Engraving Shifting to the right

[Carrol Fleming]

My laser head is nudging over to the right. It seems to be fine if I engrave on the very left or very right of the bed but if I engrave in the middle band the engraving nudges over. It started as drifting but is now quite dramatically jumping and the home position is moving.

The attached photo is from a trial on paper to test if I had made any difference with changing parts and cleaning.

I have done the following:

Extensive clean
Changed the white ribbon
Changed the encoder strip
Changed the x axis belt
Removed the motor and cleaned the teeth.

I submitted a support ticket to Epilog 24 hours ago but, other than getting the email confirming the opening of the ticket, I have not had a peep from them.

Thanks
Carrol

[Dan Hintz]

Likely a dirty encoder strip or strip reader...

EDIT: Posted too soon... the large jumps make me think it's the ribbon cable. You mention swapping it out, but honestly, the three things I mentioned are at the top 95% of the possible causes. You might have a failing motor, but the symptoms don't fit nearly as well as the stuff above.

[Carrol Fleming]

Thanks Dan,
I have changed the ribbon cable and the encoder strip. I have found that if I stick to the left or right of the bed everything is fine. If i use the middle of the bed it jumps and when it goes back to the home position that has moved. I am starting to veer towards the motor but wanted to confirm that that would cause this problem before I buy a new one.

[Dan Hintz]

Thanks Dan,
I have changed the ribbon cable and the encoder strip. I have found that if I stick to the left or right of the bed everything is fine. If i use the middle of the bed it jumps and when it goes back to the home position that has moved. I am starting to veer towards the motor but wanted to confirm that that would cause this problem before I buy a new one.

That steers me even more towards the cable... there's an open near the middle, which is why you get more spastic behavior when that portion of the cable is being bent roughly 180 degrees over itself.

[Carrol Fleming]

I will test the cable out again. There must also be a reason why it happened with the old and the new cable. Frustrating.
I have attached a test I have done to see where it kicks in. This time the home position did not change but on other occasions it has. The jump on the first block is also interesting, when i engrave an A4 size piece it does not move, only when the entire width of the bed is being utilized.
Regards
Carrol

[Martin Boekers]

If you put the blocks straight down the left side does it still do it or just in the center?

[Bruce Volden]

This vaguely reminds me of when my servo motor gave up the ghost! I believe I lost the Y axis and things looked similar to your pic. Lucky for me this was a known problem on the TT machines and I got a new beefed up version free of charge. Maybe something to look into--the servo motors aren't that bad ~$160.00 US if I recall.

Bruce

[AL Ursich]

To me this picture above points to a bad spot in the encoder strip because because after the error area I would expect the rest of the blocks to be off if the motor was bad. But the finish of the project was good... That tells us something...


Bearing problem?

AL

[Carrol Fleming]

I still need to test on a full sheet of engraving but it seems to be behaving in the center section now.

What I did:

Removed the (new) encoder strip and wiped it. Wiped the bar that screws on to fix the strip, generally wiped everything!
Removed the (new) white ribbon cable and blew on all the connectors. I even removed the clips that hold it in place and cleaned them! Turned the cable when I put it back.
Removed the linear head reader and cleaned inside the reader with lens cleaner and a lens cloth (this was advised by Epilog support who finally got back to me)
Reset the tension of the (new) belt.

Got a bit of a fright as when I replaced the linear head reader I did not tighten the screws enough and had a vibration causing a ghost engraving on the first test. That nearly pushed me over the frustration edge!

So far so good. It must have been a persistent speck of crud somewhere that I finally got rid of. Now to order new belts, cables and encoder!

Thank you to everyone for their help and advice.

Carrol

[AL Ursich]

We need a LIKE button on posts....

GOOD JOB !!!! LIKE

AL