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Author Topic: Homing help  (Read 6003 times)

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Re: Homing help
« Reply #20 on: December 16, 2011, 10:35:07 AM »
Ok imperial is just fine if it is easier
Mirco steps are set to 1/8
again thats only because its the way it was shown in the instructions
Re: Homing help
« Reply #21 on: December 16, 2011, 10:58:17 AM »
Found this on the zentool site
I will try this tonight

Please use 32512 steps/unit for all three axis if you are using inch unit. The driver is set to 1/8 micro step by default(you can change it). So 25.4(mm/inch) / 1.25 (leadscrew pitch) * 200 (full steps per revolution) * 8 (microstep) = 32512 steps/unit.

Re: Homing help
« Reply #22 on: December 17, 2011, 12:35:09 AM »
ya still not working correctly

Offline Hood

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Re: Homing help
« Reply #23 on: December 17, 2011, 04:28:17 AM »
That should be the correct steps per unit if you have kept the drives at 1/8 stepping, did you also remember to fist change your native units to Inch from the Config menu then Set Native Units?
What is the actual problem now?
If you go to the MDI screen and zero the X DRO then command a G0X1 from the MDI line does it travel 1 inch?
Hood
Re: Homing help
« Reply #24 on: December 20, 2011, 12:20:32 AM »
Sorry Hood, It works perfect now, it was my learning how to zero the work on the table that needed work
got it now
My digital calipers show exactly 1 inch which I think is amazing
any tips on motor tuning?
Tim

Offline Hood

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Re: Homing help
« Reply #25 on: December 20, 2011, 03:19:25 AM »
Steppers are in a way the easiest to set up as you dont have to do any real tuning between the motor and drive like you have to do with a servo. They are however a bit more problematic setting in Mach as you do not have any idea what the max velocity will be where with a servo you do.
Its been a long time since I used steppers but the way I used to do things was have the accel at a low value and keep increasing the velocity and testing until the  motor started stalling. I then dropped that by 50% and then increased the accel in steps until the motor again started stalling. From there I knew the max of each individual component and could workout a happy medium but again it was trial and error even to find the sweet spot.
One thing I will say however is to my mind it is much better to have a fast acceleration with a slower Velocity than the other way about, that is why I love servos as you can have both but steppers you have to trade one against the other.
Hood