Epilog cuts weak in lower right quadrant

[Kev Williams]

OK, I re-read Steve's post, all squares in the lower right have trouble, so it's a 'whole table' issue, not a 'per square' issue-

My 25w ULS had that problem before I changed out the laser tube. My rep said the problem was likely the laser itself needed alignment. If the beam isn't perfectly straight and level to the gantry and mirrors, then the farther from the beam orifice the mirrors get, the more the beam misses the centers of the mirrors.

I test my beam alignment using tape. I put some tape over the hole in the cover next to the each mirror from the beam-in and beam-out side (one piece at a time), then run a test at the 4 corners using about 30% power. I note where the beam burns the tape in relation to the mirror, then go to the next corner. Then I check where the beam hits the mirror above the lens, and at the bottom of the lens itself. The burn points always vary slightly, but not enough to warrant moving my lasers-- yet! I did find my red LED was mounted skee-wampus, the red beam was hitting the mirror frame above the lens instead of the mirror itself. Aligning the led made it much brighter and sharper.

[Steve Stram]

Steve (OP), when you did the test of the four corners with the 6" squares of 1/4" thick ply, where did you focus each piece? Did you focus each test piece individually at their respective corners of the table before cutting them (and refocus for each piece at each corner)? Or did you focus the laser in a single location (upper left corner of the table for instance) and then try to cut each piece at each corner of the table? If you focus the test piece in the lower right corner, will it cut properly? Likewise, does the upper left piece now fail to cut through when the focus is performed on the lower right piece?

Good point, I focused in the upper left since that is where the machine goes to in focus mode for full sheets. I will try focusing at lower right and adjust speed for complete cut through. Then cut all and see what happens. It will be interesting if a different speed is needed to cut through there.

The table is 1/10" lower in the lower right measuring from the top of the carriage sheet metal cover. I'm not sure if the sheet metal cover is exact to the gantry travel, will look into that. Just a couple screws. What is "significant?"

From Ken "Have you tried reversing the direction of the cut to see what happens? Or the starting point of the cut?" That will be a new lesson for me. The lasers run from Corel, how do you designate the cutting sequence in Corel? That could be good information because the laser works from upper left to lower right normally. Not sure if it can get "tired" over a 30 minute cut time or something heats up in the machine.

Also, it is most extreme in the lower right corner, but the affect is gradual from the table center to the lowest right bottom corner. The affect is minor on the far right top and lower bottom left.

Steve.

[Mark Ross]

Assuming there is no warping of material...

1. Check laser alignment over the full table.
2. Make sure the laser is leveled.
3. Make sure the work area is level.
4. We have Epilog 36 EXT's and yes, the mirrors do wear out. If all mirrors are the same like they are on the 36 ext, swap the mirrors around. If the problem moved, chase the mirror.
5. Laser tubes age, but what we normally see is we have to slow the entire job down.