I just couldn't think of any reason not to go ahead with the drive. Last night I hooked up the all the batteries and re-did the original BMW battery connectors to fit my smaller 12V house battery. I applied the heat sink goo to the controller and tightened all the electrical connections. There wasn't much else to use as an excuse for putting off the first tests. So, this afternoon after work, I went down to the workshop and we rolled it out.



There's a few issues to be cleared up. The power steering pump never came on. I'd guess that one or more of the flimsy pins in my fancy radio-shack connector pushed out instead of making contact. I'll check that out over the next couple of days. Additionally, we've got to do a better job of bleeding the hydraulic clutch; today it didn't really ever seem to release.



The driving was great though. Great pick-up, very smooth, no mechanical noises indicating misalignment of the motor shaft with the transmission. The brakes worked fine. I could hear the vacuum pump coming on and shutting off periodically as expected.


We drew quite a crowd at the shop this afternoon. The registration on the car has expired and the insurance suspended (on purpose....) so we couldn't head out on the roads. However, the parking lot between warehouses allowed for plenty of zipping back and forth. Several of the guys who've been watching were very surprised by the pickup. Several of them took turns getting behind the wheel, and everyone came out grinning. It's definitely an odd feeling.



On my first drive I noticed that the ride was very rough, almost wobbly. On my second pass, someone posed the question "Did anyone tigthen the lug nuts since we had the wheels off?" Sure enough, two wheels were very loose. See, some problems do have simple solutions.

Here's a link to the vide of the very first drive:
http://www.youtube.com/watch?v=dQ35INlX_Os
and another:
http://www.youtube.com/watch?v=Nfum0k7xur8


Wednesday, February 17, 2010

Signs of Life

By the way, Here's a video of my first test of the control wiring.

Here's what's going on:

  • Turn the Key (~11sec): This powers on the control board, drive cooling fan, and vacuum pump for brake vacuum. The click you hear is the first contactor closing. In fact, if you look hard at the contactor (small black box just above the hanging power connector on the right) you can see the contacts closing.
  • Turn the Heater On (19-22sec): I have a ceramic heater element inserted where the heater core was. I can turn on the heat only if the fan is on 4, and a separate heater switch is on. In the video, you hear the blower come on, and the click on and off of the smaller heater contactor. This is switching the 144VDC to the heater element.
  • Give it the Gas (~32sec): The accelerator cable is not connected yet, so I get out of the car and come around to the PotBox that will trigger acceleration. You hear and see the second contactor close (black box at the front of the board to the left) and in theory, now the power is flowing to and through the drive and you're on your way.

Saturday, January 2, 2010

One more thought this evening. This whole thing has taken longer than I'd hoped it would. I guess that's okay; at least I am moving forward. But now I REALLY need to get this thing done:
  • We closed on a new house last week and will spend the spring working on an addition and rehab projects.
  • My Dad bought a mid 90's Ranger for me to convert when I'm finished with the EMW.
  • Too many people have a vague fuzzy recollection that I was doing this project and are asking me "whatever happened to that car project?" And when I say that I'm still working on it, they assume that's code for "I gave up".

The good news on the new place is that it's got a nice 40x40 workshop where I can work on the Ranger and a three car garage so the EMW can stay inside where it's warm.



Closer, but still not there













I've made a lot of progress over the last week or so. I got two or three good days of work in during the holidays. Last week I was able to take care of both power cables and control wiring on the control board.






























I also placed all the batteries and finished the battery cables.




I fired up the vacuum pump today to see whether or not the switch was wired correctly. Apparently I've got some leaks; it wouldn't pull more than 5-Inches, and when shut off, didn't even hold that much. So I'll have to chase that down. I'm pretty sure I heard some hissing coming from my vacuum tank. Not surprising given that it's three pieces of PVC all glued together plus the fitting.




Here's the requisite shot of the charger cord in the fuel door. Nice work by the Vision Steel guys

on the tread-plate backer. You can see the Elcon charger on the rack in the rear-battery box pic above.












...and here's the first picture of the fully loaded car. Well, all the batteries and major components. The seats are still out, and I'm not sitting in there with my 200+ libbies. According to my original calculations, it should still come in under the GVWR. Just pushing on the four corners, it's not down on the stops yet, but it's pretty soft. I had originally budgeted for sport springs for this and it looks like I'll need them. The good news is that I shouldn't have to look too far to find someone with stiffer springs for a BMW right?