Ben Nelson's Electro-Metro Build thread

[TomEV]

You probably know, but 4 wires on a DC motor generally indicate that it is a series motor. The two at the end (away from the shaft) are probably the brush wires (A1, A2) and the ones more in the center are probably the field wires (S1, S2)

[bennelson]

Jim Husted got back to me about the photos of the big pump motor.

He said that particular make of motor tends to have brush arcing issues. And, as I can tell, the drive shaft isn't particulary good for driving an EV.

He said that I could try replacing the drive shaft, but it might be a big hairy pain in the butt.

I still need to get the other motor off and see what that has on it for a shaft. The other motor isn't quite as big, but would be reversable.

Then I will try to compare the two and see which will make for the better motor.

[MetroMPG]

The drive motor will have a much better shaft end as well, and probably has a coupler you can modify to your needs.

[bennelson]

I was finally able to get the drive motor off the forklift!

What a lot of work that was!

Also, while I was really making sure to keep my fingers away from giant capacitors and crushing-weight motors, I managed to smash my skull into the pointy corner of the motor compartment swing door.

Good thing I was wearing a knit cap, or I would have either lost consciousness or be at the hospital right now getting stitches. Ouch! (Where's the smiley with the band-aid?)

The drive motor does have a shaft on it, but it isn't nearly as big as the large pump motor - that weighed about 120-140 lbs, the drive motor only weighs just under 90 lbs.

I also removed the controller electrics. Most of it is all together on a plate of aluminum which was held to the forklift frame by one bolt. The trick was to get at all the places the heavy battery and motor cables went too. Once I was able to figure all those out, it came right off.

I also got an e-mail from my wife today:

"Hey Ben,
If you get a chance - could you please look for the bathroom scale?
Thanks
Kristin"

No, I am not making that up...

More photos available at: my photo page 2

[MetroMPG]

Originally Posted by bennelson

If you get a chance - could you please look for the bathroom scale?

You know how to interpret & translate that, right?

[bennelson]

Originally Posted by MetroMPG

You know how to interpret & translate that, right?

I think it means "degrease the scale and get it back in the bathroom!"


I stripped the rest of the items on the forklift that looked like they might have any use for the electric car.

Items include:

Motor controller contactor board
Electronic switch key
Yellow blinking light (doesn't blink, might need new bulb)
Heavy welding cable
Horn (nice low tone)
Joystick control with switch on top and horn button on side
Set of male and female heavy duty power connectors (matches charger)



Everything else seems to be either plate metal body, or hydraulic related.

Other than the forks. I guess those are fairly standard and easy to move from one lift to another, so I should be able to sell those all by themselves.

[bennelson]

I cleaned up the drive motor a bit.

Looks much nicer without all the grease on it.

Also, it looks to have a pretty normal driveshaft on it. The shaft is 7/8th" diameter with a standard channel groove. I was also able to remove the gear that was on there. Makes a neat paper-weight.

Not sure if this motor is big enough for the car motor or not though. Seems a little on the small side. It is almost 10" outside diameter, but not too long. It also looks like it has 4 brushes, whereas the big pump motor has 6.

However, this one should also be reversable, allowing me to get a Honda OR non-Honda and make the motor spin the correct direction.

As always, there are more new photos on my .Mac page, now on page 2

[MetroMPG]

Glad to see the normal shaft with the keyway!

When you talk to Jim about this motor, make sure to remind him what kind of performance & specs you're expecting. Whether or not he declares it a useful motor or not will depend on whether he thinks you're doing a 48-72v grocery getter, or a 120v highway machine. (He's used to talking to the high-power, high-speed boys, and it colours his thinking. Not disparaging him at all - he's an incredible guy for all he helps people!)

PS - when you say 4 brushes, do you mean 4 brush pairs?

PPS - FYI the male/female connector is commonly called an Anderson connector.

[bennelson]

ANDERSON connector, that's the name I was looking for...

The brushes on the drive motor look a little different then they did on the pump motor.

I haven't gotten the end off yet, so I can only peak thru the view port/air hole.
The brushes are straight, they were angled on the pump motor.

It looks like the drive motor only has one brush in each position. Am I seeing it wrong?

[MetroMPG]

Looks like a single brush. How wide is it? Hopefully Guru Jim will chime in this evening.

For reference, inside our pump motor...

You're looking head-on at a brush pair (2 braided copper leads per brush, like yours). I'd guess the brushes are about 1 1/4 inches long.