Loss of Y position on fast jogging.

[cncdrive]

Yes, I wanted to write step active low, sorry.

[AvB]

Hey this sounds like a good thing to check since it could be something that got altered when we switched to UCCNC.

Can you describe clearly what I'm looking for (on what screen) and how it should be set, so I can tell if it's in reverse?

[dezsoe]

The active low checkbox in the row of the step output.

stepal.png (6.05 KiB) Viewed 11405 times

[AvB]

Bummer - it looks fine. Not the problem.

[cncdrive]

it looks fine

How did you decide that it is fine? What was your method to determinate that it is fine? Please describe.

[Battwell]

try it as active high- instead of active low
ie change it and re test

[AvB]

Ah, OK, sorry - I thought you were indicating that if it was active low it was reversed. I will try.

[AvB]

I changed the step pin setting on all axes to active low (as shown in the first photo), saved the settings then ran a test again. After homing, all I did was jog manually in a diagonal direction about 400mm, then press Park 1 to return back to the park position which is close to the final Home position.

The second photo shows the result when I ran the Verify M925 macro. The Y axis was out of position by 4.4mm, and the X by 1.2. This is much worse, more than double the position loss that occurs when the step pins are not set active low. But even then it's a huge problem.

As mentioned earlier this never occurred with Mach3. And another interesting clue is that running the Park macro causes the biggest position loss. The Park move seems particularly fast and sudden (high accel and high velocity). But position loss does occur when manual jogging and to a lesser degree when running a toolpath.

[Battwell]

on general settings page. what is your kernal speed set to?

[cncdrive]

If it is worse then it is likely that the other way is the proper setting, but you could study your controller electronics to see if it inverts the step signal or not and how it is connected to your servo drives and then you could determinate if the setting should be active high or low.
Or if it worked fine with mach3 then you could check the setting there and make it the same in the UCCNC.

One more thing is that if it is an ethernet controller that you have then check the latency graph on the Profiles tab page.
The graph should never go to the maximum 20msec, if it does then there is a problem with your computer, it is not suitable to run the UCCNC or your ethernet card has a problem, drivers not installed properly or some IP confict if it is connected via router(s) or switch(es)...