Sunday, September 17, 2006

Adaptor Plate Design Considerations

Since the last post, I've decided to design the adaptor plate myself and have it machined locally by a friend. I've been busily working on a design for a while now. I've got the basic idea roughed out, and I'm currently working on turning it into something workable. Here's what I've done so far:

1) I traced the transmission bell housing outline and bolt holes onto a piece of high density cardboard. The next step is to cut this out using a scroll saw and bolt it up to the transmission to see if it will fit. Then, I'll find the approximate location of the shaft and cut an oversize hole for the hub. I will then have an adequate pattern for the profile plate.

The profile plate doesn't have to be perfect, thanks to the way I intend to mount the motor ring. I will drill the bolt holes to mount the motor ring a bit oversize. Then, when I install it, I can tweak its location until it lines up perfectly. I can then drill and pin it to lock it in place.

The motor ring also sets the spacing for the flywheel. This way, I can just cut the profile plate (which is larger than the motor ring, and more tedious to machine to thickness) out of a piece of 5/8" thick aluminum and not worry about thickness.

2) I did some design work on the hub. The most difficult part is actually determining the method of attachment to the shaft. I've considered several options. The two that I've spent the most thought on are the taperlock and the setscrew. At this point, it seems like the taperlock hub would be the best option. There doesn't seem to be a good way to keep a setscrew from loosening under these conditions.

The downside to the taperlock hub is that it's kind of hard to design. I don't know what the dimensions need to be for something like this. For instance, in order for the taperlock hub to work properly, the tapered bushing must be slightly larger than the recess that it fits into. I don't know how much larger it needs to be. I'm slowly getting it figured out. If anyone out there has any information regarding the taperlock hub, I encourage you to let me know through a comment here.

So, that's where I'm at for now. For those who aren't familiar with the taperlock design, I might detail it in another post. Right now, though, it's kind of late at night and I'm too tired to write it. Keep checking back for updates!

Saturday, September 09, 2006

The Adaptor Plate: A Necessary Evil

The adaptor plate is the piece that connects the motor to the transmission. It consists of three parts: the aluminum transmission profile plate, which is cut and drilled to bolt onto the transmission and replicate the original mounting surface of the engine; the steel hub, which attaches the motor output shaft to the flywheel; and the aluminum motor ring, which acts as a spacer between the motor and the transmission to keep the correct spacing for the clutch. Several small spacers between the motor and profile plate are sometimes used instead of the motor ring.

I now have to decide if I want to get the adaptor plate made at a local machine shop or if I want to get it made by a specialized company out in California. I was originally thinking that I would just get it made in CA. They have a library of patterns for various cars and motors, and at the time I thought they had a pattern for my truck on file. The catch: if they don't have a pattern for your vehicle, you have to ship your transmission out to CA and get it measured.

The problem arose when I realized that my truck didn't have the original engine and transmission in it. When I went to get a distributor cap and rotor for it (back in the day when it still had an engine), I just got one for an '88 B2200. I mean, duh, that's what kind of truck I have. When I came back with the cap, it didn't fit. That's when things started to get fun. It turns out that the original distributor cap was off of a 2.0 Mazda, not a 2.2. I then noticed a whole bunch of pinched off hoses and unplugged connectors. And then, as I was removing the transmission, I noticed that the crossmember had moved forward to accommodate a new transmission. I just assumed that it was out of a B2000, because of the distributor cap. The company out in CA had a pattern for this transmission, so I was golden. For a little while, anyway.

Fortunately, I got in touch with another EV guy who is in the process of converting a B2000, and he sent me a pic of the bell housing on his truck. Mine looks nothing like it. Oh well, back to the drawing board. I'm going to see if the auto parts store can run the numbers for the transmission so I can find out what it is.

Having actually seen the clutch assembly and how and what it bolts to, I'm now thinking that it wouldn't be prohibitively difficult to get the plate made locally. I'm going to see about coming up with a sketch and maybe a template to take down to the machine shop, along with the transmission, flywheel and clutch, and motor, to see what they charge for something like that. Wish me luck!

Next: Who knows? Could be anything from battery boxes to heater cores.

Thursday, September 07, 2006

I've been very busy lately, working on various projects (including this one). With school starting and everything I haven't been able to find the time to update this page. Hopefully now that I have things under control I'll be able to update this more often. I guess I'll just start where I left off:

ICE Component Removal

This is easily the most tedious part of the project, for me at any rate. It's also the dirtiest. It's a good reminder of how much cleaner EVs are when compared to ICE-powered cars. The ICE car requires antifreeze, oil, and gasoline to run. An EV requires none of these. Not to mention, EVs require much less maintenance than gas cars. They don't require oil changes or oil filters, they don't need alternators, timing belts, distributor caps or rotors, and a slew of other things. All they need is to have the motor brushes replaced every 80,000 or so miles, and the batteries topped off every once in a while. The batteries in an EV also need to be replaced every 3-5 years. Even including these things, EV maintenance is much cleaner and affordable than ICE maintenance.

I started by draining all of the fluids. Luckily for me, this was a simple task because I had run the truck out of gas before conversion. I didn't drain the oil because the engine is probably just going to go in some other project anyway, and draining the oil would have been a waste of time. The one thing I wish I had drained, but didn't, was the transmission fluid. I remembered this right before it all started draining out as I pulled the tranny out. So, I ended up with an empty transmission and half a bag of cat litter all over the garage floor.

I then removed the radiator and any other pieces that could hinder the removal of the engine. That included the fan and clutch, ignition system, wiring harnesses, fuel, vacuum, and antifreeze hoses, air cleaner, etc. I then loosened all of the bolts holding the engine in, and set off to rent an engine hoist.

Engine removal was pretty straightforward. The engine pretty much just slid right out, after a little tinkering to get the transmission shaft disengaged. I then decided that it would be best to pull the transmission as well. It'll be a lot easier to bolt the motor up to the transmission if it is removed from the vehicle. Plus, I'll get a chance to degrease it and perhaps paint it. The only problem is this: the transmission is a very annoying object to remove, with lots of little connections cropping up everywhere, and that obnoxious shift lever sticking up in the middle of the truck. I ended up dropping the crossmember and lowering the rear of the transmission instead of removing the stick.

Once everything was out of the truck, I had a very greasy engine compartment to work with. Since the electric motor is very clean, and will not spew oil all over the place like the ICE did, it made sense to clean up the engine compartment before proceeding. So, I rented a pressurewasher and got to work. A couple of hours later, I was rewarded with a sparkling clean engine compartment. Well, almost. You can see what it looks like now in the photo at the top left of this page. Pretty empty, eh?

Next: The Adaptor Plate and Related Issues