Setting machine coords to zero - without limt switches

[crjohnson]

Hi all,

I am starting to get my new machine build running, it does not currently have limit switches yet, they are being worked on but will take a little while.

So in the mean time I am trying to set up some safe soft limits to prevent me over-travelling the machine. I am having trouble zeroing the macien coordinates though.

I saw another post where the fix was to home-all, then zero-all, but this does not re-zero my machine coordinates for some reason.

I have tried with and without softlimits enabled, but I guess I am missing something when it comes to running this software. Any help would be appreciated!

My machine runs an AXBB-e and UCCNC, firmware 1.0000, software 1.2113.

[dezsoe]

Write 0 in "write offset on homing" and check "auto set". If home pin and port are 0 then homing the axis will zero the machine coordinate.

[crjohnson]

Thanks dezsoe, the 'write offset on homing' was already 0 on all axis and I'm 99% certain I tried having the auto-set checked and unchecked, but will try again.

Home pin and port are all set to zero too, 'active-low' is unchecked and the Z axis has the dir-positive checked.

Lastly, I have axis A set as a slave to Y as I am running 2 steppers, if that makes any difference?

Cheers

[dezsoe]

Use the same settings for A. Don't forget to apply or save settings.

[crjohnson]

Well that all seems to work now, thanks dezsoe!

Another thing thats been bothering me (not really a uccnc thing), is my y-axis steppers seem to have a harsh vibration or resonance at (what I thought was) low rpm's.

They are nema23, omc stepper online brand, 339oz.in, 4amp (link below), driven by 5.6amp, DM556T drivers and dedicated 48V power supply. Initially when I ran these below 2600mm/min (5mm pitch ballscrews), they ran nice and smooth. But now it seems like the resonance is happening at lower mm/min speeds. I tried running these at 1000steps/rev and also 2000, no difference and I started with 100kHz kernal freq, tried 200kHz, no difference. They wouldnt actually do anything when setting UCCNC to 200kHz kernal freq, though my Z axis would still operate.

Does anyone know what might be causing this vibration?

They are wired up exactly the same as my X and Z axis, they have no issues and run very smooth. I thought I might be spinning them too fast, but even at lower speeds it is happening. Also these are running without the ballscrews connected, so no load. If I try to put some load on by holding the coupling with my hand, they still seems to vibrate.




Stepper motor: https://www.omc-stepperonline.com/nema- ... &limit=100

Driver: https://www.omc-stepperonline.com/digit ... m556t.html

[DavidR8]

I had some weird resonance on my X and it turned out to be a bad connection on one of the four stepper wires.