Main > Everything Else
RC Engine Speed controller
csa3d:
Hey all,
So I'm messing around with a 5v RC Motor to drive my rotating monitor rig. My first attempts were swiveling poorly, and left me wanting a serious torqued engine and a super slick lazy susan settup. Well, I've created such. Now I'm finding that my monitor goes from 0-90 in 1.5 seconds! While that might sound good, it's not. I would like to decrease the time to about 5 seconds, or something much gentler then achieved.
Can I put an electronic equivalent of a "dimmer switch" between the motor leads to drop the voltage to make it spin slower... or is this bad and are there better/safer ways to do this. I don't want to burn the house down after all.
Thanks in advance.
-csa
csa3d:
Searching more, I'm considering limiting the speed of my rotating monitor motor with a setup like so and a 5K-Ohm Linear Taper Potentiometer like this one. Thoughts? :dunno
-csa
danny_galaga:
short answer: no.
electric motors like those used in rc vehicles develop very little torque when using a resistor to reduce the speed. you really need to look at gearing it so that it can run at peak revs. however, having said that, you could look at making an electronic speed controller. or modifying an RC one so you dont have to use a radio. they control speed buy 'chopping' up the power. basically it is switching full on, then full off at various frequencies. the net result is that you have full torque, even at low speeds.
which is actually something like the dimmer switch you talked of. thats how they work. they work on a much higher voltage of course, but same principle...
protokatie:
Gearing > pulsing IMHO. If you can get (or make) the gear box with the correct ratios, it would be a much smoother and possibly longer lasting solution to pulsing (I may be wrong on that last point).
As per what I think I got from your question: If you undervolt an electric motor, it can increase the risk of shorting it out. This may sound counter intuitive, but an electric motor that is undervolted under load can heat up quite a bit as an electric motor is not much more than a longish short circuit. If it isn't turning at a decent rate, or if it is held in a stop position for enough time, the coils will just simply get hot. For a small RC motor, it doesnt take much heat to melt the very thin plastic coating around the wires in the coil, or even heat the very very thin wire in the coil to the point of breaking it (thus killing the motor).
danny_galaga:
very true with the under-volting thing. this is how starter motors get burnt out. when the battery is half dead...
in this case though, csa3d is proposing to use a resistor to slow the motor down. voltage will be the same, but current will be limited. due to lack of torque, it just wont do much of anything!
Navigation
[0] Message Index
[#] Next page
Go to full version