Sculpfun S9 offset when reengraving

[Nicu (Braic Nicolae)]

I have upgraded my S9 with limit switches and made some tests to how it’s working. Everything was fine except the fact that if I try to engrave the same thing on the same location it will be shifted like in the picture:

In the limit switch upgrading process I found out that I have an S30 motherboard and here are the parameters read from it:

What is strange is that the laser is seen by Lightburn to be returning at the 0,0 after each job, but visually it appears to return at the different location.

Does anyone has any idea why this is happening?

[parsec (FerAS)]

Run this file and post back the output.

Burn Offset LighutBurn 1.7.03

Given one picture and four words, I think @JimNM has nailed it. This test pattern helps identify mechanical problems: GrundTest.lbrn2 Scale it to fit the platform and run it as fast as it will go in Line mode with optimizations turned off and power set to mark a sheet of cardboard. Any differences from the design will be informative. Upload good photos of the result so we can look over your shoulder.

If found some difference:

Guide to mechanical adjustments and maintenance

[Ganitta28 (Roswell)]

It is possible that your belts are loose, that the belt pulley is loose, or that the rails are dirty.

[MikeyH (Mike Hembrey)]

Once you finish going through what @parsec suggested, let us know if you found a loose pulley or coupling.

If the problem is not solved, please describe all the steps you use to engrave over the same place a second time:

1. Home machine.
2. Burn part first time.
3. Check part, not dark enough.
4. Did not touch work part or any part of the laser.
5. Hit Start again, oops!
6. Re-Home machine.
7. Still in wrong place.

How did I do?
Just for information, enter $$ in the Console Window. Look for the $1= value and tell us what it is.

[Nicu (Braic Nicolae)]

I run the test at a speed of 4000mm/min which I think is pretty high for my S9 and I got this result:

Except for some wobbling, given by the device limitations I assumed, the test seems successful to me. I run it once more on a larger area and got the same result except for the wobbling which is less visible.

I made sure to cover the area in which I made the test from the fist pictures but I don’t see anything abnormal with the fist engraving.
By instructing the laser to go on the top right corner I can engrave the same thing again and again without a problem. The problem occurs when it has to go to the origin.

[Nicu (Braic Nicolae)]

I’ll be out of town for a few days but I will try to run the recommended tests as soon I will come back

[Nicu (Braic Nicolae)]

Checked the belts multiple times these days and tried to clean the device as good as I could but with no luck.

[Nicu (Braic Nicolae)]

In the end it was a mechanical problem. I had mounted some rubber bands to keep the wiring outside the path of the laser and even than they were pretty lose it seems that had applied more force than the sculpfun stepper is able to generate:

Removing the bands solved the problem.