Hello all! I have an issue that just started today.
At 3pm today, I printed an 11x14 photo and all went well. After the print was done, I turned the machine off and cleaned all the lenses. Noticed the carriage tray seemed to move stiffly right/left but I left it alone and put everything back together.
I then proceeded to make a second copy of the 11x14 print I had just finished. This one cut out at 11x14.25 instead of 14.
Proceeded to check belts on the carriage plate, cleaned the wheels, check the tension, cleaned the assist fan since I had the plate off. Put everything back together again. Still cutting too large on the left/right axis. Adjusted tension several times, no luck.
Decided to run the gogm since I know GF will want that. Here’s a photo of one done just now (bottom) and one that I ran a while back (top)
Notice the new one is wider and the circles didn’t cut properly.
Anyone have any clue what I need to check next? TIA for any help you can offer!
You have a problem with the motion components that move the laser head. Check that all your belts are the same tightness, free of debris, and all your pulleys and gears are clean and moving freely.
Make sure you do not move the head or gantry with power on.
I have made sure that everything is clean. Pulleys don’t appear to be cracked.
Whatever is going on is consistent. I scored 10 rectangles, 1 at a time, measured after each one. The rectangle was supposed to 10in x .25in. it measured 10 5/16 x .25 on all 10 attempts.
I then tested running some but decreasing the width to .9696 of 10in and my resulting rectangle was exactly 10in when scored.
So for some reason the x-axis is off the same amount each time…seems like it could be more than just a belt/pulley/cleaning issue
Then it’s a belt tension issue. If cutting a square ends up with one axis longer than the other, the belts aren’t the same tension. This will also cause circles to be elliptical.
I don’t want to seem argumentative, as at first glance it would appear to be a belt tension issue, but I’ve been pondering this on and off since you posted.
If it was a belt tension issue on the X axis, then the engraves would be blurred, as every pass in opposite directions would be offset. They appear in your picture to be just as clean/sharp as the original.
Could you print the GOGM rotated 45 and 90-degrees? You can copy and paste in the design, hold shift while rotating to “snap” to 45 then another to 90.
I will print the gogm as you have suggested and post the results.
I also wanted to post this image as well. After figuring out that I could work around the sizing issue by changing the x-axis size I decide to redo my print just so I could still get my order out.
The cut was spot on to 11x14 (after my changes) and the text engrave looked good. Engraving the image showed some issues with banding. There is noticable difference every 2.5in in the image. You can see it in the attached photo.
My belt tension seems to change as the carriage plate moves. I can feel the plate get harder to move then get easier. When I can feel the tension get stronger, there is less slack in the belt. Is that possibly a bad wheel or a bad belt?
That might point to a flaw in/damage to one of the carriage wheels. You would have to remove it, which is a bit of a pain, and very carefully inspect each of the four the carriage wheels.
I have had the carriage plate off and have inspected the wheels, they do not appear to be worn or cracked or broken in any way. When there is not tension on the belt, and the carriage plate is back on the rails, it moves smoothly and doesn’t appear to “hang” in any particular spot like it does when there is tension on the belt. Is there something else I should be looking for?
The only wheel I haven’t had a good look at is the left side belt wheel. The one that is likely the drive wheel for the carriage plate. I assume it is connected to the motor and I would have to take the motor off to get it out.
Hold off on the GOGM prints. I have some thoughts on a different test, I need to create a test file. I need to get some sleep and take my dog to the park. I’ll post up again later.
If the belt is still operationally tight but of a different tension than the Y belt you will get exactly the behavior described. Engraves will look fine, just stretched. You will get offsets only if the belt is really loose.
Belt tension is something I worked with on my 3D printers. If the tension was off on a belt, the test article would be larger or smaller in that axis.
