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From steps/s to mm/s speed conversion
Posted: Sat Feb 05, 2022 10:24 pm
by Loni
Hello everyone
I am working with a phidget controller model 1067, together with a stepper motor that has a step angle of 1.8 degrees. The motor doesn't have a gearbox. It is attached to a ball screw.
When the motor does 1 rotation, the distance performed by the block attached is 3.6mm.
Could you please provide a bit of support on how to translate the speed units shown in the program as 100 steps/s to mm/s units?
I thank you for your time and hope for your understanding.
Kind Regards
Re: From steps/s to mm/s speed conversion
Posted: Mon Feb 07, 2022 9:26 am
by mparadis
"Position" in our libraries is measured in microsteps, which are 1/16th of a step. You can figure out the conversion with unit analysis:
Code: Select all
1 step 16 microstep 360°
______ x ____________ x ________ = 3200 microsteps/rotation
1.8° 1 step 1 rotation
Then, if your ball screw moves 3.6mm per rotation,
Code: Select all
3200 microsteps 1 rotation
_______________ x _____________ = 888.889 microsteps/mm
rotation 3.6mm
So if you set your target position to 889, the ball screw should move 1mm.
If your "3.6mm" number was determined experimentally, you may want to use the actual gear ratio of the ball screw to get a more accurate conversion.
Re: From steps/s to mm/s speed conversion
Posted: Tue Feb 08, 2022 5:31 pm
by Loni
Hello mparadis
Many thanks for your reply.
Actually, I have a DBX1204-100 type linear actuator, and a stepper motor model 42BYGH48. I have checked the linear actuator, but I can't find the actual gear ratio of the ball screw.
Perhaps from your experience, do you know what would be the most typical gear ratio for this type of actuator.
Many thanks
Re: From steps/s to mm/s speed conversion
Posted: Wed Feb 09, 2022 10:04 am
by mparadis
Sorry, I don't know what the gear ratio would be.
Another way you can improve the accuracy of your conversion is by measuring the distance of the actuator at multiple positions. So if you record the distance at position 1000, 2000, 3000, etc.. and plot a bunch of points on a graph in excel or google sheets, you can take the line of best fit and then use the equation of that line to convert any position value to a displacement.
Re: From steps/s to mm/s speed conversion
Posted: Wed Feb 09, 2022 4:21 pm
by Loni
Thank you for your reply.
I might need to open the old recipes and see if I can contact the manufacturer of it.
Have a nice day.