rewinding motor arms?

[Tadracket]

I was reading on theshreves.com where a motor rewind was attempted. Sounds like it did not go so well. I am a tinkerer by curiosity and would love to rewind one of my old motors. Anyone here ever do it? If so, what are the tips and tricks and what kind of equipment would I need?

[mikedealer]

there is a LOT to hand winding motors, even if you get it right you will need to balance the armature or the thing will shake pretty bad, along with getting the length of wire on all winds JUST right.. i think big jim's book cover some of it.

[Tadracket]

there is a LOT to hand winding motors, even if you get it right you will need to balance the armature or the thing will shake pretty bad, along with getting the length of wire on all winds JUST right.. i think big jim's book cover some of it.

I got no problem with the fine details. Explain to me about Jim's book. Is this the guy you all refer to sometimes when discussing Checkpoint (I think) motors?

[mikedealer]

big jim wrote the rc motor bible, designed a ton of motors, died a few years ago, and his book hasnt been published since, it pops up on ebay once in a while but all the important info is here in this thread
http://www.hobbytalk.com/bbs1/showthread.php?t=126994

the book is "very" repetitive as far as info goes, but there is a lot of good info in it.

[Eau Rouge]

Big Jim's book has some good info in it, but isn't worth the paper it's printed on. You can find all of the information on the HobbyTalk forum that Jim posted on, as well as the RCcars.com forums that he fielded before he passed away. That book is just cut & pasted info from those forum posts, so that's why it tends to aimlessly wander in circles with the technical stuff in it.

It is NOT possible to rewind a motor arm, nor is it worth it. First, the tools and equipment required to wind a motor are very costly and very specialized for building motors. The machine for balancing the arms alone is $6000. Second, the arm has the windings epoxied and welded to it, and is not suitable for use after the windings come apart, nor would you want to start with a used arm blank with a smaller comm. Third, a new arm is less than $40 for a perfectly hand-wound, balanced and trued arm, and there are still a handful of fantastic motor builders like Todd Putnam who will custom wind you any motor and arm you could possibly imagine. And those guys have decades of experience under their belts, and could wind these things with their eyes closed. They were also taught by guys like Big Jim.

You could wind your own motors, but you could also go and chop down your own rubber trees to make your own tires. This is one of those instances where it's not practical to do everything yourself.

If you wanted to change a stock or machine-wound motor's performance, you could open the comm tab with flush-cut dykes, cut the wire at the tabs, unwind wherever you don't want, clean the flux and resin off of the wires and solder back on under the tab. But again, I'm not sure why you would want to when arms (and motors) are so cheap to buy new.

[Bugle]

I had a go at it because I bought some crappy cheap Orion mod motor which had an extra wire wrapped around 1 pole for a few turns then just poking out. Was slower than a 540 and created more heat than an overgeared stock so I unwound it. Only wire thickness I had was good for a 10x3 so I did that. Just soldered the new wires to the tabs, no balancing just tried my best to wind it neatly. Anyway it ran really well for a few minutes then it threw a winding off, out of the 3 wires one pulled out at the end as my soldering wasn't good enough but i'm sure it could be soldered and last.

[Tadracket]

I saw the article and just thought that would be a fun project. I cut winds out of a 540 mabuchi years ago and was......unpleased by it's performance (smoke and flames ).

No real reason to do this other than curiosity. Sounds like I have enough projects going on that I can leave this one to the pros .

Thanks guys for the comments.