GearHeads Corner

User Video Links => User Photo's ( Show and Tell) => Topic started by: Mand on September 09, 2019, 01:17:47 AM

Title: Mercury-to-Saturn Orrery
Post by: Mand on September 09, 2019, 01:17:47 AM
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 completel y 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 approachi ng the minimum resolutio n of the material (smaller than this and you just get a fused lump) while the Saturn planet gear is approachi ng the maximum size of my laser bed, so I skipped everythin g past Saturn.

I claim this is defensibl e since Uranus and Neptune would barely move, even if I had included them. There's some barely visible fiddly bits down on the base (approxima te flight direction s 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...

Title: Re: Mercury-to-Saturn Orrery
Post by: Nic Bwts on September 13, 2019, 06:11:55 AM
Looking good you CNCing the gears?

Title: Re: Mercury-to-Saturn Orrery
Post by: Mand on September 14, 2019, 02:17:24 PM
Lasered the gears, which is now my favorite way of generatin g 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 orientati on 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 consisten t, the kerf angle is equally consisten t and thus easy to deal with in design.

Title: Re: Mercury-to-Saturn Orrery
Post by: BobL on September 15, 2019, 11:54:39 AM
Great job on the orrery Mand, job well done and thanks for sharing. Congratz


Title: Re: Mercury-to-Saturn Orrery
Post by: BMeyers on September 19, 2019, 04:57:06 AM