X Axis Positioning Problem

[Tim Earling]

I am having a big problem with my X Axis not lining up.

I recently replaced my laser tube and fans on my 45 watt Epilog mini (manufactured in 2004). I had to realignment my laser after the tube was installed. I also replaced a couple mirrors and lens, and tightened up my belt (the one that moves the lens carriage). Prior to this I did not have this X Axis issue.

So after this was completed, I made up a new jig for my projects. When I ran a job with my new jig, it did not always line up properly on the X Axis (I doing only rastering on this job). During a test run when I notice that the raster was out of line, I did an experiment and turned the machine off and on again and did a vector job to outline the shape of the piece I am engraving. I noticed the red dot pointer was not lining up. I repeated turning the machine on an off several times until the vector job was lined up - it took about 3-4 repeated tries like this to finally get it to line up. I made no other adjustments during this experiment and noticed for some reason the repeat of turning on and off the machine and sending a new job eventually resulted in the beam lining up perfectly. So every time I turn my machine off, I cannot be sure that it line up for my next jobs.

I cleaned the encoder strip and used an air compressor to blow out any dust that might be on the connections of the encoder strip.
Can anyone give me some suggestions on what I should do?

[Michael Evans]

Tim, the encoder strip doesn't have any connectors on it, so are you sure you are cleaning the encoder strip. The encoder strip stands on edge and vertically spans the length of the x axis engraving area. It is a clear mylar strip that looks tinted. This is what should be cleaned. After cleaning thoroughly, shine a flash light through it from behind and inspect it for clear spots. Clear spots equal bad strip. If strip looks good then flip the X axis flex cable end for end. ( thin white cable with black connectors that connects to the carriage read head and the the X/Y board over by the X motor ). If flipping the cable makes any difference what-so-ever , then that is the problem. I hope this helps and you don't have to go any deeper.
Michael Evans
Engraving Concepts

[Tim Earling]

Thanks Michael,
I will try this. I disconnect the thin white cable with the black connectors and blew them with some compressed air. I cleaned the encoder strip several times. I will check for clear spots. It's really hard to see the clear strip but will use a magnifying glass.

[Tim Earling]

Michael,
I tried the above but still getting the problem. The encoder strip looks clean.

[Tim Earling]

I was able to get this issue resolved.
I cleaned the encoder strip again, the belt, adjusted the tension belt, cleaned the x axis motor cog, cleaned the grooves in the tension belt, tightened the lens carriage, and blew any remaining dust off with my air compressor.

Note - I had switched my lens holder assembly from my Helix to my Mini (both 45 watt lasers and exact same lens holders - did this because my Helix lens is brand new). I did not think this was big deal, but it may have been the problem. When I put it back in, it rastered much better.