Hi Folks,
I found this forum during a web search on laser marquetry and simply had to join. Even though I just got here, the place feels like home already. Hope to make all your aquainances soon!
I purchased a laser engraver to enhance my woodwork. One of the things I like to do is marquetry. I have the basic skills down using the fret saw/scroll saw double bevel method but want to try my hand at some more intricate pictures using the laser to cut the veneers and hopefully speed the process up some. I have a 35W Epilog Legend 24TT and all the usual software (Corel 12, Photoshop 6, Photograv 2.11 etc.).
I've spend quite a while reading through tons of really informative and highly useful threads on the forum - many thanks to all you experienced laser/Corel experts! Most, but not all, of my newbie questions have been answered in the threads. Here goes with the two big questions (with lots of sub-questions!) that are still bugging me:
a) Laser "Kerf" and how to deal with it?
I made a very simple picture (a square, triangle and circle on top of each other) as a test piece. I vector cut the veneer pieces easily enough (one sheet of veneer at a time), but when I put them together to make the picture, the laser "kerf" (gap between the pieces) seems much larger than I was led to believe it would be.
I ran another test job with a bunch of vector cut lines, each one mapped (via color) to a different speed setting on the laser. I tested cuts from 20% speed in steps of 10% up to 100% (power was 100% for all cuts) and found that there is quite a bit of difference in the kerf width. As expected, the 100% speed / 100% power cut gives the narrowest kerf and easily cuts the thin veneer material. I measured it at about 5 mil on the top of the veneer and about 3 mil on the bottom. Why is it thicker on the top?
I had ran the initial test piece using 30% speed / 100% power, so the kerf was about 15 mil per the second test - no wonder it was "sloppy" marquetry! I re-ran the square/circle/triange job using 100% speed / 100% power, but even with the narrowest possible kerf, the gap is really too big for good quality marquetry.
I imagine that some of you have already come across this issue and solved it. The solution I plan to try is to increase the size of the inlaid piece by a fraction (how much? how to do in Corel Draw 12?) so that the pieces fit snugly together. Is there a simpler way? What am I missing?
b) I have the rotary attachement for my laser, but it's only any good for round objects up to about 6" in diameter. That will work fine for vase-like turned objects, but most of my turnings are much larger bowls/vessels.
What I think I need is a turntable rotary attachment, and another mirror (prism?) to turn the laser beam through 90 degrees. Then I could use the z axis motor (table height) and rotary turntable to engrave stuff all the way around much larger diameter bowls.
Has anyone done anything like this before? I realize it would probably be very difficult, requiring firmware changes in the laser as well as driver changes on the PC. Is this something I/we should lobby the laser engraving machine manufacturer's for?
Cheers for now,
Dave