Brutkey

Trammell Hudson
@th@social.v.st 🌐

Moving on to the drive mechanism, I'm testing the ST3215 continuous rotation servo turning a chonky 1.5mm worm gear and matching helical involute gear. The driver has an esp32-c3 built in so I can also use it for clock synchronisation.

Trammell Hudson
@th@social.v.st 🌐

I did mess up the constraint for the gear diameter so the end support was too close to the worm wheel teeth. A little subtractive manufacturing atop the additive fixed it so I didn't have to print another test fixture.

Trammell Hudson
@th@social.v.st 🌐

My new clock has an once per day hour hand and complications for the lunar phase, plus geocentric position of Mercury, Venus, Mars and Jupiter.

Trammell Hudson
@th@social.v.st 🌐

Starting on the big print for the base with a 72-tooth worm drive that will turn at 20 minutes per revolution to make the entire orrery rotate once per day.

Trammell Hudson
@th@social.v.st 🌐

The slowest speed in "wheel mode" for the STS3215 servo is still much too fast for the orrery's 20 minutes per revolution and the position mode doesn't allow wrap around, so I've made an outer loop controller that runs wheel mode once every ten seconds for a few milliseconds and uses the position feedback to stop at the right spot.