stair steps in cut edge

[Eric Mims]

this didn't show up for some reason.. I'll try again..

Cutting some .125" aluminum, testing a bit and took several passes to pocket out a shape. Noticed these stair steps after I cleaned out all the chips. If you were looking down at the piece from above, it seems like the bit moves left and down each time it moves down in the Z (moves neg. Y and neg. X each step). You can't see it in the pictures, but the other sides of the pocket are clean, with no steps.. I assume because the final pass is cutting full height because of the offsetting that is going on.

I though maybe my piece was being held at an angle, but that wouldn't matter, it would still cut straight. The piece was screwed onto a table and definitely wasn't moving.

What is out of whack here, and how can I measure/adjust to fix it?

[Joey Jarrard]

let me know what bit you are using also send me the file and g code it might be a smoothing or a step over. let me know

Cut

[Eric Mims]

sent you an email with it attached

[GJMATHEWS]

this didn't show up for some reason.. I'll try again..

Cutting some .125" aluminum, testing a bit and took several passes to pocket out a shape. Noticed these stair steps after I cleaned out all the chips. If you were looking down at the piece from above, it seems like the bit moves left and down each time it moves down in the Z (moves neg. Y and neg. X each step). You can't see it in the pictures, but the other sides of the pocket are clean, with no steps.. I assume because the final pass is cutting full height because of the offsetting that is going on.

I though maybe my piece was being held at an angle, but that wouldn't matter, it would still cut straight. The piece was screwed onto a table and definitely wasn't moving.

What is out of whack here, and how can I measure/adjust to fix it?


Hey Eric, did you ever get this figured out?

[Eric Mims]

I haven't noticed the problem again, but I have to say I need to find that exact same file (it was a test file) and run it now that I changed the drives. I will try to do it today or tomorrow and let you know. I have not run alot of aluminum since those tests, since they kept messing up... I'll do some more tests soon.

[james mcgrew]

did you change the x and y gecko's?

jim

[Eric Mims]

I changed the daughterboard for the opto-isolator.. I didn't replace them with the other drive. The Z is still the other drive. Will test tomorrow and report back.

[james mcgrew]

as long as you did the gecko oto thing you will be ok, mine has not lost a step yet. check this out

[Eric Mims]

Well I hunted on my computer and actually found that exact same file as the original post above. I tested it with the XY geckos (no daughterboard, changed back to 201s) and the Keling drive in the Z and the results were perfect, as perfect as can be seen by the eye. No stairstepping at all.

This file had a very tight, fast spiral as it entered the piece and it may have exposed the same errors that everyone Z drive was showing before. But with the drives changed, it seems great.

I'll be doing a project hopefully soon in thicker aluminum.. I'll post some images when it happens.

[james mcgrew]

eric every one whos has changed the drives has eliminated the problem another one "dax" in fla finished his today!

jim

[GJMATHEWS]

as long as you did the gecko oto thing you will be ok, mine has not lost a step yet. check this out

Jim, that dustboot is incredible. Kudos!

[Eric Mims]

I know, it's good to know it seems to have also cleared up this less common XY stepping problem too..it only seemed to show up in examples like I posted in this thread. Looks like we're all cruising now!

Eric



eric every one whos has changed the drives has eliminated the problem another one "dax" in fla finished his today!

jim