Sparks from 27T Motor

[questionare]

Hi guys,

I bought a used SCX10, and it came with the stock 27T motor.

Today I noticed that there are sparks shooting out from the motor when it is in full throttle. Inspecting the motor more closley, I noticed that there is broken brushes; I only found 5 complete ones, and the others are completely broken; as in the below pictures

What would cause this, so I can avoid it in the future, the gearing is the stock one 20/87 I believe.



Thanks in advance,

[TacoCrawler]

Originally Posted by questionare

I noticed that there is broken brushes; I only found 5 complete ones, and the others are completely broken; as in the below pictures

what does this statement mean ?

there's only two brushes per motor !?

pictures wouldn't load for me

things that can cause damage to brushes...

1. heat (over geared/full throttle-jack rabbit starts)
2. impact (jumping houses)
3. contamination(debris in motor)
4. commutator run out bad/bad bearings-bushings
5. defectively mfgr'd brushes from the start

besides it's windings... what motor do you have ?

[questionare]

Originally Posted by TacoCrawler

what does this statement mean ?

there's only two brushes per motor !?

Maybe I used the wrong term. I have Axial stock 27T Motor. Now it has two openings, in them, I can see gray plastic 'fins', some of these fins are broken, and some are complete. Is that normal?

If you click on the links, wouldn't they open the images?
http://postimg.org/image/fz0t1j7h3/
http://postimg.org/image/q0bsl4759/

[allanon1965]

Those are blades on the internal cooling fan...lots of times running in loose gravel/dirt/sand will cause them to break off when hit by debris...dont know how critical they are for that cheap motor..sparks could indicate issues with worn bearings which could also cause broken blades from fan contacting motor housing

[questionare]

Originally Posted by allanon1965

Those are blades on the internal cooling fan...lots of times running in loose gravel/dirt/sand will cause them to break off when hit by debris...dont know how critical they are for that cheap motor..sparks could indicate issues with worn bearings which could also cause broken blades from fan contacting motor housing

Yeah, they are the blades.

The motor sometimes gets hot, so I don't know if this is due the missing blades, only 5 blades still available.

I already ordered another one along 55T one; I know they are cheap, however, I am trying to find the best 'T'; then I would get a better one.

For 27T, what gearing is advised, mainly for bashing and crawling. Am not looking for much speed.

Thanks,

[6sharky9]

For a 27t motor try a 16 tooth motor pinion with the stock 87 turn spur gear...A 55 turn will be very very slow and you won't get up many hills or through soft stuff like mud or sand..I don't recommend it personally...if you have to, try a 35 turn but I recommend a 27 turn especially if you are using a 2s battery.

The 16 tooth gear will also help you with cooler temperatures

[k goodrich]

16/87 sounds good... final ratio about 5.5 to 1 is what i like to run.