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tulsidas
04-03-2006, 12:10 PM
After burning the first one, thought would be careful with the 2nd. Ran it at low speed for 3-5min when fresh. Used 12T pinion (thot wud help reduce load) never more then a single battery pack at a go, 2 x GPM heatsinks. Must have done 4 packs over a few days at most.

Today half way through a battery pack it jams up. When hitting the throtle can still hear the motor tryin to turn but jamed.

Are these motors so delicate or am I doing something wrong ?. :confused:

Can these be recovered ?

over_powered_rookie
04-04-2006, 06:43 AM
if you can hear the motor trying to function,id say you have some debris in the can,or something jamming the pinion gear...take a good look and let us know what you find

tulsidas
04-04-2006, 12:07 PM
I did not find anything blocking the pinion or dirt inside the motor can. After removing the motor from the car, I tried turning the shaft and found it to be hard to turn and seems jammed.

I then opened up the motor and pics below show

1a) the motor shaft with bluish stuff which seems to have melted onto the core windings
1b) A white mark on one of the metal fins on the shaft. This was present on the motor when brand new.
2) The commutator with black lines
3) The brushes on motor lid
4) The motor can from the inside.

Observations
-----------------

If the motor is assembled back with the lid a bit loose the shaft turns smoothly. Also tried by connecting to battery pack and the motor seems to run well in this state.

However if the lid is pressed down into the can, the shaft feels jammed (like before opening the motor up).


Analysis
----------
Tried with shaft only on the lid, pushed back against the lid, the shaft turns smoothly

Tried with shaft only in Motor Can, the shaft turns smoothly.

only when lid closed and pressed down the shaft jams.

Conclusion
----------

I am suspecting either the shaft fins are out of alignment or the magnets in the motor can.

Your inputs most appreciated.

crymynal
04-04-2006, 12:10 PM
Something doesn't sound right. I launch my ST off 6 foot skate park ramps and spines with no problems. I agree with OVR, check to make sure you don't have any small debris in the can or even in the center diff.

*EDIT*

We posted about the same time. Your brushes look chipped. In the one of the pictures the poles have white marks which would make me think the comm is not rotating smoothly but in an oval direction.

Where are you getting your motors from? Perhaps they are bad knock-offs!

tulsidas
04-04-2006, 03:19 PM
It came in kyosho packing and got it from a Kyosho reseller shop here in Singapore.

bermbuster
04-07-2006, 11:38 AM
looks like something is out of round.....you didnt hold the motor can in a vise or drop it? The other reality is some poor QC let the motors through. The shop got those motors.......Im curious as to how much did you pay for them?
In the US you can find them for $12-$15. If you are down on the x speed try a rocket 400 ($9) from www.hobby-lobby.com

46u
04-23-2006, 05:25 PM
You do not think maybe you have an ESC problem? I have never had a problem with my X speed.

arsehoyle
05-14-2006, 08:22 PM
The blue stuff is a resin based adhesive, normal for an electric motor.
The white mark on the armature is also normal. Manufacturers often use those types of markings for reference when winding motors and such.
The black marks on the comm are probably a result of excessive arcing from binding, leading to too much load on the motor. (you can carefully clean that up with a pencil eraser if you dont have a comm lathe.)

Based on the information you've given, I'd say your problem is either a bushing that isn't pressed in straight, motor shaft is bent or endplay is too tight. There are other possibilities but we'll start with these. You should be able to visually check the bushings to see if they're seated properly and check the hole inside for signs of uneven wear. With the motor assembled endplay can be checked by simply grabbing the shaft and pushing and pulling it (in the direction of the shaft of course), in an unmodified Xspeed I'm seeing about 0.015" (a bit less than 0.4mm). If endplay is too tight while the motor is cold it'll bind when it warms up. Try pulling one of the shims out (preferably on the pinion side) and see if that helps. Make sure to keep at least one shim on each side, as they act as a thrust bearing (you may have to find some thinner shims). If you have to pull a shim from the brush side make sure the brushes don't wind up too close to the motors windings.

Just some guesses based on your description. Hope it helps.

AkRacingProducts
05-29-2006, 04:42 PM
Also break in the brushes. Just run hte motor at 1/4th throttle for a minute with no load on it, wait for it to cool, and do it again. Do this 3 times to properly seat hte brushes.