Ben's Elec-Trak

[bennelson]

The hole for the driveshaft is so close to the bottom of the mower, it's going to be difficult to fit a motor of any other size in there.

I am not sure where to find an OEM motor from, especially at a reasonable price.

I may stop out at the forklift motor rebuilding place that I got my brushes from. They were very friendly and have TONS of motor cores around. I might be able to find the right one there.

I plan on bringing the mower out to the next EV Build Day, this Sunday, in Milwaukee.

[Christ]

Could you just replace the outer housing?

[bennelson]

Nope, "Just replacing the outer housing" isn't going to work.

(EDIT: I later got a chance to visit a forklift motor rebuilding company. The leadman there told me that the "magnet ring", the middle outside part of the motor with the permanent magnets attached, is actually a very common size. However, it is almost always used with pump motors, which do NOT have a drive shaft on them. HAD the armature come out with no damage, I very well COULD have just "replaced the outer housing". END EDIT)

I got a chance to actually remove the motor and take it apart. My worst guess was confirmed. The magnet shattered and jammed everything up, including messing up the armature.

Ick! What a mess!







Yes, that is shattered magnet everywhere.
I think that because the motor sits in the bottom of the tractor, rain water was getting in there for years, rusting it out. I believe that corrosion caused one of the permanent magnets to separate from the housing enough that it started rubbing against the armature and causing all the trouble.

Notice in the one photo how you can see the rust color where the magnet was.

See more photos of destruction here:
http://gallery.me.com/benhdvideoguy#101650

[Christ]

Ouch - that motor is toast.

[bennelson]

The Elec-Trak now has a new motor!

Special thanks to good old Tom G. for his super-special-scrounging skills!

Photos to come.

[Daox]

Wooohoo. I was planning on being there and now I'm regretting it. I just had too much stuff to do on the home front.

Have you tested the new motor yet?

[bennelson]

Yep, tested the new motor.

Tom had two motors that were rated at 1/2 HP and 24 volts. The shell of the motor was the same diameter as my wrecked drivemotor, but it has a larger face plate, and different mounting holes.




I looked to see how I would need to drill new holes and mount the new motor.
Here's the best part. The holes were already there. There was a second set of mounting holes that exactly matched the new motor!

I mounted the new motor with some shiny stainless steel bolts.


(Notice the unusual bolt pattern. The lower left hole is used for EITHER of the bolt configurations. The upper right hole had a plug in it, and the lower-right hole is hidden behind the pulley. Because of all that, I didn't immediately recognize that there was a second motor mounting bolt pattern. I was pleasently surprised when I found out it matched perfectly with the new motor! Also, this motor sits UP from the bottom of the mower. I believe the original motor was wrecked because of rust from it sitting in pooled rain water in the bottom of the mower. The new motor no longer sits on the bottom of the mower, so it should be much less of an issue.)

Once it was on there, I spun the motor with the batteries, and held some Scotch-Brite against the shaft to clean off the surface rust.

The original motor had a 7/8" shaft, but the new one was smaller. We dug around Tom's basement, and found a 3" pulley with the right inside diameter for the motor.

We put air in the tires and and test drove the mower in the bottom of the driveway and the street. The blades are hooked up to turn on and off with a contactor, but the motor was powered by connecting/disconnecting a big Anderson connector.

We all figured it would be a bad idea to have both the blades and motor controlled at the same time with the same contactor, because then you could never drive the tractor around without the blades on.

Better is to add a seperate switch for the motor. We had a 100 amp disconnect key switch around, and figured that would work.

Since I am not using the tractors original charger - a big old transformer with a timer switch - we pulled the rusted old timer out, and drilled the hole bigger to add the power disconnect.



When I got home, I mowed one section of my lawn. The drive motor seemed to work well. It doesn't go up the big hill out by the road super-great, but my gas tractor never really did either.

The speed of the tractor is pretty good. I wouldn't mind a little faster speed in the highest gear, but I don't think I want to give up torque for now either. I still plan to add a snowblower for the winter, and will want all the power I can get!

[Daox]

Oh boy, now I'm jealous! You're already mowing! I haven't touched my mower in weeks, although I did finally get a belt for it yesterday (which is what I've been waiting on).

[bennelson]

Here is the mower parked next to the solar panels.



And here you can see the charger controller for the panels sitting on the right-side footrest of the mower.



The power lead wires on the charge controller are a bit short. I will need to make some longer ones. Another possibility is to mount the solar panels on a roof-rack of the mower. I LOVE that idea, but leaving the mower out in the sun also means leaving it out in the rain.

I think that solar panels outside, charge controller and lawn mower inside, is going to be the best way to go.

Solar panels on the roof (or even the hood) sure would be a great way to show off though!

[bennelson]

Wow, last post from me about the mower was from last summer!

Well, I got to mow my lawn a couple of times last summer, but the mower still needed plenty of work.

Recently, I started pulling a few parts off for cleaning, repair, and painting.

For example, I removed the rear deck ( back cover/seat holding part) and took off the seat.



I got all the paint and rust off of it as best I could, with a combination of a citrus-based paint stripper, a flapper wheel on an angle grinder, and a rotary brush on a drill.



It actually looked pretty good after a coat of quick-dry automotive primer.


A coat of yellow Rustoleum spray paint, and it was back on the tractor. (I have ZERO spray-painting skillz! I went over it with another coat later.)


My friend, Tim, has a powder-coating system and an old electric over in his garage. I have heard that powder-coating is one of the best ways to paint metal parts. I asked Tim if he would give me a hand painting a few parts.

I stripped several smaller parts from the tractor, and sand-blasted them over at another friend's work.

Here's what the front bumper, belt guards, and seat support bracket looked like after sandblasting.

I have never done any sandblasting before, and was amazed at the look. I would have expected a shiny silver look, but instead, the metal looked like it was just primed!

Later, over at Tim's place, we did a little more finish sandblasting, sprayed the parts with yellow powder-coat, and baked them in his oven.



Some of the parts turned out better than others. The curved belt guard ended up really nice. The paint clung to the curves of it very nice. It's a smooth, plastic-like finish. It should be very durable.

The other neat thing about powder-coating is that clean-up is easy. Since it's just a powder, it can be blown, brushed-off, or swept-up with a broom. Imagine paint like this if it were spray-paint!!!


The other more troublesome work was the rear wheels and transmission.

I took the tractor the the local EV Club Build Day, and some of the other guys helped completely remove the transmission from the tractor.
The rear rims were amazingly rusted on. It took quite some work with penetrating oil, a torch, and a very large puller to get the first rim off. The second rim actually broke the puller! We had to mangle that rim a bit to get it off.


The rims the Elec-Trak uses are an old style that I can't find anymore. The rim has a tube about 3 to 4 inches long, with a hole that matches up with a cross-hole in the drive-shaft. A clevis pin goes through that. The trouble with it is that it's really hard to get at the clevis pin when it's on the back side of the wheel. Also, the surface area is so great between the rim and driveshaft, that if it's a little rusty it becomes completely impossible to remove the rim!!!

Since I can't find any new rims of that style, I might be able to make an adapter. I can get plain "four-on-four"rims and tires for free if I look around. At the tool store, I saw that they had hub adapters for go-carts. It's a thing that slides onto a one-inch-diameter drive-shaft with four bolt-holes spaced out from it. I could drill out those holes bigger, and they would fit standard rims. Those adapters are about $20 each.

The transmission should also get new oil in it. I don't know if the transmission needs to get split open and inspected or not. The bolt heads are fairly corroded, and I would be worried about wrecking them and just causing problems.

Anyways, just chipping away at fixing up this tractor nice. It's over 30 years old. If I can make it run another 30, I will be a happy man.