This week’s assignment was to make something big with computer-controlled machining. I made a personalized hand-cranked gear calendar. I modeled the desigin KeyCreator.
I generated .dwg files and from keycreator and I used VCarve Pro to generate sbp files readable by the ShopBot machine.
VCarve didn’t like the detail in my gears. It discretized all the vectors so that the machine worked very slowly. Additionally, some of the paths were curiously in an opposite direction to neighboring paths.
The program also seemed confused about which parts of the gears were outside/inside my cutout, which resulted in a cutting path that did not preserve the desired shape of the gears. It solved the problem to set the machine to cut on the toolpath, but this of course cuts away some material from your cutout, equal to a full diameter of the bit.
All attempts to correct the toolpath direction in Vcarve proved futile. I tried:
1. Changing the bit to a 1/16 (I imagined that the program didn't like the thickness of the bit relative to the tooth size)
2. Joining all vectors in the modeling software (tuening them into one continuos length)
3. Joining all vectors in VCarve (by using the "Join" command)
None of these worked, so I went with the slow milling model, and significantly reduced gear teeth.
However, removing the offset helped center the wheels and remove discrepancies in the path. To cut the parts, I laid arranged all elements on a single plane before sending the job to the Shopbot machine.
I secured the gears with a bolt and nuts. The first nut allows for room for the pulleys to freely rotate, while the second one I is tightened against the first. VCarve was confused about which part of the gear was This is the final product. The gears are noisy but they rotate well. I still have to paint them to add finishes:day of the month and theme for the day. Another gear to indicate the month of the year would also be nice. I I would also like to paint it to add color features or varnish the wood.
