Focus problem when rastering only??!!

[Mohammed Issa]

hey all,

so i have finally received my chinese laser a week ago. (i promised i will post pictures and advice for buying from bodor, but i didnt get a chance, because i was blessed with a new baby boy a few days ago!!).

here are the specs:
60 watt laser tube
work area of 500mm*300mm
up and down table [15cm]
red dot
rotary attachment
honeycomb table (and stainless steel)
laserworks v5 for the software

i have been playing around with it for the past few days, its been a good machine (with a few initial problems that i will post in a separate thread) but after sorting through the few problems, it worked fine for a while.

i decided to make some veneer business cards (i bought some from leevalley.com -- http://www.leevalley.com/en/wood/page.aspx?p=32820&cat=1,250,43217 )

i made a simple design for my card, i decided to make some of graphics rastered, and some vectored. (in the chinese program, its scanning and cutting). so when i did the vectors, they looked focused and sharp. then when i did the rastering, it seemed to be out of focus. (when i say out of focus, i mean you can sort of see another shadow for the word being lasered behind it) i have no idea why this happened. i tried cleaning the optics, i made sure the laser hits the middle of the last mirror, and i also did the focus test (i peice of wood raised 2" from one side, and the thinnest line is the exact correct focal distance required (6.6mm).

the veneer is very light and cuts very nicely, but again, when i raster, you can barely read the writing. any ideas whats going on?

for rastering, the settings were 500 speed and 15% power
for vectoring, the settings were 500 speed and 10% power (any lower than 500 will cut the card)

i will consider any suggestions!! i will post a picture soon

thanks in advance!

[Mohammed Issa]

so here is the card i was making:
251591251592

you can see that ENGRAVEIT, my phone number, and my email are in cut mode, so they are fine, but for example, my name, and the "Laser engraving services" are in scan mode, and they are not sharp as they should be.

the whole card was made at one time without moving it at all.


any clues? suggestions?

[Ross Moshinsky]

I believe those machines work best at 400mm/s for engraving. Also what was your scan gap? You want to raster at about 500dpi typically which is about .05 scan gap. That will impact the quality of your engraving dramatically. I find engraving at under 300dpi (except for photos) to be unacceptable.

EDIT: I don't think the scan gap is the issue. That looks like an issue with the machine jumping teeth or something. I'd try running the job slower and engraving only in one direction.

I'd also look to make sure none of the mirrors are loose and that the belt is of the correct tension.

[Mohammed Issa]

im not sure actually, i will check/try and get back to you..
thanks ross

[Mohammed Issa]

Thanks a lot ross, that did solve the problem, it was set at 0.035, changed it to 0.05, looked a lot better!! i posted the finished product in a new thread, if your interested in the final result.


thanks again!