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I'm trying to rebuild this Diamond 12 turn double and I can't figure out how to install the armature. I have brand new 1/8×3/8×5/32 ball bearings in it. But the armature won't slide in nicely. Yes I have tried freezing it. Am I just supposed to use bushings or is there a truck to this. Also, what screws am I supposed to use to hold down the end bell? Is this even the correct armature for this motor? What is the meaning of life? Who knows?! Who cares?!

Normally the armature just slips in the bearings....

I don't think that is the correct armature as it looks like a single wind instead of a double wind.

RC10th wrote: ↑Tue Jun 03, 2025 3:25 am Normally the armature just slips in the bearings....

I don't think that is the correct armature as it looks like a single wind instead of a double wind.

Hmmmmm.... interesting. I'll look through the stock of armatures that came with the lot to see what I have that might fit the bill. How should I tell double/triple wind from a single wind?

Look for how many wires are wrapped around the armature crown, just be careful not to count on the section where they overlap.


This one is a Triple - 3 wires


This one is a Quint - 5 wires

I have had a few that had nicks on the shaft, preventing them from going on smoothly. Deburring the shaft with a mini-file usually works.

If I have an armature that doesn't go into a bearing, I hold one shaft end in a drill, spin it up, and polish the other shaft end with 500 or 1000 grit sandpaper. Usually it's the pinion end that needs the cleanup.

That armature looks like a stock motor armature. Lots of wraps of wire on it. This is the armature my Diamond has and I think it's correct.
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Frankentruck wrote: ↑Tue Jun 03, 2025 8:39 am If I have an armature that doesn't go into a bearing, I hold one shaft end in a drill, spin it up, and polish the other shaft end with 500 or 1000 grit sandpaper. Usually it's the pinion end that needs the cleanup.

That armature looks like a stock motor armature. Lots of wraps of wire on it. This is the armature my Diamond has and I think it's correct.
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Thank you! I see now that I am missing a piece or two. I'll definitely be digging through some boxes to see if I can find the rest of the pieces to reassemble this guy.

A non-metal spacer is used to prevent the bearing / bushing from contacting multiple segments of the copper commutator and short circuiting the motor. OEM are usually a thin brittle fiberglass washer. When I don't have one of those, I use one of these Digi-Key #4 fibre flat washers.
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Small #4 metal washers (brass preferred) are used at both ends of the armature for any additional shimming needs. It should have some ability to move within the can. The neutral point is set by where the can magnets hold a non-shimmed armature in an assembled motor.
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Phenolic + small brass. For example: https://www.shoppscr.com/motors-setups-and-motor-parts/armature-spacers?srsltid=AfmBOorzdgN-8dqCam7GFECsI9Ed1snvag8-T7szf6OoQu4NwiilvhnZ

Thank you for all the help. I found 5 random armatures in the box of many things. I think the one on the far right is our culprit. It's double wound and has "12" written on it. If anyone cares to ID the other armatures, feel free.

That might be a 21 on it. I think 2nd from the right is the one. Err scratch that, it's a single. Good luck.

Hmm, that's a tough one. Maybe it's none of those

Oops, double post

RC10th wrote: ↑Tue Jun 03, 2025 8:20 pm Hmm, that's a tough one. Maybe it's none of those

Darn it! Well it's gonna be one of them unless I find the right one sometime soon and it might as well be a double turn, regardless of which double turn it is.

Like Frankentruck said I thought it was second from the right as well due to the groove in the rotor from his picture, given his hasn't been tampered with previously. But then I saw he said it was a single so I looked closer and it does look like a single.

A single will give you more torque than a double at the expense of a little RPM.

If you want the most power look for the one with the largest wire and the one that appears to have the least number of wraps around each segment.