RC10Talk - The Net's Largest Vintage R/C Community

Here's a question for you motor gurus...or at least, you vintage motor gurus! I'm restoring all my old vintage motors (Kyosho 480 Gold and 360 Gold) and this particular unknown custom-built motor. I can't tell you much more about it other than it's likely a 4-minute motor--which back in those days, was "goes like snot". This black beast was my main go-to motor. I was disassembling it, removing the brushes to be replaced and such, and wouldn't you know it, the stupid yellow capacitor leg snapped off! (Or is it a resistor? Unfortunately I'm no electrician...)

Anyway, maybe one of you motor building gurus might even know what this resistor is (there's 2 of them on the positive side, and a blue 47 uF, 16V can capacitor on the negative side). The yellow ones look to be marked '102 C1K' on one side, and '733 AAA' on the other. Anyone know what that exact item is, or should I just go to the local electronics store and try to match it up with what's in stock? Or even better yet, want to sell me some?

I also need a complete endbell from one of those old Kyosho motors, or something that will work with one, if anybody has a bunch of old parts they don't need. Thanks in advance for any advice & assistance!

they are capacitors, usually around 0.1 uf, or something close. 102 tells me it's 1000pf, which seems low, but nonetheless........

they are easy to pick up at any electronic store or via mail, or etc. they are used to reduce radio noise due to the commutator arc'ing, and are typical used in this fashion:

one cap from + to the can
one cap from - to the can
one cap from + to -

they can all be the same values, 0.1uf.

Oh gawd, I hated those things! Remember trying to solder them all onto a stock chrome-can motor? And the big black one for the Novak ESCs on top of those three silly little ones? And then you STILL had glitching radios. Man, electronics have come a long way since 1988.



At least racers can't yell, "GLITCH!" anymore when they crash.

jwscab wrote:they are capacitors, usually around 0.1 uf, or something close. 102 tells me it's 1000pf, which seems low, but nonetheless........

they are easy to pick up at any electronic store or via mail, or etc. they are used to reduce radio noise due to the commutator arc'ing, and are typical used in this fashion:

one cap from + to the can
one cap from - to the can
one cap from + to -

they can all be the same values, 0.1uf.

Thanks both of you for the info! jwscab, I have indeed seen some motor setups with 3 blue capacitors all soldered on the same side of the motor, with a bigger can-shaped unit on the opposite side.

This particular motor only has the 2 yellow ones on one side, and a bigger blue can-shaped cap on the opposite side. When I rebuild this motor, should I just remove the broken yellow cap and replace with 1 of the same 0.1 uF unit?

Coelacanth wrote:When I rebuild this motor, should I just remove the broken yellow cap and replace with 1 of the same 0.1 uF unit?

Personally, I'd replace them all with three new .1 µF caps. If one was cracked, they probably all are, and you'll be chasing radio issues indefinitely.

Send yer Addy,I have some. JohnnySr

Actually, the broken one was broken by me, while trying to move it aside to check out the brushes. And strangely, glitchy radio issues were something I never had problems with on this car. My radio performance was flawless. I'll follow your suggestions, all the same.

I'd replace all three, and not worry about the other big one, it's not really needed.

Thanks again, gentlemen. Would anyone have a close-up picture of how the 3 would look when soldered? And I assume the orientation of the 3 capacitors themselves doesn't matter?

It was common for the (+) and (-) to ground would be soldered to the can on stock motors and to a tab from the endbell screw on mods. This would be done from one side of the endbell. You would then solder the (+) to (-) directly on the opposite side of the endbell tabs. I would usually solder the large black cap on that side as well.

I don't have any current photos of cap placement, because I don't put them on any of my shelfer or display motors.

I sent pics too