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Author Topic: Steps per unit output will not change axis Movement  (Read 126 times)

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Steps per unit output will not change axis Movement
« on: May 23, 2020, 01:14:49 AM »
I am setting up my 1st 3 axis RF45 clone mill and using the following, PMDX126, PMSX107. Warp9ESS, Gecko 320, US digital E2 encoders.
I am able to jog the axis and move them but the movements requested does not match the output. I have tried manipulating the per unit calculations in the Motors tab of Mach4 but no matter the data i Input the movement stays the same on the axis or relatively close. For example request 1 unit movement using 1" indication at 6400 counts i get .1 using the wizard if tells me to try some larger number like 32000 I will input the data in the motor set up save and then go back to try it and the distance remains the same at .1 inch. I have never ran into this issue on my other plasma tables or router but they are all stepper motors and this is a servo set up. I am not sure what to do next spent way to much time on this issue. The attached schematic is how i have it wired with the exception of having a 5v power supply to the G320's i have utilized the 126 board as well for the control voltage to them to see if it changes anything.
Re: Steps per unit output will not change axis Movement
« Reply #1 on: May 23, 2020, 05:36:50 AM »
Hi,
it sounds to me that you don't have the servo/encoder/drive loop working correctly.

Do you have some means of testing the step/direction response other than using Mach and your BOB?

For instance do you have a siganl generator that would allow you to pulse the step input of each drive?

Craig
My wife left with my best friend...
     and I miss him!
Re: Steps per unit output will not change axis Movement
« Reply #2 on: May 23, 2020, 10:58:45 AM »
They all tested fine when I had a friend of mine put them on his scope and tune them to the gecko drive so I know they work at something on my end I can’t figure out Now that I have them all wired into the cabinet then on the machine. The only thing I found odd from the print I attached is when I wired the comment to the PC ground like the print Is drawn I get zero movement out of the drives. But they all seem to function when The alternative 5 V power supply is hooked up to them instead. And when connected to the +5 on the Bob they jog fine to just not When the common is connected to thePC ground.
Re: Steps per unit output will not change axis Movement
« Reply #3 on: May 29, 2020, 08:39:00 AM »
I had that issue. NO matter what I put in the steps/in no change in movement. After power cycle the setting took. Several times the Mach steps calculator wasn't even close to being right, other times it was right on. When I got close I just used my own calculator. I used the Mach calculator when I was within a few tho and it recommended over 20000 step change!

Offline Graham Waterworth

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Re: Steps per unit output will not change axis Movement
« Reply #4 on: May 29, 2020, 08:45:57 AM »
When using servo motors the steps per is based on the encoder pulses so a 1024 per rev encoder would be 4096 steps divided by your pitch and drive ratio.

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Re: Steps per unit output will not change axis Movement
« Reply #5 on: May 29, 2020, 10:32:04 AM »
After a lengthy process of verifying every connection and removing all the pin style connections at the box and direct wiring to the board it started to work as it should. Wish I new the exact wire connection that was causing the problem but it’s working and we’re moving forward to true up all the axis’s and making some parts.