GearHeads Corner

Finally got around to mostly finishing my orrery a little while ago (um, "decision paralysis" is the bane of my existence). Since Gearotic was key in helping me select completely insane Modules for these gears (to maintain a single center distance for all gear pairs) I figured I'd make a quick post...

...see attached file...

...I haven't finished off the central planet gear stack (trying to decide if I just pop a white disk on, or try to do something fancy) so that's why you can still see a bit of brass at the center of the planet arms. Laser cut acrylic; the Saturn drive gear is approaching the minimum resolution of the material (smaller than this and you just get a fused lump) while the Saturn planet gear is approaching the maximum size of my laser bed, so I skipped everything past Saturn.

I claim this is defensible since Uranus and Neptune would barely move, even if I had included them. There's some barely visible fiddly bits down on the base (approximate flight directions of Voyager 1 & 2, plus the Pioneer probes, and some things like line of galactic rotation, some of the Zodiac buried under the main planet gear stack, and so on).

EDIT: alright, got a sane file size...

Looking good you CNCing the gears?

Lasered the gears, which is now my favorite way of generating gearing that isn't going to carry big loads -- fast, accurate and tidy. Plus it becomes really easy to prototype -- the exact same design file can be used to cut cardboard as well as the final acrylic.

For really thick materials the kerf gets a little wonky (the laser edge isn't perfectly straight up and down, but more closely resembles a sharp \/ which in turn means the gear edge can be either \ or / ), but I take care of that by simply flipping the orientation of mating gears (so a \ edge gets paired with another \ edge, making a nice \\ tight match rather than /\ or \/).

...if that makes any sense? The kerf angles really only come into play on thick items, but since the materials are extremely consistent, the kerf angle is equally consistent and thus easy to deal with in design.

Great job on the orrery Mand, job well done and thanks for sharing. Congratz

Cheers
Bob
:)

+1