MattGyver92

Of course. But they are (very) expensive, and some require a power supply to operate. For Gen 3, even flawed or blemished tubes can cost almost a grand.

Hmmm. It sounds like I'm going to have to do some more part sourcing. The product disappeared from Amazon several months ago and I haven't yet had any opportunity to test something else and update the instructable and CAD files. I'll make an announcement when I've managed to do this.

This is an extremely helpful write up.I've always wanted to construct a classical orrery and even went as far to model the gear trains in Sketchup and use the MS Physics plugin to simulate the mechanics (which is somewhat helpful). My main concern is the accuracy of the gears and having too much play in the movement.With a lot of the DIY orreries I've seen video of, the motion is choppy if not intermittent. My guess is this has to do with compounding play creating the sloppiness that lags the motion of the gears. I could easily see that becoming an issue with 3D printed gears due to the infill, texture, and expansion/contraction of the plastic from temperature. It could also be the way the power is being reduced from the source. I've seen orreries branch each reduction from the same dri...

This is an extremely helpful write up.I've always wanted to construct a classical orrery and even went as far to model the gear trains in Sketchup and use the MS Physics plugin to simulate the mechanics (which is somewhat helpful). My main concern is the accuracy of the gears and having too much play in the movement.With a lot of the DIY orreries I've seen video of, the motion is choppy if not intermittent. My guess is this has to do with compounding play creating the sloppiness that lags the motion of the gears. I could easily see that becoming an issue with 3D printed gears due to the infill, texture, and expansion/contraction of the plastic from temperature. It could also be the way the power is being reduced from the source. I've seen orreries branch each reduction from the same drive gear (leading back to nesting tubes for each arm) or starting the motion from the center at the sun and reducing for each arm consecutively from the previous reduction. My plan was going to be to wait until I have access to a laser cutter to get the best accuracy and possibly use acrylic rather than wood for the gear material, however if the the gears can accurately be cut with a scroll saw and the accuracy is still within tolerance, I might try to make them by hand (since I'd love to get a start on this). I definitely think I'd want to build and try your center measuring jig if it helps.I suppose if nothing works to get a smooth motion, I could resort to a more digital version using stepper motors for each arm and do the reductions in code. If each arm had it's own stepper, the planets could be programmed to a specific time or date input without needing to obey the ratios until they're in position. Although it would mean using 7-8 motors and I'm not sure if they can run continuously like that. Anyway, I loved the instructable and will read it more carefully when I have the time to double check my gear math and begin fabrication.

Now that's one hullsome breakfast.