I could not resist to try using Stefano’s superb BMG script for something practical
and now I am stuck at one of the first steps.
I want to drive a crown with an inner gear which is connected to a rod from its center to the center of the crown. So if the rod gets turned it forces the inner gear to roll and drive the crown.
Quite simple, thats what i did:
I built a crown gear with 60 teeth and the inner driving gear with 22. I generated
empties at each respective center and named them crown60 and gear22. I used the Spinner
script of BMG to generate the Euler transformations as stated in the BMG manual. I animated the inner driving gear to turn one degree clockwise each frame until frame 360. Works fine so far.
But i would like to drive the inner gear with a rod which has its bearing at the center
of the crown. So i added an empty at the crown center and called it rodcenter. Then i ipo
animated it to turn counter-clockwise 360 degrees during the 360 frames. Still works fine.
Then i parent the gear22 empty to the rodcenter empty and the fun stops:
My gear22 model gets dragged around and animates the crown, but doesnŽt turn itselfs anymore.
WHAT THE HECK AM I DOING WRONG?
If you are wondering what all that is good for:
I you connect gear22 with a stiff connection to a second gear (23 teeth) above it wich drives a second crown (63 teeth) right above the first (crown centers are own one axis) you will get a gear which transforms 231:1 with just four gears (!). As i find it difficult to explain why it does it i am making this animation.
You could use it for example to build a styrofoam cutter if you turn a plane using the
above mentioned gear. You also need a turning arm with the hot cutter thread. By using
two polar coordinate systems in your computations you can get to every point in your work plane with an absolute minimum of parts. The above gear will enable you to repeat positions down to 0.05 mm which should be even enough to drill PCBŽs if you want to. The idea was blatantly stolen from this PDF-file which also contains a rendering of the above mentioned gear:
“http://www.radixgmbh.de/media/50x_TanBo Bauanleitung Elektronik.pdf”
I tried this with Blender 2.37 and 2.36 using BMG 0.02 have downloaded 0,03 but it seems to add only save and load.