O/T: make an RC car motor slower

[myothercarsa2cv]

Odd request, but you guys know everything! What's the best way to make an RC car motor slooooooow? I am working on a fun project: making an exorcist kid mannequin. I've butchered the RC car, got all the bits, and am almost ready to mount the motor in the body, but one thing I didn't factor in was just how fast these motors spin! Any ideas? The freer the better ;) I tried a resistor from the LED circuit (red red black gold, 22ohm?) in line with the motor and there was no movement... Could diodes be the answer?

[Jonathan Kay]

Thought it was going to be about slowing a competitor's!

Chopper circuit, possibly using thyristors? (Is there a much more modern way of doing the same thing?)

Jonathan

[Dr Slotter]

Might be easier to buy a stepper motor.

[Bricol]

Brushed or brushless?

Lower voltage is the easiest, assuming brushed.  Power output will drop of course.  Otherwise, smaller motor, or gearbox.

[andy_h]

Why make it complicated.... use a gear to gear the speed down :)

 

 

[myothercarsa2cv]

Cheers guys. Basically have zero budget for this build so a £5 RC car was bought! I assume it's brushed? Looks like a Scalectrix motor. Will look into those options, tried dropping down to two AAAs instead of 5 AAs, this has made a difference, tried 1 AAA and that didn't work at all. I wonder if there's a minimum voltage to prevent complete discharge of batteries? 

[sjmmarsh]

2cv

you need one of these (or similar) from an old rc car. They never use them now because the electronic controllers are so much better and reliable. 

I may have one I took off an old car when I upgraded it. I'll have a look when I next go to my lockup. 

Steve

http://www.tamiyaclub.com/pictureframe.asp?t=n&id=img16134_2A1TG_1.jpg

I think the 200 ohm resistor is too big. The variable resistors are basically just wound wire. 

 

[myothercarsa2cv]

Thanks Steve! How does it wire in? Does it just sit between the PCB and the motor?

[jackb_ms]

The speed of a DC motor varies with the voltage supplied to the motor.

I would used a battery with a lower voltage or use a voltage regulator.

I have one f the speed regulator from a vry old Monster Beetle if you want .

Jack

[myothercarsa2cv]

Hi Jack,

Thanks! I've already reduced the number of batteries down from 5 to 2, going to down to one and nothing works. Not sure why! That's very kind, and would be very useful! I'll drop you a PM and I'll see if I can get it working that way!

cheers,

John

[Golf Juliet Tango]

Why make it complicated.... use a gear to gear the speed down :)

My thought exactly

[myothercarsa2cv]

Well Jack found me a 1000:1 geared motor for a fiver, which looks like it will do the trick! Let's see...!

Thanks all for the input, been an education and the POBC is always a marvel!