stepper motor missing steps?

Hi,
not really such a new topic and I put the question mark in the subject because I may be wrong about missing steps.
Here is my problem....
I cut a 90mm dia pocket in 10mm thick aluminium 1mm steps 60% stepover (hope my terminology is correct)

I appear to have missed steps in the -x axis on each pass so that I ended up with the -x axis side showin a 'staircase effect' and the + x axis being shifted to the right.

This caused a little over a 1mm shift in the pocket and the profile cut was therefore moved as well, the whole job is a mess.

The job is not important but getting the machine correct is.

Then using the stepconf wizard, I tested the x axis (actually tested all) I had set a velocity of 10mm/s and 100mm/s2 acceleration. I changed the acceleration to 70mm/s2 and retested with a +- 100mm range and put a lot of pressure on the axis in each direction ( lot of body weight) and repeated this several times and it return to the start point precisely.
I did the same with the y axis.

Edit: (I may not have done this enough times as the cutting total was 16 circles for each 1mm depth of cut = 160 circles)

None of that helped, so I replaced my switchmode PSU with a pretty heavy duty linear one (which I had been meaning to do for a while), tried again, same result exactly

I went through the latency test and fine tuned it, test again, same result

I am now asking for help as I have not only run out of ideas I have also run out of material, I have wasted a lot of aluminium and time on this and I still am getting identical poor results.

Is there anything else I can look at? is it possible that the old P4 PC could be causing the issue (I don't think so as it is too consistent in the - x direction)

I have attached a couple of photo's to show the steps on the left (-x axis) and the extent of them with a square against the -x axis side

help would be greatly appreciated

Eric

It looks like X is losing steps pretty reliably which looks to me like maybe a
step timing issue.

Is it possible that you dont have enough dir setup or hold time
or your step polarity is inverted? (which will throw off the dir setup and hold timing)

Thanks, I didn't think about that, I just left that page as is except for latency.

If I had my step polarity inverted, wouldn't it run the wrong way? everything works as expected ??

Eric

Just checked my timing numbers, I had left everything as originally found when I installed LinuxCNC and that was
Step Time: 50000
Step Space: 1000
Direction Hold: 1000
Direction Setup: 50000

when I re read the setup guide, it recommended
10,000
10,000
200,000
200,000
for the average stepper motor setup
HUGE differences.. Doh!

will reset these values and try again, but will also spend a few days re packaging everything better and maybe look for a new PC, this one has other issues.

thanks again, will get back If I still have issues.

Eric