A wandering into motor rewinding - Printable Version

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A wandering into motor rewinding - dazee - 7th-Apr-23

I have recently been cataloging my collection of cars and bench marking them so I have some figures to refer to when I spend a bit more time on tuning.  For this I have decided to use as one objective method the time each car records for a 50m distance @10v, and then later the best times for home track and club track.  If anyone interested Tamiya makes a nice little speed tester for their Mini 4WD cars and I adapted this for slot cars.  Can either measure speed on km/h or time to cover a set distance.

While doing this one of the Carrera DTM cars decided to give me a face of white smoke which in turn got me an ear bashing from Mrs Dazee....
After testing the car with a new motor and everything good, I decided to see if I could fix the smoked motor instead of using a nice new one.  Reading a few posts across the web, I got alot confused and then just followed some reckless advice to just do it and expect to fail the first 6 times!

I dutifully took the motor apart, making notes on turns in the wire, direction etc and ordered a couple of small spools of enameled wire.  .1mm and .26

The Carrera motor wire looked the same as my new .1mm spool so I used that first, as I also order the longer quantity for that too and thought enough to make a couple of mistakes.  The original motor having 187 turns of wire on each arm, I rewound with the new wire to 150 turns - ran out of fingers and toes for counting at this point...

The rewound motor ran, but got hot pretty fast.  At this point I was not sure if this was due to the fewer turns I used, or that I took a real close look and possibly botched ones of the arms enough to have a short.  So took it all off and tried the larger wire.

.1mm to .26mm does not seem like much difference, but heck it meant alot fewer turns.  I was able to get 45 and that was it!
Test running at 6v and 8v was no issues at all.  But when trying 10v my test power supply choked, so I went and got my track power to continue testing.  At 10v it drew just over 2A but ran happily and fast - a time only bested by a 30k motor I have.

Happy enough to go test this car further now and also maybe look to get some more wire stock in different sizes to try some more down the line.

Nothing burst into flames, so I call this first step a success!

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RE: A wandering into motor rewinding - munter - 7th-Apr-23

Glad you got some success.
Maybe you could find out about the SWG gauge numbers of the wire you used? Obviously it is not metric but in old school rewinding it might give some of us previous rewinders a point of reference.

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RE: A wandering into motor rewinding - dazee - 7th-Apr-23

Checks packets it arrived in.

The smaller guage one only says .1mm jumper wire, no other clues.
The larger one says 2UEW which seems to be a coating reference not a guage size. 0.26mm x 20m

Packets are no good, so hello google :)

30 guage for the larger wire, 38 guage for the smaller.

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RE: A wandering into motor rewinding - Kevan - 7th-Apr-23

Following.

Any pics on the process for other wannabe motor winders please 

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RE: A wandering into motor rewinding - dazee - 7th-Apr-23

Let me see if this works, I took a bunch of pictures and put it all down in OneNote as I went.  If this does not work I will try and put together here later.

Should be a PDF export of the document in this posting.

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RE: A wandering into motor rewinding - Kevan - 7th-Apr-23

I'll check it out when I get home

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RE: A wandering into motor rewinding - chappyman66 - 7th-Apr-23

Lots of articles about rewinding, especially if you read the old magazines.
They run hot because it pulls more amps with the larger gauge wire.  Also, since people aren't as reproducible as machines, balancing the arm after winding will help. Consider the air gap to the magnets, shimming them with tape or shim stock can help also.

This is why people melted commutators and endbells back in the old days.  ?

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RE: A wandering into motor rewinding - chrisguyw - 7th-Apr-23

Hello Dazee,...good to see a few folks trying to repair/rewind armatures  .

If in fact your stated figures are correct (I assume they are),......45 turns of 30 gauge wire will not be a long lived armature given  the magnets/brush gear in the Carrera motor, evidenced by it drawing 2 amps free running........45T x 30 gauge is considerably more aggressive than  the 65T x 30 gauge armatures found in many of the entry level commercial track (50K ish ) motors , and these motors have considerably better magnets/brush gear/comms.

That said, experimenting is a lot of fun, and I applaud you for diving in.

Cheers
Chris Walker

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RE: A wandering into motor rewinding - dazee - 8th-Apr-23

Thank you Chris,

always finding more aspects to the hobby and still enjoying the voyage of discovery.  I guess I am currently very bad at winding as with my current level I can not imagine being able to get 65 turns.  A target to aim for!

The next step is going to be seeing how this car runs at the club track - my track is currently tore down as I go into a rebuild with smaller footprint.  First step is rebuilging my tables smaller and a little prettier.  Anyways I digress.  Will be at the club track today to test it out.  I am not expecting great things for a 2nd attempt, especially if 45 turns is an aggressive motor and the club track is short.

So a general question.  When people are doing slot car drag races, would they normally be winding their own motors?  I am assuming this is the case but finding information about how people prepare their cars for racing is a little challenging.  I guess for a reason :)

I have some 0.19mm wire on the way for the next attempt.  I figured half way between the 2 sizes tried so far will be a happy medium.

Slot car motors and parts are hard to come by here.  I can get Plafit motors at the club but that is it.  Any other motor I have was shipped by Pendles from the UK.  If I can get better at rewinding I can take advantage of the parts from the Tamiya Mini 4wd market here - at least to my way of thinking.

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RE: A wandering into motor rewinding - chrisguyw - 8th-Apr-23

(8th-Apr-23, 12:35 AM)dazee Wrote:  Thank you Chris,

always finding more aspects to the hobby and still enjoying the voyage of discovery.  I guess I am currently very bad at winding as with my current level I can not imagine being able to get 65 turns.  A target to aim for!

So a general question.  When people are doing slot car drag races, would they normally be winding their own motors?  I am assuming this is the case but finding information about how people prepare their cars for racing is a little challenging.  I guess for a reason :)

Hello Again dazee,.................Most, if not all of the folks involved in Drag racing (and also the top levels of circuit racing) , use custom armatures from Manufacturers such as,...Pro Slot, Koford, PK etc., as these use state of the art production methods/machines, parts, and balancing devices,...most of which are not affordable to the average racer.
As well, these manufacturers have vast experience in producing armatures gained over the 50+ years that many have been producing them, ( I used PK arms. that they supplied to me starting in the mid. 70's) and these manufacturers  armatures will considerably outperfom  (to put it mildly) and outlast, any "homemade" armature..no disrespect here  ,......and please keep winding  ).

Regarding wire size/gauge,.......A 30 gauge wire is far too aggressive for any commonly produced/used  FF-130 motor............their magnets are too weak, the comms are not up to the job, and the brush gear is woefully inadequate,............I would try to purchase some 32/33 gauge wire and load on 130 to 150 turns,.........this will still be a very very very quick motor, and will push the other bits of the motor to their  limits, or likely above !!

Here is a pic. of a ProSlot arm,.....drill blank shaft, heavy duty diamond trued/epoxy thread wrapped comm., powder coated, laminations ground, wound/epoxied, and dynamically balanced. These type of arms come in a very wide range of stack lengths/diameters, winds, and comm advances,.......some are "spec" arms. (Gp 12/15/20/27/ S16D etc.) ,  while some are "open". The average price of a current "open" circuit or Drag motor is in the $450/500 US range, and these need frequent and costly rebuilds.

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