Linux CNC - Mesa Card 7i96s with iHSV57-XX Servo Motor

I am not sure that I would trust a DTI over 20mm more than I would trust a ballscrew.
In my opinion the step scale should be based on the calculated leadscrew pitch and the gear ratios.

andypugh wrote:

I am not sure that I would trust a DTI over 20mm more than I would trust a ballscrew.
In my opinion the step scale should be based on the calculated leadscrew pitch and the gear ratios.
 

Alright well in this guys particular case I don't think he's far off enough to have miscalculated and from his 2 movements he is coming up short 0.01mm/mm..........so what should he do?

0.01 over 20mm with a loss of 5 steps per 2.5mm out of 4000 steps..took a while but getting the hang of it. Backlash close to gone.

Just wanted to say thank you.

I think I can remove the 0.01 as well.

I'm not sure if you are on the right page. There should not be ANY lost steps. Lost steps only ocurr if a motor gets hot or you ask too much of it. Genrally Acceleration too high.

Listen to Andy.
Whit is your ball screw pitch (say its 5mm)
Is there any gearbox/belt reduction (say its 3:1)
What is your steps per rev (say its 200)
What is your microstepping. (say its 10 x) 

So for our example above, the motor needs  to turn 3 revs to travel 5mm.
Thats 3 x 200 x 10 steps per 5 mm = 6000
Your steps per mm = 6000/5 = 1200

 

The servos are able to indicate missed micro steps. Its related to how the motor is setup. So it could indicate one of the 6000 items in the above example was missed. Its a small error.

Its explained well here,

Thank you for the reply.

I'm not familiar with those servos but as stated before, you shouldn't be "missing" any steps. Doesn't matter if you're using a stepper motor or servo commanded through step and direction. There could be some misconfiguration between the SD command and feedback.

Either way "missed steps" are not acceptable and you can't tune your way out of it. When I suggested you adjust the STEP_SCALE, I was talking about like 1 or 2 increments beyond what is calculated as ball/lead screws are not perfect but it's becoming clear that if you still have some issue or had to make major adjustments, then something is wrong with your setup