This is my first post, so easy on me if I missed something about etiquet. I am a senior in electrical engineering and my senior design project is due on Tuesday of next week. My project was to build a CNC mill. Soup to nuts... (start to finish). I have systems working independantly, but I am having major issues when I start hooking things up together. Here are my problems and data.
I am using a NEMA23 Motor from Anahiem Automation listed below.
It isn't listed on the sheet, but the tech guy said 3.3V at 2A in Unipolar mode which is what I am running.
In order to get them to pull even close to 2A I am running them at 9V and everything seems to be working. EXCEPT!!! They will only spin at about 37.5rmp. This is WAY WAY to slow when using a polling controller like the one I am using, and I am having trouble with the controller missing pulses because of how long it takes to execute a step. I tried speeding it up, and the motor just jerks around like it isn't switching right, which means one of two things:
1. The motor can't spin that fast
2. My switching Mosfets aren't opening and closing fully
But, my FETs say they have rise and fall times in the nS range, so I doubt that is the case. But I just can't believe that this motor will only spin at 40rpm, am I missing something here?
As for the controller, we originally used BS2 (basicstamp 2) for each axis independantly, but, later found out that they would only run at about 4000 instructions per second, which means, after you slow that down for motor stepping, you are back to polling at the speed of smell again. So we switched to the Motorola 68HC12 and haven't gotten it done enough to test it yet, but still don't know how we are getting ahead if we can only step at 40rpm...
Somebody please give me some heads up here on what I could possible be doing wrong?
I have schematics and code and diagrams for everything if it would help...