Sunday, August 21, 2011

New powertrain and new skills

HPEV AC-50 Motor, adapter
plate (red thing), & clutch
The Electric Drive Train
It was a pretty good weekend on the EV conversion front.  I got a bunch more of my parts this last week including my electric motor!  The motor was built by High Performance Electric Vehicle Systems (HPEV) just 15 minutes down the road from me, in Pomona.  I got to visit their shop and meet one of the owners, Brian Seymour. Besides looking at their production line and learning about the history of the company (they've been winding motors for nearly 50 year) I got to drive Brian EV Porsche 911--pretty cool.  They've also done a really nice Jetta conversion
Motor bolted to the original, but
rebuilt manual transmission

Back to my conversion, the motor I'm using is an HPEV AC-50 which is an AC motor which can draw up to 650 amps at 115 volts. The motor bolts on to the original manual transmission using an adapter that mimics the end of the old gasoline engine.  My adapter was manufactured by Canadian Electric Vehicles. The adapter includes a plate that bolts on to the motor and the transmission and a hub that attaches to the motor shaft and bolts on to the original fly wheel.  Since I had the transmission out I replaced the clutch and throwout bearing at the same time. 

Motor and transmission going in
After bolting up the motor and transmission I enlisted the help of my friend, Chris, to put it all back in the truck.  We made a second trip to our local tool rental guy to get an engine hoist and drop that baby right in.  It was all going without a hitch until I found that I should have ground out a section of the adapter plate to make room for the clutch piston. Since we already had the rear of the transmission bolted in place I ground out the notch with the motor and transmission in place. It was a pretty ugly job, but it worked--a lesson in thinking ahead.  Anyway, we got the new motor and transmission in place.  Chris also replaced all four shocks for me.  I still need to fabricate a bracket to bolt the electric motor to the existing motor mounts on the chassis.
The notch I should have ground out
before dropping the motor in place

New skills
Speaking of fabricating metal stuff, I solved my problem of getting welding done by learning to do it myself today.  I had originally planned to purchase my welding services from a buddy by trading homebrew lessons and beer for welding but my welder is about to head off to Burning Man next week just when I needed his help.  Not to worry, he introduced me to another friend of his who taught me how to use his wire feed MIG welder and loaned me the equipment!

I learned gas welding years ago and tried, unsuccessfully, several time to learn arc welding.  Arc welding is a skill that required more time and patience than I had to learn properly.  Thankfully, in the intervening years two breakthroughs have made welding way easier:  wire feed machines, and auto darkening lenses.  With these new (to me) tools and my previous gas welding experience, I was off and welding in 30 minutes!  I worked on a couple parts of the the battery boxes.  My welds are still a little ugly, but they'll get better. I can't wait to spend some time this week welding up my battery boxes and a bracket for the motor.  I think I'll have to play hooky for a day--wait, it's still summer vacation, and I'm not getting paid--I don't have to play hooky, I just need to stay home and enjoy working on my EV project!

My supplier
A big shout out to Wistar Rhodes at KTA Services.  I've purchased all of my EV parts from KTA with the exception of the batteries.  I wanted the help of a knowledgeable EV vendor to help me select the right parts since I could easy ruin a $4,000 motor or $8,000 of batteries with the wrong parts.  I contacted several vendors and found Wistar at KTA to be both knowledgeable and helpful.  He's already spent several hours on the phone with me discussing the pros and cons of various components.  I found KTA prices to be very competitive. I recommend KTA to those that want help selecting components.

Thursday, August 11, 2011

Parts arrive!

The new fuel tank for the truck.
32, 3.2 volt lithium batteries.
The parts have started to arrive.  It's like Christmas in August!  I picked up the batteries from the local distributor today--all 450 lbs of them. The battery pack consists of 36, 3.2 volt, lithium batteries connected in series for a total nominal voltage of 115 v.  The batteries are rated at 180 amp-hours. If my calculations are right, this should give about a 50 mile range on a fully charged battery pack.  Now I have the task of designing the fixtures and boxes to hold the batteries. As I mentioned in an earlier post, most of the batteries will be going under the bed of the pickup between the frame members.  I've made a SktechUp model of the frame and the drive train, which you can see below.  It's a little crude but accurate enough to determine the basic battery layout. The layout below shows all 36 batteries under the bed.  I think I'll move some of the batteries up to the engine compartment to help with weight balance. The electric motor I'm putting in weights quite a bit less than than the gas engine I removed, so it will help to put some of the batteries up front.

First option for battery placement under the truck bed
I've also received a lot of the miscellaneous parts including, vacuum pump (for the power brakes), DC/DC converter (to run the 12 volt accessories off the 115 volt main battery pack), wiring, relays, fuses, contactor, throttle control box, & tools.  I'm still awaiting three major parts:  the motor, the motor/transmission adapter, and the battery management system.

Well I'm off to design some battery boxes.