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Vintage Trinity Commutator Lathe (for stock motors)

Posted: Thu May 16, 2024 2:25 pm
by JosephS
I bought this comm lathe off ebay

https://www.ebay.com/itm/285846016683
Screenshot 2024-05-16 at 11.21.57 AM.png
I don't know much about it but it looks like a stock motor lathe. Does anyone know the model, or have a link to instructions on this lathe or type of lathe?


Is there a piece missing that connects the drive motor to the comm to be cut? Is there a reasonable replacement?
Is the bit something that has a standard replacement?

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Thu May 16, 2024 3:35 pm
by 1911Colt
Just looking at the pic, I would guess that you need a pulley for the motor you are cutting (it would go on just like a pinion gear) and an o-ring/drive belt to go around the pulley on the drive motor and the missing pulley.

Here is an artist's rendering of what I think you need :lol:

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Thu May 16, 2024 4:01 pm
by 1911Colt
Looks as though you might have a Trinity RC4107.

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Thu May 16, 2024 11:52 pm
by JosephS
This will take a bit of work to get going the lathe works well in the axis along the motor. However the mechanism that is supposed to hold the cutter against the com does not seem to hold it's position properly .

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Fri May 17, 2024 10:08 pm
by JosephS
Turns out there was a missing e-clip. I was able to snag one from the handle. I don’t have the pulley yet so I took a dead motor from my pile and made it a sacrifice. Since it didn’t run at all before not much is lost
IMG_4287.jpeg
Obviously not awesome, but if it runs at all that would be great.

I may try and take some more passes. I am not sure how I made the two deep grooves

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Fri May 17, 2024 10:24 pm
by RC10resto
Are you using the Sharpie trick?
Hit the Comm with a marker before you cut.

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Sat May 18, 2024 12:20 am
by RC10th
And don't stop mid pass, maintain a continuous and constant speed for each pass

Oh, and always make sure the tool carriage is on the load side of the feed screw when you cut.

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Tue May 21, 2024 1:04 pm
by JosephS
I took another pass at the same motor. I cleaned it up better, but there are still issues with it. However this motor doesn't spin freely without brushes and springs in it. All my other motors have some degree of spin. I wonder if there is something more seriously out of alignment.

I have 2 other fixed stock motors, an original slot machine and a chi-town-hustler and I can't seem to remove the brush hoods. The post the springs mount to doesn't seem to be a screw. Does anyone have guesses on those?

Re: Vintage Trinity Commutator Lathe (for stock motors)

Posted: Mon May 27, 2024 10:52 pm
by Frankentruck
A lot of motors have spring posts that are not removable. They basically are a rivet style attachment. The earlier stock motors were not intended to be disassembled for rebuilding, so many have permanently installed spring posts. The one on the right in this picture was broken off.
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1000011193.jpg