First, thanks for the answers about the hole drilling in glass question. That is pretty much what I thought (glass would fracture).
I have been cutting wooden gears on my cnc mill in order to build a wooden gear grandfather clock. I have chosen several different types of hardwoods and experimented with different cutters, feeds, speeds, etc. but I still get some amount of chipping on the tips of some of the gear teeth. I just had an idea. What if I mounted my small 25 watt Synrad to the side of the mill head (it is a very large bedmill where the head moves up and down about 16 inches of travel) and used the laser to scribe the gear outline to a depth of say 1/32 inch before I started cutting with the endmill. I need gears that are about 3/8″ thick in hardwood, so I pretty much can’t use the 25 watt laser to cut all the way through. Do you think this scribing would prevent chipping?
Just so you know that my questions come from interest but not experience. I have a Sherline CNC mill but mostly work with 6061 aluminum, a little 1018 steel, very little Delrin, and no wood. I am an optical engineer with a fair amount of UV laser micromachine design, including diamond marking, but very little CO2 laser system experience.
If you do part of the job with a laser and part with an endmill, by swapping laser and mill spindle, will you be able to match the cutting geometry for the two methods?
How fast can you cut through 1/32 inch of wood?
What is the diameter and divergence of the laser at the wood?
What prevents you from cutting through 3/8 inch of wood, in 1/32 inch steps if necessary?
Can you laser rough cut, slightly oversized, all the way through, then finish with mill?
The thought that came to my mind is might you be able to do it as 2 separate steps. Use the mill to cut the gear then used the laser to cut wood veneer then glue the 2 together?
As for your idea to scribe, it sounds reasonable but as already posted, can you get the 2 to register?
I *think* I can get good registration. The mill is extremely accurate. My plan is to have the CO2 laser on top of the mill and have beam delivery components (a sliding tube) attached very rigidly to the side of the head.
Making a wooden gear clock is a project I am also planning to do with my laser cutter. One thing you may want to consider doing is cutting the gears as 2 identical 3/16 pieces, then gluing them together. You could add a couple of dowels through the gears to ensure alignment of the two halves. Done properly, the gears would look and function almost identical to a solid piece. Using this technique, you could make the gears as thick as you wanted by building the thickness up in layers.
BTW, where did you get your wooden gear clock design?
I have talked to a few people who are excited about trying it. I want to use as many different types of african hardwoods as possible. I went to the local hardwood dealer and got samples of over 15 different types of very beautiful woods (including a bar of ebony for the hands). I have a problem planning wood to 3/16 inch thick though, and you can’t buy all these woods as veneers. So what to do?