Twelve prints later, the outer zodiac ring is complete and we can see how it looks in the dining room. Now I need to finish the constellations and find a globe, disco ball and sun.

Went to see Cats (2026) last night. I loved it. It was much better than Cats (2019). I'm going to see it again and again.

Mr Pythagoras grudgingly allowed a test print of the 12-piece zodiac ring.

The new moon ring gear looks mighty fine and is much more rigid! It makes one rev every 29.53 days and has 28 spaces for shiny moon phase indicators to be installed

Maybe it's just bad filament or K factor settings? This gold pla seems to work fine.

wtf is this from the debian forums?

The one that worked fits quite nicely however!

It has not been a good day for our printer.

FreeCAD's constraint solver helped me find the angles for this complex bracket and it worked on the first try (once the printer successfully produced one). Those aren't nice 30 degrees; they are 34.9 and 25.1 because of the 20mm offset in the axle spacing and the need to meet up with a T bracket on top.

Life uh finds a way

I walk away from the printer for ten minutes and look what it does. "Printing completed" no it's not.

One of my favourite climbing gyms is being torn down to build apartments near Sloterdijk.

The additional structure and webbing on the ring gear really improves rigidity and makes the entire mechanism turn so much more smoothly than before. I'm still experimenting with how to display the moon phase on the ring, which is why each one is a little different (and the colors are random)

The printer skipped a step or something on a middle layer, leading to seven thousandths* of runout on this gear.

*: Of a meter.

I do wish FreeCAD had a way to add text labels, other than on dimensions. It would be very useful to be able to annotate complex sketches to explain why things are laid out in certain ways.

Business on the right, party on the left.

Since I'll need to reprint the big ring gears to make them more rigid, I can also apply some lessons learned and redesign the gear train to eliminate the enormous 85 tooth zodiac gear.

That's better! Added some decorative webbing and now the deflection is about 1/8th what it was with the old ring gear design.

Doing a science to try to quantify how much flex different ring gear sections flex.

The larger multi-piece ring gears are more sqooshy than the single piece versions and this is making the mechanism jump rather than rotate smoothly. With a 2kg weight, the moon ring deflects from 66 to 61cm, about 92%. Going to try making a version that is more resistant.