issues with motors blowing

colecaswell

Member
Messages
5
hi,

our 2wd ruckus is having an issues - it keeps blowing up motors.

The problems started when we blew the speed controller - frayed wire where the battery connection occurs got wet. After the blow speed controller we went to the local hobby shop and purchased a new one. Post repair the truck worked great - however about 3/4 through the first battery it suddenly died - smelled hot etc… We took the truck back to the hobby shop and concluded that the motor had blew. We purchased a new motor (brushed original replacement) About 3/4 of the way through the first rip on this new motor there was a puff of smoke and the truck came to rest. motor was super hot and the wires to it had started to melt.

When we first replaced the speed controller it seemed our truck was the older version and they sold us a speed controller for a newer ruckus. could this be our problem?

New to RC so insight with problem solving is limited

Any help solving this would be awesome - we are traveling out west - away from the hobby shop that sold the parts.
 
One thing you must remember is the motor determines the amps, and the amps depend on the load/needed torque. If you understand this, you will realize the ESC really can't kill the motor.

So the motor is drawing too many amps, and the amps are cooking the motor. Why? first thing to look at - take out the motor - or at least remove the pinion, and check that the drive line spins free. If you spin the rear wheels, the whole driveline all the way to the spur should spin free for several seconds. If not, tear it down and check for dead bearings, binding drive shafts, gears with gunk in the teeth, etc.

If all that looks good, you may need to get a new pinion with 2-3 fewer teeth - this will give the motor a bit more mechanical advantage, and lower the amps. It will also lower the top speed by a bit.

Worth noting - driving in grass, sand, and similar will heat up the motor. Dropping pinion size is a good idea if this is your normal driving conditions.
 
Thanks for the help and tips!

I did as you said - and removed the pinion - wheels and drive line spin well for about 5 seconds with a push of the hand - no friction or binding.

we mostly drive on hard packed dirt or pavement, both motor failures occurred in these conditions. I will look into a smaller pinion - but do not understand why the truck worked well for years with the one we have and now it is blowing motors because of the tooth count.

Could anything else be amiss - or causing the issues.
 
If the driveline is spinning free, the only other two options are 1- overloaded motor, or 2- bad motor. The ESC can't push more amps to the motor than the motor wants/needs, so I don't think that is an issue. Bad motors out of the box are rare, but it happens.

Oh, another thought, one the subject of "got wet" - my cars get wet all the time. Frayed wires at the connector should not cause an ESC failure. BUT - if your tires filled with water, then the load on the motor goes up, then the ESC is getting worked harder than normal supplying the extra amps to the motor, and Poof! If this happened, then chances are your tires still have mud/water in them, so there is still extra load on the motor, Poof!

What happens - the stock tires have Vent holes in the inside of the rim. When you run in water (or sand or loose dirt) that hole will suck water/dirt inside the tire, where it stays. Tires get heavy and out of balance. The fix is easy - first put some tape over the hole in the inside of the rim. Second punch a hole (or several holes) in the rubber of the tire, right in the center of the tread. I use 4 holes, evenly spaced. Mount up the tire on a drive axle, hold the car up, and give it throttle - water and dirt will come out the holes in the rubber. Let me find a youtube on how to vent the tires... I use a small brass tube in a drill as a hole cutter. Drill bits don't really work.

 
Great - ill give the tire drain holes a go - on initial inspection the tires feel fine - when you squish them air comes out etc... feels empty on the inside. Will look up a video - but i think i get your description of how to make the holes.

One thing with the ESC that i am still worried about is that I may of been sold a new ESC for the new ruckus with a brushless motor - If this is the case - could it cause this problem. Is this something i should look into further?
 
One thing with the ESC that i am still worried about is that I may of been sold a new ESC for the new ruckus with a brushless motor - If this is the case - could it cause this problem. Is this something i should look into further?

Just so I am sure I understand your question here, are you concerned that you may have an incorrect pairing of brushed/ brushless between the ESC and motor? If so, it would be very obvious if you had. A brushed setup uses two wires to go to the motor, a brushless setup has three.
 
A lot with the above suggestions, make sure your gear mesh is correct. If the pinion is jammed against the spur it will cause excess wear and load on the motor.
 
If so, it would be very obvious if you had. A brushed setup uses two wires to go to the motor, a brushless setup has three.
That was one of my concerns - seems it is not an issues - only have two wires.

Ill order and new motor and go through all suggestions mentioned above.
Thanks!
 
Thanks for all the help - new motor and a smaller pinion are on the way. I have a much better understanding of the set up now - very appreciative of the help on this.

Also vented the tires yesterday and there was a decent amount of sludge in there - thinking that was the major issues. Should have it going by monday...
 

Latest posts

Members online

No members online now.
Back
Top