Driver recomendations

[pminmo]

No R5 on the DS version shouldn't be there, the SS version is correct. It was intended to be a pullup for the Dir signal, but was drawn on the wrong side of the 10K series resistor. It should have pulled up pin 3 of JP1. I just eliminated it on the ss version, and don't install it on the double sided version. Printer ports vary, but usually have an active high side drive. My thought process was a fall back postition if I needed to have a termination.

Phil

[sp00k1e]

Pminmo.
I found the problem after I got the scope. Running Mach2 the minimum step pulse width was too small, looking at pin 5 of ic1 the filter of R17 and C14 was causing a very small triangular wave which wasnt allowing the input to the inverter to be enough to operate. Is there a reason to have such a large RC time as this must limit the max step rate available ( not in my case as 5uS pulse width is fine). I put a 330R in parallel with the 10k and managed to get the motor whistling at 1uS pulse width.
On a side note what is the best setting to have the microstepping? on full step the motor whistles although on less torque, im testing with a loose motor on the bench, on 1/8th step the motor top speed is significantly slower, I assumed that since Mach2 operates at such a speed the max motor speed wouldnt change or maybe increase and the torque would increase.
anyway thanks for the circuits, this forum is great, plans for everything, JGro and you deserve a medal !

Paul

[pminmo]

The RC constant on the step input is not considered long vs a stepper motor. The reason to keep it longer is improved noise immunity. Most stepper motors really drop off torque wise above 1khz at full step, so even if you are screeming along at 16K pulse rate with 1/8th microstep, thats only 62.5us pulse rep rate and a 20us pulse flys through the filter.
Sounds like your board is running? Can you post a picture? Please, Please nobody has posted a completed picture of the ss board, make my day. :-)

Thanks for the medal. :-) The old saying "giving is better than receiving" is so true, I do enjoy helping! Big kudo's to ynneb (Benny) though, he through out the line, and I swallowed hook, line, sinker and all.

Phil

On the microstep question, depends on what you wind up with as a problem torque vs resonance. Microstepping reduces the resonance problem but lowers the torque.

[sp00k1e]

I was just about to go to bed but here it is!
Please understand that i am just getting this running and it wont be this untidy in the end, and I have just removed the previous circuits from my box, .
Regarding the microstepping, I connected the machine up and discovered that the top speed doesnt seem to change when under load irrespective of the microstepping rate but the smoothness does and presumably the accuracy.

Paul

[pminmo]

Paul,
Thanks, great work. Untidy means your doing something.

Phil