Is it right that you could mount an Encoder to the rear shaft of a Dual Shaft Nema? Does that mean you would then have step feedback to the program? If so, is it straight forward? Or have I got it completely wrong? Which wouldn't be unusual. Gray
Hi Gray, I am sure you could do that but I am not sure it would serve a useful purpose for a stepper motor (servo's are an entirely different matter though). Stepper motors, assuming a properly constructed machine, do not loose or gain steps - they only move the commanded amount so the driving software always knows the exact position of each motor. Tweakie.
Nice one my friend. Their not 'sound dampers', they are 'mid-band resonance dampeners' - look real cool. Tweakie.
Well I'll go to the foot of our stairs. Silly me. Of course they are. Well, I know what I meant. Do they actually do anything significant? I could always stick a flag or something on the Z axis. Gray
I know you knew - just pulling your leg. Perhaps best to just stick a flag on it - I think most of the leading stepper driver chips nowadays incorporate pulse-shift to counteract and suppress the resonance when it is detected. I think Gecko were the first to incorporate these chips in their products but others were quick to follow. Tweakie.
Now I didn't know that!! Does it work, make it a bit quieter? I didn't realise the answer would lie in the Driver. Well well. Gray
I hate to be contrary with Tweakie but the dual shaft stepper motors are specifically designed to mount an encoder on the back side for closed loop feedback. In some applications like flight control systems the steppers are preferred to the servos because they actively maintain position vs synchros which require a dampening system and braking system.
Good point Brian and I am pleased you made it. I am sure that there are many out there who do use closed loop stepper motor systems with their CNC machines and are extremely pleased with the result but I do wonder if it is really necessary. For me open loop rules. Tweakie.
Hey Tweakie I agree...for CNC apps I think open loop is preferable in a lot of (if not most) cases. I was thinking more along the lines of other uses for steppers like in aviation or process control systems where they may be used because of their active position holding capability.
