burned up a brand new tekin

[Tufftf2]

been a long time reader but this is first time posting....you guys got a great thing going on here and have helped me out alot!
so like the title says...i just finished a build. started a scx 10..now has custom chassis full metal gear trans...87/17 gearing.. with hr drive shafts...ssd d60 axles with od/ud gears and vanquish stage 1 with vvd's..not a pig by anymeans but not light either..sidewinder 3 and a tekin 45t hd..on its maiden run was doing pretty well, went swimming a few times but clean water no mud...ran it for about 20 minutes and on the way back to the truck the motor let the smoke out...took the motor off and checked for binding in the drive line nothing to speak of there. took the motor apart and the wire is burnt at the comm...any theories would be appreciated..would like to get it back on the rocks but hate to burn up another motor
thanks in advance and sorry for poor spelling and grammer if that bothers you...

 

[JatoTheRipper]

I would contact Tekin. They will take care of you if they deem it to be an issue with the motor. Although you did get it wet and I'm not sure what their policy is for their brushed motors.

 

[Tufftf2]

tradded for the motor nib...think they would still help?
but the real question is is there anything i overlooked to burn it up or did i get unlucky with a crap motor?

 

[Ditchrat]

Couple things to consider, what voltage batteries, was the motor running hot the whole time? You said no binding once the motor was removed, however I have miss spaced the pinion and caused motors to overheat, is this a possibility?

Are you spacing your pinion correctly?

Did you break in the motor? Failure to break in brushes correctly can cause a high draw which will result in heat. Once you start over heating the winding a short may occur.

Other then that a burnt wire at the comm, could indicate a poor connection, resulting in excessive heat or arcing. Both of which may be the cause of the burnt wire. Or the burnt wire could be the weak point and just the symptom.

Sorry I can't give you a definitive answer, rarely can you identify a smoking gun, but at least you have something's to consider.

 

[Tufftf2]

Im failry confident in the mesh i had and i didnt "break in" the motor but ran it pretty easy around the house for 30 minutes or so before i hit the rocks..ive been told those tekins can handle 4s for a bit but i was running 3s..im begining to think it must be the 1/2 gallon of water i squeezed out of the tires....always run sealed tires or closed cell foames the tire weight never crosses my mind until i had it torn down on the bench...

 

[Ditchrat]

My $10.00 motors run all day with soggy tires, I doubt the tekin couldn't handle that.

 

[imthatguy]

No matter how clean you think the water might be, it isn't.

 

[Hydrocarbon92]

A $10 motor probably has a much harder comm & brushes, so likely less amp draw. The same amount of dirt on the comm would lead to a lot more arcing if there's more amps being pulled and more damage with softer parts. It's like knock in an engine - an econobox will survive but a lightened 13:1cr race engine will blow up in seconds.

 

[JohnRobHolmes]

My $10.00 motors run all day with soggy tires, I doubt the tekin couldn't handle that.

A $10 motor probably has a much harder comm & brushes, so likely less amp draw. The same amount of dirt on the comm would lead to a lot more arcing if there's more amps being pulled and more damage with softer parts. It's like knock in an engine - an econobox will survive but a lightened 13:1cr race engine will blow up in seconds.

Sealed can style do much better in water. Not only do they draw less amperage, but there are no brush channels to get jammed with silt.



Did all of the wires burn, or just one segment? If just one, it is a manufacturing defect. If the entire thing burned up, it is more likely that something got inside.

 

[Ditchrat]

All true, but i dont run sealed cans. The point really was is a cheap motor can handle water logged tires then chances are a better motor should also.

 

[Tufftf2]

Did all of the wires burn, or just one segment? If just one, it is a manufacturing defect. If the entire thing burned up, it is more likely that something got inside.[/QUOTE]

Looks to me like they all lost their insulation at the com.
If there is stuff packed between the com bars is that what caused it?
I geuss its a chance you take everytime it gets wet but ive run a 35t tekin underwater alot and never had an issue its just hard to belive i got so unlucky in 20 minutes of run time and only being in the water less then 5 minutes.

Its an honor to hear from the man himself on my thread. Thanks for chimming in jrh!
Was currious if i could buy one of your 5 slot armatures and use it in this almost brand new tekin can?

 

[imthatguy]

My first run in the wet with my TRX-4 resulted in exactly this ALMOST happening. So yeah, it can happen.

 

[JohnRobHolmes]

Looks to me like they all lost their insulation at the com.
If there is stuff packed between the com bars is that what caused it?
I geuss its a chance you take everytime it gets wet but ive run a 35t tekin underwater alot and never had an issue its just hard to belive i got so unlucky in 20 minutes of run time and only being in the water less then 5 minutes.

Its an honor to hear from the man himself on my thread. Thanks for chimming in jrh!
Was currious if i could buy one of your 5 slot armatures and use it in this almost brand new tekin can?

If you have stuff packed in the comm, thats a good clue that it was contamination. Running in water really is a luck thing. Sometimes ok and sometimes its quick failures.

You can throw in any of our 540 armatures into your Tekin. 5 slot Crawlmaster included.

 

[Tufftf2]

Good to knowif tekin wont help me out (wich i would completlty understand) 16t crawlmaster amature it will be. Would you suggest new brushes to? The old ones have hardly any wear on them. Thanks much for the reply.

 

[Hardcoretam]

I run rebuildable motors all the time but i try and make sure the water looks crystal clear first and if i start kicking up dirt from the bottom then i get out of it pretty quick
Only cheap chinese rebuildables i use though and usually give the comm a clean with an eraser and oil the bearings every now and then.

87/17 gearing is quite long if running tall tyres and on 3s. Did you check the motor temps at all when running before it died?

 

[Tufftf2]

I thought i would be safe on 4 .75 in. Tires....the motor wasnt overly hot while it was smoking lol....there was some junk between the comm bars and from what ive learned from previous posts im guessing thats what killed it.....

 

[Hydrocarbon92]

Anything that causes the brush to push away from the comm will cause arcing, and gunk in the gaps can act as a bump/ramp. A little arcing at the edge of the segments is normal but too much arcing causes high comm heat. That's why the insulation melted around the comm.

 

[Tufftf2]

Never spent much time in the water guess ill stay out all together now....or buy a titan can for the occasional romp....and just so everyone knows tekin has phenomenal customer service...very quick responses curtious and to the point....ultimately they wouldnt replace the motor becouse i couldnt provide original receipt but where still willing to sell me a new unit at almost 50% discount....only time ive ever needed their customer support but was a good exsperiance!