# Thread: 4th Axis Motor Setup Parameters

1. ## 4th Axis Motor Setup Parameters

Hi,

I have a question on the motor parameter setting for a 4th axis (rotary table). What is the unit of measure for calculating the number of steps per unit of measure? Is it 1 degree as a unit for a 4th axis?

I understand the calculation for a ball-screw:
200 step motor * 10ustep of drive * 5 threads per inch = steps per unit of measure (inch in this example) = 10000 steps.

Would the rotary drive setting be:
200 step motor * 10ustep of drive * 1 degree rotation = steps per unit of measure (degree in this example) = 2000 steps.

Thanks,
Robert

2. Is your 4th axis direct drive, or is there a gear or belt reduction?

Step/unit is per degree, but you need the gearing to calculate that, unless it's direct drive, which would be 200*10/360.

3. Thanks Gerry....

Yes, it has a gear reduction. I though about posting that but figured it would have just confused the issue.

Thanks for the info as the per degree was the part I was not sure about.

Robert

03-13-2012, 10:02 AM