Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Conrad Caron on July 13, 2018, 09:28:07 AM

Title: Z axis going deeper and deeper
Post by: Conrad Caron on July 13, 2018, 09:28:07 AM
Hi all i need help for my z axis .....when i do a project my z axis goes actually below my block and keeps going deeper and deeper.
Cheers
Title: Re: Z axis going deeper and deeper
Post by: joeaverage on July 13, 2018, 05:13:40 PM
Hi,
it sounds like the Z axis is 'losing steps'. I know it sounds weird, how could it lose a step and yet go still lower, that sounds
like gaining a step doesn't it? In fact either gaining or losing a step or steps have the same effect, depending on how your Z axis is arranged
it might mean it goes higher OR lower.


Try running the program but with the Z axis above the part, 'cutting air', without the spindle running. Does it behave? Now run it again with the
spindle running. Does it behave? Spindles often produce a lot of electrical noise and can affect things like losing steps.

Its also possible that you have the Z axis tuned to agressively and the stepper can't keep up. Try a low maximum velocity in the Z axis tuning page with
an even lower acceleration. If it helps then you know you'll have to work out the reliable limits of your Z axis.

Craig
Title: Re: Z axis going deeper and deeper
Post by: rmarotz on July 29, 2018, 07:29:59 PM
Good afternoon all, I am also experiencing this issue.  I did watch the YouTube video on Finding Lost Steps which was very helpful.  I disabled my x an y axis and ran the troublesome program twice with just the z axis in motion (cutting air) and had no missed steps.  As soon as I try to cut material I start losing steps again.  I am now going to re-run the test but with my spindle on to see if I have a noise issue. Anyone have other suggestions? 

Thank you for assistance.

Russell
Title: Re: Z axis going deeper and deeper
Post by: AFigula on July 30, 2018, 12:43:55 PM
Hi all, I had the same problem years back Z ramping up...cutting air. I found it happened during very warm days, this may sound weird but I fixed the ramping up by putting a fan directly blowing on my G540 "Go Figure".


Al 
Title: Re: Z axis going deeper and deeper
Post by: garyhlucas on July 30, 2018, 01:39:13 PM
The Z can be a problem because of the spindle weight and the fact that tools tend to pull down so the Z motor can’t lift the weight. A counterbalance gas spring may be needed.