# EV Newbie, bought DC forklift motor off Ebay



## major (Apr 4, 2008)

doctormap said:


> I have read that this can result in "arcing" although I'm not sure what that means.


Hi doc,

It means big sparks from the motor where the brushes meet the commutator surface.

Post up some photos of the motor and we might be able to suggest how to advance.

If you keep a reasonable current limit and don't get too high in RPM, you might survive on neutral, but a mild (5 to 7 degrees) advance would be beneficial.

major


----------



## doctormap (Mar 28, 2008)

Here are a few photos of my motor. It doesn't have an I.D. plate. It has four terminals and four brushes. It has a gear on the splined shaft that I plan to use to make the coupler. The brushes are right up against the attachment, so it would be hard to move them any farther in that direction.


----------



## Duncan (Dec 8, 2008)

Hi Doc

You can advance that motor by taking the com end housing (the aluminium bit) off and drilling and tapping new holes in the yoke (the big black steel bit in the middle) so that the com end bolts back on 5 - 12 degrees advanced

The two bits will almost certainly be spigoted together so the bolts won't be locating them 

10 degrees at 7 inches diameter is about 0.6 inches - so drill and tap 0.6 inches away from the current holes - the bolts are probably about 3/8th so 0.6 inches should be enough clearance


----------



## major (Apr 4, 2008)

doctormap said:


> Here are a few photos of my motor. It doesn't have an I.D. plate. It has four terminals and four brushes. It has a gear on the splined shaft that I plan to use to make the coupler. The brushes are right up against the attachment, so it would be hard to move them any farther in that direction.


Hi doc,

First off, those comm segments look pretty narrow (meaning a fairly high bar count, maybe 57), so the motor maybe commutate acceptably well in your application (meaning arcing won't be too bad). Unless you anticipate high currents and/or high motor RPM, I'd be tempted to use the motor as is. Once you get your EV up and running, somehow monitor the arcing. If it is too frequent or excessive, pull the motor and advance it then.

To advance the brushes I would twist the entire CEH, comm end head, which is the aluminum casting containing the brush holder ring. This can be done either by redrilling and tapping the 4 holes in the steel frame or by redrilling the thru holes in the CEH where those long bolts go which attach it to the frame. It looks like there may be just enough space in the relief pockets to do that. When this is done, you may find that you have interference with the brush and connector coming up from the frame. So it may need to be repositioned.

Or you can send it to Jim Husted and have a pro do it for ya 

Regards,

major


----------



## doctormap (Mar 28, 2008)

First, let me thank you very much for your kind replies. 

I understand exactly what you are suggesting, and I agree that this is the right approach. I have a difficulty that I see. The copper bar that sticks out (from the field coil) that the brush is screwed onto will be in the way when I try to twist the CEH, so I would have to pull the end off completely and then put it back on in its new position, then re-attach the wires the other way round, as the attachment point will be on the other side. I have tried (vigorously) to remove the CEH, but without success. I don't know why it won't come off. It moves about 1/8" or so, but then it sticks and I cannot get it off any more than that.

So, I think that for the time being, I may elect to leave it be, go ahead and set up my system for 96 volts and see what happens. I don't have a lot of money tied up in the motor ($150) so if it makes a mess, I will get a new one.

I will be using the car just for commuting back and forth to/from work, across town, six miles each way, no hills, the maximum speed limit is only 40MPH, so maybe it won't be under enough stress to cause any problems. (?)

What do you think?


----------



## major (Apr 4, 2008)

doctormap said:


> What do you think?


Go for it


----------

