Quartex Q-80 24 hour gear set

thingiverse

The Quartex Q-80 is a clock movement available from klockit.com. They used to sell 24 hour movements (where the hour hand took 24 complete revolutions of the minute hand to make a single revolution) as well as normal 12 hour ones, however they recently discontinued the 24 hour ones. It turns out that you can quite easily replace the last two gears to recreate the 24 hour movement. These two gears replace the two that drive the hour hand and reduce the gear ratio by half. Printing these are, unfortunately, quite a challenge. FDM printers almost certainly won't have enough resolution to manage it. The Form 3 is able to print them acceptably, but the challenge is removing the supports without causing any damage on the teeth. To that end, it's important to print these flat relative to the build plate. Tilting them at all will require placing supports on the teeth, which just won't work. You should manually place the support touchpoints. Place 3 of them equidistant around the center hole and place 6 of them near, but not at, the base of the teeth around the outer edge. I printed these in clear resin not because I desired the result to be translucent, but that the clear resin does the best job at reproducing fine detail. No post-processing is required beyond washing and curing. If after removing the supports the bottom surface is not smooth then some light sanding may be helpful. The movement will have maximum torque available on the hour hand, so even if the result seems to stick a bit it should wind up working just fine.