View Full Version : Cheap Speed Controllers
05-05-2008, 09:19 PM
I am doing a personal project that needs more powerful motors than can be driven right from my processor circuit. I guess I need a speed controller. For this project, accuracy is VERY important, but not $150 each important.. I need (a minimum) of 2 motors to be driven for under $100 (if possible.) I have heard of speed controllers with the ability to control multiple motors. Any suggestions?
05-05-2008, 09:26 PM
Have any voltage/current requirements? Will the motors always be in free-spin or will they have a load? Will it be a static or dynamic (aka changing) load?
05-05-2008, 09:36 PM
How much current do these motors draw? We got some Banebots controllers for $30 each, they are reversible, have a BEC that works to power a Vex signal splitter, and are very small. Low current....they are designed to power a motor at only 3 amps continuously, but they seem to work ok in the underwater robot the students built for the NURC.
Be very careful to get controllers that will go both ways with a single PWM input, if you need that capability...I messed up first time and ordered some that did not!
05-05-2008, 09:39 PM
RobotMarketplace has a lot of speed controllers available.
How much current is needed? what motors?
I think you'll find them to be rather expensive (Victors are $150!).
05-05-2008, 10:29 PM
To answer everyone's question, I don't know how much voltage I will have. I mean, processors usually require 5v to operate, so my board will probably have 5v already.. weather I power it from a Li-ion or a few AAs, i could transform it into anything i want.
The motors will probably need around 100oz-in of torque, but thats just a guess.. I am still in my early design phase..
The BB one looks pretty nice, and I like the size!
I am not used to ordering from this industry, so I don't know the trusted suppliers (aside from digikey and mcmaster).. I usually end up breaking down and asking the guy at Radio Shack what to do :( I looked on the robot-marketplace website, and found most motors to be overpowered.. I think that one of these will do:
On the plus side, it looks like they can all be driven with 5V.. So I can drive it directly from my processor circuit. My robot isn't going to be more than 3-5lbs, so 2-4 of these should be plenty..
I will continue my search for motors and speed controllers, but thanks for the suggestion.
05-06-2008, 12:35 PM
If you are using RC PWM to control the speeds, you can look into hobby type motor controllers. These controlers are light weight, small, and high current. They vary from 25A to 90A
with a simple 25A the costs are as low as 30 dollars, and with 60amps average are about 80 dollars. These are small controllers that are used for electric airplanes. You will find that these ESC's are light weight and very small but highly efficient.
Though if you want it to be bi directional, then you will have to find an esc for cars, and not planes.
I get my sources from www.amainhobbies.com
Heres the link esc for cars: click the Electronic speed controller icon.
And heres the link to the escs for planes/helicopters:
05-12-2008, 01:47 PM
05-12-2008, 01:59 PM
I actually just purchased some HB-25 motor controllers, when I get it, i'll post how they work out.
Heres a link:
edit: they may actually be more powerful than you need
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