After the discussion on Gearotic earlyer I thought I would share how I design my clocks. It applies to both CNC and laser clocks.
First I cut all my gears with a 1/4 hole for the shaft to start. This way they fit on standard 1/4 bolts.
I start with a platform I built. It has 400 5/16 holes spaced 1/2 on center. With the 1/4" bolt in the 5/16" hole I can mesh just about any gear or gear combination as shown here.
Attachment 175254
When I cut my gears I also cut several spacers out of the same material. I also have various 1/8" spacers that I cut with my laser.
It thakes me a couple passes working from one end to the other but I eventualy get my train working pretty good.
I also have some pointers shown here that allow me to test the ratios to make sure Im getting the correct revolutions.
http://www.youtube.com/watch?v=rtyyMagFx4s
This is important as on the last clock I was useing the wroing gear and after marking off my minutes and hours I caught it before I had designed my clock carcas.
This clock has a combined hour and minute gear train (big gear in center) with a seperate second hand. This is the back of the clock. The hands will be attached to the shafts in the front once the carcase is designed.
http://www.youtube.com/watch?v=CXA2X0nPzwE
The upper most wheel is the second sweep and each gear is one second. This makes it easy to drive it with a spring and Escapement, stepper or motor.
Once gear lay it is fixed I go back to corel and remove all but the holes used and I have my cut out for my carcas.
I never make wieght driven clocks. Its very hard to build one that doesnt require winding every one or two days. Believe me no one wants to wind a clock every day. I use spring windings, motors, or other.
Since I now have a CNC and laser I can easily dublocate the designed clock in what ever material I want. This one was built out of MDF just vecause I had a bunch of 1/2" material laying around. If I were doing it with the laser I would cut 4 sheets of 1/8 stock and laminate them or just keep the clock thin if done in acrylic.