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Ray
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Hi all one interesting topic came up at our club the other night and that was the running in of motors using a Dremel.

The suggestion is that this trues the commutator without producing carbon deposits and the motors can be run up to quite high speeds.

Anyone tried this?

Regards

Ray
 

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Rich Dumas
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In my experience the motors used in most 1/32 cars can just as well be broken in on the track. Motors used in 1/24th and HO cars can be damaged if you run them at full voltage before the brushes are broken in. I race my cars and I don't have a 1/32nd track, so I run in motors on the bench. Before the brushes are broken in you get a lot of arcing at higher voltages and that is one thing that can damage the commutator. Dust from the brushes can also short the commutator. If you break in the brushes by spinning the armature with another motor there will be no arcing, you can apply enough voltage to the drive motor to reduce the break-in time.
 

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QUOTE (Ratracer @ 28 May 2011, 12:30) <{POST_SNAPBACK}>Hi all one interesting topic came up at our club the other night and that was the running in of motors using a Dremel.

The suggestion is that this trues the commutator without producing carbon deposits and the motors can be run up to quite high speeds.

Anyone tried this?

Regards

Ray
Running in normally beds in the brushes, it doesn't true the comm.
If you want to true the comm you need a lathe.
 

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Like 300 SLR said, - and any method of bedding in brushes involves removing the amount of brush material, regardless of whether current is flowing throgh the brushes.

So the logic the people were working under is faulty. They may have the belief that an absence of "arcing" from the brushes means less build up in the gaps between the comm. segments, but I cannot imagine why it would be physically much different.

It is easy enough to flush the comm. using any of the numerous light solvents sold for this purpose.

You can also run a motor for some while then take it out of the car, drop it in a bowl/can etc of water, and give it 3 or 4 volts. Best done using warm water with a couple of drops of dish wash detergent in it; which is a mild surfactant and will help lift the surface grime of the come faces as well as dislodging the build up between comm segments. You will quickly notice the water go grey with the suspended carbon particles.

When done, drop the static motor in a spot of meths for 5 seconds, give it a shake and leave to dry.

This will also rejuvinate some gummed up motors in which the performance has dropped, but they haven't actually cooked a winding or ruined the brushes as a result of carbon shorting on the comm.
 

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Ray
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Discussion Starter · #5 ·
Hi all thanks for the replies.

300SLR a lathe would be great but our rules do not allow the motors to be opened hence the question about non powered running in.

Thanks slotcrazy I have tried all of your suggestions but am a bit wary of this approach now particularly with NINCO's certainly do not use VOODOO on them any more.

Has anyone tried the non powered running in method just interested specifically in this approach.

Regards

Ray
 

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Hi Ray
Perhaps I didn't make my point clearly (apologies if I've misunderstood your reply)
In the first post it says "The suggestion is that this trues the commutator "
That suggestion is incorrect, running in will do nothing to true the comm
What running in can do is bed in the brushes, which will make the motor run better than brushes which are not bedded in.
Truing up the comm on a lathe would make it run better still, but I take the point that you cannot do that if the rules don't allow it.
 

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Ray
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Hi 300SLR sorry yes did get that important point, I probably used the wrong terminology in my original post. Have you tried the Dremel option for running in or know someone that has really interested to see if this is a viable option or just an urban myth?

regards

Ray
 

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It would be fairly simply to connect two motors with a "spring" if one wanted to do this. I've tried the water system, used WD-40, Meths ( methyl hydrate if you from over there) now I just run them while I do other stuff. Meths for a flush unless they are closed end and then I use the WD-40.

Bought an cheap ultra sonic cleaner for soft brush ( MB slot) motor cleaning with limited success.Still needed mechanical cleaning but didn't have to strip down. (note to Ember. The motor not me)
 

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One petunia in a field of onions
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QUOTE (Abarth Mike @ 2 Jun 2011, 12:06) <{POST_SNAPBACK}>Bought an cheap ultra sonic cleaner for soft brush ( MB slot) motor cleaning with limited success.Still needed mechanical cleaning but didn't have to strip down. (note to Ember. The motor not me)
Thanks for that Mike. Some images I don't need.
Plus I'm rather wary of MB Slot motors having recently had one sacrifice itself to the fire gods. Can't find anything obviously wrong with it under magnification, but it's definitely deader than Elvis.
 

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There are lots of ways of bedding in brushes, as well as the ones described above there are tools to cut the end of the brush to the right shape.
They are all trying to do the same thing - make the end of the brush match the shape of the commutator.
The only way this can be done is by removing material from the brush. It is fairly obvious from this that
1 If it is overdone and too much material is removed, the brush life will be reduced
2 Some brush material is removed, the debris must go somewhere.

So the suggested Dremel method will produce as much brush debris as the other methods. The debris will end up inside the motor unless it is cleaned out, as in most of the other methods.
 

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I just run them for 200 laps or so. Turn the power supply down, put a clamp on the controller trigger, start up the lap counter, and find something else to do for a little while. I've never really tested if this actually improves the performance 'though. Hmm, something to try over the next few days perhaps.

Randy
 

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Nobby Berkshire
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You don't need to run in modern motors

It doesn't make any difference other than wearing things out for no gain or fun whatsoever

Just take it easy for 10 laps and then race them in and save lots of faffing about

Just think of the time you'll save to go out and pick strawberries for the local PYO
 

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The comm must form a thin film of copper oxide for proper operation. The comm is not bare copper!!!!!! You can only form this copper oxide layer by running the motor with power (electron transfer eg arcing) and a certain amount of atmospheric humidity will caise the oxide layer to build up. I cant see what you are attempting to do by running without power? This will not true up the comm and will not cause a oxide film to form. It will I suppose bed the brushes in and the bearings as well.

cheers
rick1776
 

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QUOTE (Screwneck @ 6 Jun 2011, 15:25) <{POST_SNAPBACK}>You don't need to run in modern motors

It doesn't make any difference other than wearing things out for no gain or fun whatsoever

Just take it easy for 10 laps and then race them in and save lots of faffing about

Just think of the time you'll save to go out and pick strawberries for the local PYO


Don't want to be rude (for a change) but what are you basing this classic example of a sweeping generalization on? I've noticed when I break in the cars with clamps on the throttles, the laptimes get better as the car runs. I don't know if the motor is breaking in or the bearings are breaking in but something is feeling more comfortable.

Randy
 

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If you take a look at the running surface of the brushes at stages during bedding in, the changes during bedding in are easily visible.
The improvement in lap times with bedded in brushes are measurable.
Of course those who do without observation and measurement might not be aware of these changes.
 

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Tony Condon
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Blimey
We are on the second page already ,and no one has yet touched on the advantages (or otherwise ) of running in motors underwater .I was assured by one or two well thought of punters on this forum that it was the only way to go
Tried it once on a falcon ,but it still blew up after a couple of hours racing ,but then dont they all?

Cheers tony
 

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Nobby Berkshire
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I'm basing my views on the fact that running in under water, or in any type of oil-based refined liquid, or in maple syrup, or in chocolate sauce makes absolutely no difference whatsoever. The only thing that needs running in are motor brushes and they run in 100% perfectly under normal running conditions. They're only lumps of conductive material and all modern motors have the brushes shaped to the comm already!

C'mon guys, we're talking about little tiny weeny electric motors, not Ferrari V12 engines
 

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Tony Condon
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Hi
While I might be inclined to agree with you ,there is a bit of theory behind running in under water
The problem with un bedded in brushes is that they tend to arc while they bed in .
The arcing will actually burn away little bits of the com especiallly adjacent to the com slots, this in turn means that the conductivity across those burnt bits will always be worse than the bright copper ,and eventually this will cause more arcing and premature wearing out of the com
Running in under water prevents this arcing, and also the water wahes away the carbon dust from the unbedded brushes
thats the theory any way

Cheers tony
 
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