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david schoder
02-05-2015, 12:37 AM
I have an issue with the laser cut lines not lining up properly,in the image you can see 2 examples,there is supposed to be a small bridge that holds the piece to the paper that gets cut in the end but the over run of the laser has been happening and it is messing up the project. I have cleaned the encoder strip (twice) checked alignment and that the mirrors are not loose.I have also closed the file,re opend it rebooted the laser and it is still happening. Any advise is welcome.
Thanks David
I have an Epilog 75watt ext. using corel draw x4

Mayo Pardo
02-05-2015, 1:40 AM
I can't advise you on Epilog equipment but in Coreldraw I would double check the nodes on your drawing while in wireframe mode. Zoom in close and make sure your line is ending where you think it should end.

Joe Pelonio
02-05-2015, 7:33 AM
I would suspect the movement of the head to be the problem. With power off, move the head manually all the way left and right, up and down and see if it's smooth. It could be that the rails need greasing, or even a sloppy (loose) belt. You can also tell by running a very small square, if it's better or OK, and the bigger shape does this then it's more likely to be the head movement at fault.

Bruce Volden
02-05-2015, 8:48 AM
I see you cleaned the encoder strip but also clean out the contrast reader the encoder strip sits into. It takes very little "gunk" in their to build up and throw off positioning off the beam. Another thing I would check is for any build up of crud in the valleys of the drive belts, I have had to use a fine brush and remove junk from this also.

Bruce

david schoder
02-05-2015, 3:45 PM
I would suspect the movement of the head to be the problem. With power off, move the head manually all the way left and right, up and down and see if it's smooth. It could be that the rails need greasing, or even a sloppy (loose) belt. You can also tell by running a very small square, if it's better or OK, and the bigger shape does this then it's more likely to be the head movement at fault.

The movement left to right is smooth,but moving it top to bottom it does have a bumpy feel in places not always in the same spot but if I feel it bump and then push back the other direction it does bump again right away.I did loosen and check the teeth of the belts yesterday and there was nothing stuck between the teeth that could cause it to skip, then re tightened the belts.
Does this sound like a bearing problem on the I Beam? My laser is 7 years old and I have not replaced any bearings on it,I am going to be replacing the tube (first time) in the next month as its only putting out about 30 watts. Funny thing is that pretty much everything else that I cut lines up perfectly. I did look closely at the file in Corel and everything seems to be in order with it. In the past I have cut this same file without any issues.
Thanks,David

Scott Marquez
02-05-2015, 8:25 PM
It sounds like a corrupt file if it only does it with this, can you re write a file?
Can you isolate it to one direction, X or Y, as it could be time to replace some bearings if things aren't moving smoothly.
keep us posted.

Joe Pelonio
02-05-2015, 8:31 PM
Try running the same file but smaller and in the upper right corner and see if any difference so the y axis movement is minimized. Also, put in scrap cardboard or something and run a big rectangle that takes up the entire area.
Watch the head as it goes on the y axis on the right. See if you can detect any visible slowing during it's travel. My bearings are original and 9 years old,
still no problems, but that doesn't mean yours are not worn out. You might even be able to remove and clean them if they have picked up lint or other debris.

Jeanette Brewer
02-06-2015, 10:31 AM
If you haven't resolved this issue and you haven't already reached out to tech support in Colorado, I highly recommend discussing this with them:

Contact options: https://www.epiloglaser.com/tech-support/technical-support.htm

joe claudio
02-07-2015, 12:26 AM
Alot of good sugestions,
i ran into similar issues ,, BOTH with Corell X5 and Autocad ......
the fix is .. make sure in your "app" .. CLOSE /join the lines The laser only does what its told to do .You have to look UP CLOSE .. how lines - meet up - intersect ... use the tools within the app ( corel/autocad) to make sure what u think you see , is what it is . YES .. zoom in 100% or more to see if lines meet .. this is real important when vector cutting . If the shape you "envsion" does not make a complete contiguis line .. " its Broken" ... It wonr provide the results you want ..
IMHO

david schoder
02-07-2015, 2:48 AM
Alot of good sugestions,
i ran into similar issues ,, BOTH with Corell X5 and Autocad ......
the fix is .. make sure in your "app" .. CLOSE /join the lines The laser only does what its told to do .You have to look UP CLOSE .. how lines - meet up - intersect ... use the tools within the app ( corel/autocad) to make sure what u think you see , is what it is . YES .. zoom in 100% or more to see if lines meet .. this is real important when vector cutting . If the shape you "envsion" does not make a complete contiguis line .. " its Broken" ... It wonr provide the results you want ..
IMHO

The lines are meant to be separated as to make a small "bridge" so when I am done cutting the piece does not just fall away from the rest of the sheet. When I remove the "bridge" the cut lines match up but are still off in other places. I cleaned the encoder strip reader today but have not had time to see if this has helped or not,it is about 30 minutes to run the whole project.
If I cant get it dialed in by Monday I will get in touch with Epilog and see what they have to say.
I have a feeling it is the bearings that run from the front to the back of the machine,when I push the whole I beam back and forward it is not completely smooth.
I have heard mixed reviews about greasing the bar or bearings on the EXT,I believe when I asked epilog about it on the phone one time they said it was not needed,it is definitely not in the maintenance section of the manual that came with the machine.

Richard Rumancik
02-07-2015, 10:45 AM
If you detect roughness in the gantry when you move it by hand, it definitely should be fixed. I was wondering, however, if your problem might be looseness in the pulley on the motor. If this happened you would get backlash and it would appear to be lost motion as the motor "winds up" before it grabs. So if you haven't alread check that the pulley is properly secured to the motor shaft.

If it is only a single file then I doubt this is it . . .

I would make a test file by drawing a group of geometric shapes (rectangles, circles, stars, polygons, etc.) and see if you can detect a pattern, as to whether they close or not.

david schoder
02-07-2015, 2:33 PM
If you detect roughness in the gantry when you move it by hand, it definitely should be fixed. I was wondering, however, if your problem might be looseness in the pulley on the motor. If this happened you would get backlash and it would appear to be lost motion as the motor "winds up" before it grabs. So if you haven't alread check that the pulley is properly secured to the motor shaft.

If it is only a single file then I doubt this is it . . .

I would make a test file by drawing a group of geometric shapes (rectangles, circles, stars, polygons, etc.) and see if you can detect a pattern, as to whether they close or not.

I have checked the tightness of all belts,they seem to be fine. the over shooting of the lines when cutting happens randomly,it is not always in the same spot on the file,which leads me to believe that it is not an issue with the file.Although pretty much every other file I run does not have an issue.
I can only think of one other file in the last month that had a similar issue.

Richard Rumancik
02-08-2015, 4:51 PM
OK, but I wasn't actually talking about belt tightness. Other people were. I was referring to the tightness of the pulley on the shaft. If there is a setscrew, for example, that is loose you will get random grabbing and loss of motion as it might rotate 5 degrees and then grab. It could stay that way for quite a while, then all of a sudden release and wind up 5 degrees the other way before it grabs again. The end result is that the endpoints of a shape don't connect due to the lost motion.

To check for pully looseness you probably need to take off the belt. You would need to lock the motor shaft (somehow) and try to rotate the pulley. Or you could just tighten the setscrew(s) and see what happens.

I'm not saying this is your problem but just describing the phenomenon. It will occur randomly as the acceleration/deceleration and sticktion are all unique to what is being commanded of the laser in a particular file. Some files might not have aggressive changes in direction. If the laser can follow the profile smoothly, never causing an instance of abrupt changes in load on the shaft, it will cut fine and join on the ends.

Since in your file you have a designed gap on the ends, the shapes are not intended to actually close up. This makes it a bit confusing to analyze. But try to see if there is a pattern. That is why I suggested some test shapes. Is it always the Y-axis that is over- or under-shooting? Then check the y-axis pulley.

david schoder
02-09-2015, 6:42 PM
OK, but I wasn't actually talking about belt tightness. Other people were. I was referring to the tightness of the pulley on the shaft. If there is a setscrew, for example, that is loose you will get random grabbing and loss of motion as it might rotate 5 degrees and then grab. It could stay that way for quite a while, then all of a sudden release and wind up 5 degrees the other way before it grabs again. The end result is that the endpoints of a shape don't connect due to the lost motion.

To check for pully looseness you probably need to take off the belt. You would need to lock the motor shaft (somehow) and try to rotate the pulley. Or you could just tighten the setscrew(s) and see what happens.

I'm not saying this is your problem but just describing the phenomenon. It will occur randomly as the acceleration/deceleration and sticktion are all unique to what is being commanded of the laser in a particular file. Some files might not have aggressive changes in direction. If the laser can follow the profile smoothly, never causing an instance of abrupt changes in load on the shaft, it will cut fine and join on the ends.

Since in your file you have a designed gap on the ends, the shapes are not intended to actually close up. This makes it a bit confusing to analyze. But try to see if there is a pattern. That is why I suggested some test shapes. Is it always the Y-axis that is over- or under-shooting? Then check the y-axis pulley.


Thanks for all of your replies.I spent quite some time today with epilog tech support,seems like it has been narrowed down to the y axis linear bearings.They are shipping out a new set,I will post an update after they are installed to let you know if this fixed the problem.

david schoder
02-13-2015, 2:07 PM
I installed the new bearings today,also did a thorough clean of all belt and pulley teeth,made sure all pulleys were nice and tight to their attached shaft. Now my Epilog is working perfect again,all cuts are lining up on the project that I was having issues with earlier.Thanks to epilog tech support,they were very helpful and took the time to walk me through any question or problem that I had.

Eric Allen
02-16-2015, 11:20 PM
Any idea which item you did that fixed the issue? Did you notice any of the pulleys loose? I have a kind of "surging" effect in the Y axis with mine. It has yet to manifest as a cut issue, but it does seem to draw a great deal of power in the three surge points as my office light dims a little when it hits those, might be kicking in the boost mode on the UPS unit to overcome the extra power required. I believe it also slows down a tad, so it's probably having the effect of giving more laser power in the slight "pause" as it overcomes whatever is causing it. I've been slowly trying to narrow it down to the item that causes it to require more power to overcome those points. The front bar that stabilizes the Y axis has been bent from day 1 of purchase, and I suspect it is timed with that, but haven't gotten to the stage where I have time to tear it down and verify. The issue hasn't manifested as a serious enough problem to require me to shut down, but once all my work is caught up I'd like to make sure it never does.:) The "surge" or drag points seem to be evenly spaced, so that narrows the field a little at least ...

Richard Rumancik
02-17-2015, 9:19 AM
Eric, if the stalling of the laser carriage is such that it dims the lights I'd say you have a serious problem. But I would never have thought that a minor stall effect would feed back through the power supply to UPS and then to the mains (reflected in the flickering lights.) The motors (whether stepper or servo) are controlled by pretty sophisticated drivers that control voltage and current under all conditions. It's not like a lone AC motor tied directly to the mains.

Are you positive that the UPS is operating properly and can handle the maximum draw of the laser? There are some rules for selecting a suitable UPS based on watts and VA (volt-amperes) of the laser; generally you have to have some good margin. I'd make sure the UPS itself isn't being overloaded. You can research this if there is any doubt. You might need to get some advice from Epilog.

Does your laser allow you to manually move the carriage and gantry around? If so, do you feel the binding points? I think I'd try to get this resolved before it affects something else.

Eric Allen
02-24-2015, 6:28 PM
The UPS is substantially overspec'd, I researched it heavily back when I was shopping. The hell of getting older, I remember very little of that research:) It doesn't register a load with just the computer, with laser and computer at max power it runs about 50% loaded. It's a nice sine wave setup, fairly certain all is good in that department. In spite of the lights reflecting the draw, it hasn't been enough to kick in the boost function, at least while I was watching. There are 3 consistent locations of obvious loading when moving the carriage by hand, several suspects come to mind.
My current lead suspect is wiring. I was running a similar cutting operation during the day yesterday and didn't notice the surging effect, if it was pure mechanical loading it should be more consistent with the obvious mechanical loading points day or night. You wouldn't think my LED shop light would be enough, but maybe it's that little nudge over the "line":) Tearing down the laser is easier than running a new line (major trusses to support the roof tiles and cathedral type ceiling for 15' to snake through), but I'm betting a new 12 guage line is probably the solution. Naturally, it's the longest run in the house, but at least no conduit requirement here:)


Eric, if the stalling of the laser carriage is such that it dims the lights I'd say you have a serious problem. But I would never have thought that a minor stall effect would feed back through the power supply to UPS and then to the mains (reflected in the flickering lights.) The motors (whether stepper or servo) are controlled by pretty sophisticated drivers that control voltage and current under all conditions. It's not like a lone AC motor tied directly to the mains.

Are you positive that the UPS is operating properly and can handle the maximum draw of the laser? There are some rules for selecting a suitable UPS based on watts and VA (volt-amperes) of the laser; generally you have to have some good margin. I'd make sure the UPS itself isn't being overloaded. You can research this if there is any doubt. You might need to get some advice from Epilog.

Does your laser allow you to manually move the carriage and gantry around? If so, do you feel the binding points? I think I'd try to get this resolved before it affects something else.

Richard Rumancik
02-25-2015, 11:29 AM
How old are the batteries? If the batteries in the UPS are still good I would have thought that they would prevent load changes from getting reflected back. Maybe you should do a test of the UPS with a different load. I would not suggest you do it with the laser; you could find another load that is 75% of rated and plug it into the UPS (instead of the laser/computer). Then turn the load on and off and see what happens. If you had a bad battery the smoothing effect of the UPS would be lost.

Also, you could unplug the UPS from the source and see if it is actually working as a UPS. That would give you an idea of battery condition.