So last week I wrote about starting to learn electronics. I was having some difficulty understanding what was going wrong with my circuit. This week i got some probes for my oscilloscope, and that at least helped me see that indeed when the servo turned the best, the control signal looked most like a square wave. it didn't tell me why I wasn't getting that i nthe way I expected. but it is still cool to have the scope up and running.
The other thing I did was buy an arduino uno. This is kind of cheating. It makes everything much much easier. Part of that is being on a well trodden path. There are lots of people using arduino's for lots of projects. and controlling a servo even has example code built right into the arduino ide. It was so absurdly simple to get a servo scanning back and forth that it does feel a little like cheating.
Today I moved on from servo, to stepper motor. I already had a sparkfun stepper driver (4.2) and I found a really helpful website that had a sample wiring and sample program to get things going.
Basically the boards mean I don't have to worry too much about things at a resistor/capacitor level, andjust make sure I wire up the right stuff to the right pins of the boards, then worry about the code.
Even that might turn out to be , if anything, too easy. There is already an opensource project for interpreting G-Code on an arduino uno. What does that mean? It means with a couple more stepper motors, and some setup and I can have a 3 axis cnc electronics all ready to go. Just waiting for me to wire it to something.
Some time ago I built what I hopped would be the 3 axis physical cnc part. I have some concern that it may be altogether too heavy and too poorly made to get good results from. but I figure I should at least attempt to couple my stepper to the main axis and see if I can drive it. If not then I'll just build something smaller/ligher/better designed. but if I can push enough torque to move the main caridge, then the other axis' should be much easier.
I just need to figure out how to couple the shaft of the stepper to the threaded rod in a way that is secure and doesn't have much/any play in it. Also I think I probably need to move a few things on the original cnc to make everything run smoothly without pushing/pulling the frame apart.
Anyway, here is my not very neat setup for running a single stepper motor:
oh, and here is the oscilloscope!