I put a 2.5W laser on the machine quite some time ago, it has come in very handy for layout work and marquetry.
The other day I was trying to cut some smaller "coins" and was just not satisfied with how they were turning out. Difficult to see what they were and any detail. I was using a .031 dia tapered ball nose. No matter what I did, just not all that good. Then it hit me, why not try outlining those details with the laser? Here are two examples:
This is what one of them looks like before laser outlining:
These are two inches in diameter. It makes a huge difference. The total depth of these models is about .125 on a dished shape. Before outlining the dragon had no eyes or nose, same with the dolphins.
The process was pretty simple once I had the machine set up properly. The picture below shows the laser unit mounted on the Z axis:
I took some time and got the offset figured out very accurately. The easiest way to work with a setup like this is to use "workpiece offsets" in the machine controller. They are usually G54, etc. That makes it easy to switch between zeroes by just clicking a button. A shout out to Ger21 and his Screenset 2010, he designed it so that it makes it really easy to use those workpiece offsets. Best darn $20 I ever spent!
I use Corel X7 to add the vectors for laser etching. But Aspire will also do it. It is just that I am very used to Corel having used it since version 1.0.
These small lasers have very long focal lengths, mine is about 6 inches. What that means is setting heights is not at all fussy. I set up a laser post that does not output any Z motion at all. With the long focal length a difference in height of .125 makes no difference in results. I also assigned G59 (workpiece offset) to the laser so I do not have to mess with it.
What I have been doing is cutting the model leaving about .003 on it. Then I laser it. Then I recut it to final height. The reason is that the laser darkens the area around the laser cut line a bit. The cut is quite a bit deeper than .003 so the second cut cleans it up nice. BTW, I sort of goofed up on the dolphins. I changed my Y zero on the cutting but forgot to change the Y zero for the laser. A total of .015. So it is not as good as the Dragon. Live and learn -or- another case of old guy syndrome.
Smoke collection: That shoe is hooked to the dust collector. Mine has a pleated cartridge. Interestingly it sucks up the smoke and filters it right out. I cannot smell any wood burning in the shop and I have a very small shop, about 14 X 28. Evidently the dust cake catches all the smoke. I built the shoe mostly to shield the beam because it is not good for the eyes at all. It just slips over the Kent dust shoe mounting plate. I may get around to building a magnetic one.
Originally I started out wanting to cut "coins" about 1.375 in diameter, with the lack of detail in those cuts I bumped up to 2 inches hoping to get better results. Looks like I can go back and try 1.375 again.
Happy New Year Everyone!