Repair Futaba MC 210CB ESC

[whyme]

I am trying to restore my old RC10 #6011 from the early 90s. My servo control works fine. When I power on the car, the wheels give a small jolt, so I think the motor is ok. When I try to throttle, the Futaba ESC makes a buzzing sound and the motor doesn't react at all. I tried checking all my connections. What's the best way to know if the ESC is toast? Are their guides for opening them up and fixing them?

Thanks

[TRX-1-3]

You could check the "scans" archive and / or the "vintage electronics" forum here. There may be an owner's manual for that particular ESC. There may be an initial adjustment needed or if your battery pack is not charged up there may not be enough juice for the ESC to "process" to the motor. But if your motor twitches when you turn everything on, it might be a positive sign. That's not much help but maybe someone else with more expertise will add their 2¢.

[radioactivity]

You might try
https://www.manualslib.com/manual/378363/Futaba-Mc210cb.html
That should get you started.

Chuck

[jwscab]

the good news is that something happens. That probably means it's fixable. As to what's wrong, you would have to run some tests and be a little knowledgeable regarding the operation of the esc and electronics. It's not super easy, but it can be done.

The very first test is a visual and odor test. yep, odor. Burnt electronics have a very specific smell to them. So open the case, and look for anything that looks charred, missing, or melted. Should be easy to spot, but sometimes the chip/transistor packages look ok, but the text etched on them might be discolored. Then do a smell test, sniff around to see if one area of the board smells stronger than another. Check the PCB(circuit board) for signs of shorts or opens, usually again, discolored, or stuff that looks like an arc occurred.

while it's out of the enclosure, apply power being super careful not to short anything, and tape off the motor wires. if there is something still shorted, it will heat up quite quickly so feel around. in normal operation sitting idle, the electronics should get no warmer that maybe slightly above room temp. Anything hot will be immediately noticeable.

take some pics of the guts, that will be helpful to troubleshoot from here. Also, it will be useful if you are good at soldering, since any broken parts will need to be replaced.

[whyme]

Actually, it seems to be the motor that is the problem. Any advice on opening a Mr. Outlaw Reedy Modified Brush motor? I'm not finding the screws that take off the cap.

[radioactivity]

whyme,
Let's start by asking why you believe it's the motor.
There may be several things to do before opening the motor.

Have you tried a different motor?
Have you completely removed the motor and applied voltage to it to see if it spins in the correct direction freely?

Chuck

[whyme]

It tries to move, but it seems to not move too smoothly. I don’t have another motor.

[radioactivity]

whyme
Is that with the motor completely disconnected from the speed control and using a good battery of known voltage?
You can test with a new 1.5v battery if your 7.4v battery is questionable. It won't spin very fast but it could give an indication that the motor is either good or bad.
Eliminate the possibility of any bad connections. Check the endbell of the motor as it will be marked + (positive) and/or - (negative).
If you want to isolate the problem you must individually test each item, the motor is the easiest to check.

Chuck

[whyme]

Oh, I bought I new 7.4v battery. Can I connect that directly to the motor?

[radioactivity]

whyme
Before you apply a full 7.4v try something smaller. If the motor is bad, that is probably way to much power to put through it. If it is OK it will spin like a whirling dervish, way too fast! Slow and easy does it.
Disconnect it, rotate the motor in the correct direction with your fingers. Does it turn freely? Does it feel gritty, scratchy or just plain wrong?
Put a lube on the bearings, both ends of the shaft.
You can carefully, carefully remove one or both brushes by unclipping the brush spring and visually checking the brush for wear.
When you reinstall the brush put it back in the exact way it came out!!! The brushes wear in the direction of rotation. Putting it in backwards will probably chip the end of the brush and will not do the commutator any good at all.
If after checking for bad bearings you carefully remove a brush, look carefully at it for wear, chips or anything odd looking. Also look at the commutator and check for dark or burned marks.

The top pic shows a brush that is used but not completely used up.
The bottom pic looks into the motor to show the comm.

The least aggressive cleaning would be a Q-tip with alcohol placed down the brush hood and rotating the motor by hand.
These brushed motors need to be cleaned and lubricated regularly.

Chuck

[whyme]

Thanks for the tips. I got the motor to run with a 1.5v battery. I sprayed down the inside with WD40 prior to that. It didn't seem possible to take the cap off the brushed motor and take a look inside. The metal casing was crimped on to the cap. Anyway, I guess the motor is fine.

The problem is the Futaba MC2010CB ESC. Not sure if that can be repaired. A few online tutorials mentioned soldering new chips. I don't think I'll be able to do that. I haven't tried prying open the casing yet.

[Chewbacca]

Did you try swapping the channels on the receiver?

-> Steering with throttle and vice versa?

[whyme]

Yeah, I did that. Same problem and steering worked fine.

[jwscab]

if you aren't familiar with working with electronics, you might be better off just picking up another used or new one for cheap. There are lots out there and the futaba one is not a rare or unique model, so unless you have a personal attachment to it, its probably not worth it.

[radioactivity]

whyme

The "swap the control wires" chewy suggested is a good idea and may be saying the motor could still be the problem.
Spraying the motor with WD40 will not solve a brush to commutator problem.

I would resist the temptaion to pry open the moter right away.
Did you check the brushes and the condition of the comm? You don't need to open the motor to check the commutator. Use a flashlight to look.

WD40 is also a poor lubricant for the bearings. Use only one drop of motor oil on each bearing after any cleaning.
When the motor is running in the proper direction on 1.5v do you see many sparks from the brushes? If so the following can help.
If the brushes aren't chipped or broken, a thorough wet cleaning would be a very good idea, but never on a brushless motors.
There are several videos on youtube showing how to either wet or dry break-in and/or clean a motor. These methods, particularily the wet method, can be used to clean a motor.
This will help seat the brushes as well.
I don't run a motor using the wet method for much longer than 5 minutes when cleaning though. Thoroughly dry, then lubricate the bearings. A 1.5v will be good battery for cleaning.
When we raced BITD nearly all the racers would wet clean their motors every race.

Chuck