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Author Topic: Steps per unit output will not change axis Movement  (Read 838 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
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
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!

Online 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.

Without engineers the world stops
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.