Need Help figuring out how to setup PP for stepper

I have a 3axis Chinese CNC 6090B with RichAuto A11 DSP and DMA860H drives. I finally am getting around to using the 4th axis, which works off of a switch that converts x axis in to rotary.

The issue I am running in to is that the stepping ratio seems to be off. A 19.05mm diameter rod has a travel of 59.8473mm. But when I do that on my 4th axis, it almost goes around two full revolution instead of one. Doing further testing it appears the maximum travel I am getting off of my 4th axis motor is 30mm. The X axis is designed to move 0.5 for each pulse so that equates to about 60 pulses to do the full 360 deg, hence it appear the 4th axis stepper motor is doing 6 deg per pulse turn. This tells me stepper motors for the X axis and the 4th axis were not selected properly by the manufacturer. I have tried to contact the local rep and their suggestion is to upgrade to the RichAuto B18 4axis solution, which is not cheap! I wondering if there is a way to setup a post processor (pp) file to accommodate this difference between stepper motors so that I can get proper results on any of the wrap jobs I am trying to create in Aspire? Or are there any recommendations for a 4th axis 4 wire stepper motor setup that can work with the DMA860H drive that is set to Ref current: 4.86A, PK current: 5.83A, @ half current, and 1600 pulses?

Thank you in advance.

Sincerely,
AF

The setup for pulses to movement is within the DSP hand control. If as you describe there seems to be a difference of 2:1, you will have to reconfigure the DSP to provide the correct number of pulses for correct movement when using the X axis to control the A (C) rotary axis.

If you go to the B18, the configuration for the axes will be for all 4 axis. A better solution but as you mention, higher cost. Look at the time/effort of having something that just works versus having to fluff around changing it each time you switch between X and A and back again.

One possible "solution" might be to edit the code for rotary use by halving the "distance" values for X when used for A but again, cumbersome and prone to human error.

Thanx for the thoughts. I did try changing the DSP but I noticed a reboot is needed which would throw off the x axis. I guess I need to seriously consider the B18 upgrade since I agree with you that it could be cumbersome to have to remember to calculate and update the pp for various sizes each time.