We’ve done the simplest thing I think is possible. We used the 5" wheels but removed the tread from them so that we have much better turning with our 4 wheel drive system. Prior to removing them, the 4" with the tread caused so much friction when trying to turn on carpet that we broke the clutch (since they don’t work properly and break at the max torque instead of slipping). Of course having an 11 lb. robot for those motors probably isn’t too nice when you only have 1 motor on each side driving.
If you use the default program that comes with the VEX (in other words, don’t do any EasyC programming), you can control two motors and a servo with the RC transmitter. I just left the transmitter in the default Tank 2 mode and hooked a servo up to motor port 4. After that, I was able to use tank mode to control the two motors in the standard SquareBot setup and I was able to use Channel 3 (on the left) to control the servo. On channel 3, up and down controls the left motor while side to side controls the servo. I’m using the servo to pan a wireless vidoe camera from side to side. It’s cool!
One bummer though: when I try to use EasyC to do any programming that includes RC control, this capability goes away. So, I just redownload the default program to get it to work again. If anyone knows how to retain the side to side servo control even when using EasyC 1.1, I’d love to hear about it. Thanks.
All that is happening in the default code is probably a direct write from the value of a channel to the value of the pwm with the same number. The left to right on the left joystick is actually channel 4 (channel 3 is only the up and down), so it is likely the value of the channel 4 joystick is being directly fed to pwm 4, which controls the servo.
There is a function in EasyC that directly writes a channel to a pwm, but I do not remember it off of the top of my head (EasyC is installed on my laptop, not my desktop). I think it is something like RxControl();
Look for Erector set components that might work with VEX, since both are made of metal and use siilar building construction methods.
Consider using the rubber tread on LEGO parts an covering the VEX wheels, giving them more grip.
It does work, i bought about 5 feet for a few bucks at a local hardware store, however it is a tighter fit then you really want, I think the shafts that come with vex are a few thousands smaller, or the edges are more rounded ect.
I thought that I have an Erector Set but I couldn’t find it. The Erector Sets are made by different companies. I think that the older Erector Sets are better than newer Erector Sets. The screws and nuts in newer Erector Sets are junk.