Ben Nelson's Electro-Metro Build thread

[bennelson]

Not sure where the XR3 thread will be posted. Either Fossil-Fuel-Free, as it will be all electric, or Motorcycles, as it has three wheels.

I hang out in Fossil-Fuel-Free, but we could really use some more cool projects in the Motorcycle hanger as well.

[sonic]

I just wanna tell you all that it's been a great read for me this thread. A few pages a day from the very first to the sweet end. Almost like something comming out of Dan Browns pen (a new career prehaps, The EV Code).

Btw, when I read trough this I noted that you didn't put a support for the heavy electric motor to the frame. Is this something I missed, is it just hanging on to the transmission bowl? If so, is it intended to be like that? I wonder cos other builds I've seen have put on a rack either from the middle or the back of the motor.

Anyway congrats to your new car.

Greets from Sweden

[bennelson]

Thanks Sonic,

Good question on the drive motor mount. It is a big, heavy motor, and YES is does need and does have a support.

The original car setup, with the gasoline engine has three support points for the combined transmission and engine.

The transmission is supported on the driver's side, and at the back, near the firewall. The engine has one support on the passenger side , and the rest of the engine is held up by being connected to the transmission.

My electric motor BARELY fit in the car. I needed a way to hold up the back end, but it had to be simple and slim. Also, I didn't have a welder, so I was limited in what custom parts I could build.

The back end of the motor has four nice large threaded holes in it, just waiting for a bolt to go right in.

I ended up using a turnbuckle from the hardware store. I ran a bolt through the eye of the turnbuckle into the end of the motor.



I slightly bent the other end of the turn buckle, and slid the bolt that held the original motor mount through it. That bolt is covered with a piece of scrap rubber hose to act as a mini-shock absorber and keep anything from sliding around.



This has seemed to work well as a motor end support so far. It didn't involve any welding, and was a part I could simply pick up from the store. It's also adjustable, so I was able to install it and THEN fine tune it.

Since I now have some new EV-building friends (with welders!) maybe I can design something a little nicer, which will go into two bolt holes in the motor.

I think this new motor mount is what I was test-driving when I got the speeding ticket! Before the turn-buckle, I had a piece of metal bolted in there from the motor to the frame, basically doing the same thing, but it was pretty flimsy. The motor was held up, but not well, and the motor really could twist in place too much.

[Christ]

Ben - that looks like one of my "last minute mods" to keep things working as intended LOL.

Just a thought here - fail if it you don't like it:
A crescent shape, covering two holes across the diameter of the housing, and a third hole at the apex, with a radial protrusion, and a stock engine-side motor mount bolted to it, that fits in the original frame-side mount.

The whole part could be cut from one solid piece of 3/8" aluminum.

I'll attach of sort-of blueprint diagram (ms paint) thingy in a few.

[Christ]

Blue (black and red, actually) print for your motor mount, c/o MS Paint.

[bennelson]

ChrisT, that looks pretty nice.

That's more or less what I was thinking in terms of a nicer "final" motor mount.

Maybe I could make one in the shape of the Ecomodder "Wrench" logo!

[bennelson]

My ride today was not a great one.

It was the typical library, grocery store, bank type of a trip I built the car for.

But it was cold outside! The official listing of temperature said it was 18℉ (-8℃) but it felt a little colder than that.

I did not preheat the car with the electric oil radiator. It was a very cold ride.

Coming back home, the volt meter was dipping more quickly than I would like for how many amps I was pulling.

Of course when I get close to home, that's where the speed limit changes from 25 to 45. At that point I could only get the car to 25 mph max.

I used google maps to calculate my exact route (I don't have a trip odometer) and it came to 9.2 miles.

Less than 10 mile range in the cold! Ack! I will have to wait until the car is recharged to figure out my exact power usage. It will be interesting to see what the "true" amp hour capacity of my batteries is in the cold at electric car amp rates.

[Christ]

NP for the mount diagram.. took like 30 seconds in paint LOL.

[sonic]

That turnbuckle mount looks to stiff and to weak at the same time. On the original rubber mounts (that holds the transmission) there are some flex, 1-2cm perhaps. With that set-up you have 2-3mm tops. So when the transmission flex the motor can't. Something will snap, most likely the bolts on the turnbuckle. If I were you I wouldn't drive the car until a proper mount is installed (like the drawings) with same flex as the tranny, if you have the old original you're halfway there. As a bonus you get torque twist support also.

The EV I'm planing to build (still in my dreams) I will use a Webasto / Eberspächer diesel heater, connect to the water heat pack with a small tank. That way I can have full heat without draining the drive battery's. Also I can pre start the heat some 30min before take off, the car warm and ice free. Another idea I have is to rout some air tubes from the heater to the isolated battery packs, so they are also warmed up to get max amp out em.

[bennelson]

The turnbuckle mount is actually working surprisingly well. It's beefy and solid feeling. I am not sure about the whole "flex" thing.

Yes the original engine mount would have had more flex to it.

I was still planning on eventually replacing it with something else. Maybe I'll just work on it sooner rather than later.


I like the concept of a diesel heater (running biodiesel). It wouldn't drain the batteries, and would have a high heat output. Using it to heat the batteries is also a good idea, although you would have to get clever in how you run the air tubes, and it would have to use a heat exchanger to keep combustion by-products outside the car and keep burning fuel away from potential hydrogen gas from batteries.