Rotary With 1000 Pulse/Rev And Acron

[porcupinehorseracing]

Hello again,

I purchased and wired everything. I'm extremely happy with Acorn and the documentation available.

How do I calculate the Overall Turns Ratio? The rotary table has a 50:1 gear ratio and I had assumed I'd take 360 degrees and divide that by 50 for a 7.2 ratio. However, this results in the table rotating short of 360 degrees. Tormach uses 1000 steps/revolution while I have changed the driver and CNC12 to 1600.

With Tormach's setup - 360/50/1000 = .0072 angular degrees per step
With a custom setup - 360/50/1600 = .0045 angular degrees per step (Theoretically. I'm sure there is backlash)

I called Tormach's support but he was unsure of how many steps per revolution on the motor. The case is riveted together and I'd rather not try to open it.

I cobbled up a dial indicator setup and an Overall Turns Ratio of ~7.05 seems to be getting close. What should my calculation be?

I've pulled up Marty's Overall Turn Ratio spreadsheet but I dont think it's intended for rotary travel.

I'm using the DB25 output. The software is assigning the rotary to Axis 1 and X. Is there a way to assign the rotary to Axis 4 or to A?

Thank you for your help.

[cnckeith]

verify that the motor (sitting on the bench) turns one revoltion when commanded to move 1600 steps.

do this by bench testing the motor as a linear axis with a Overall Turns ratio set to 1

then command a 1" move (G1W1F50) the motor should turn 1 revolution if you have the steps per rev set the same on both the driver and Acorn Wizard.

once confirmed then you can bolt the motor up the rotary table change to rotary axis in the Wizard and set the mechanical gear ratio for the rotary table using the units "degrees per revolution" said another way, how many degrees does the rotary table move if you rotate the axis motor shaft one revolution?

[porcupinehorseracing]

Hi Keith,

I appreciate the response but I am unable to get to the motor itself as the case is riveted together. The other option would be taking the harmonic drive out from the front, however, Tormach has said that I'd have to repack the grease for the bearings and I'd rather not get into that.

Thanks.

[cnckeith]

Hi Keith,

I appreciate the response but I am unable to get to the motor itself as the case is riveted together. The other option would be taking the harmonic drive out from the front, however, Tormach has said that I'd have to repack the grease for the bearings and I'd rather not get into that.

Thanks.

ok well you can forgo the step per rev test and hope that you have the drive and the Wizard set the same and working

and go straight to setting the axis as rotary and then setting the rotary revs per degree . then command a 360 degree rotary move and see if it turns one rev. easy peasy.