Thought I would post a few reflections on building the SP8 Coup Perdu and a video of the completed clock.
When Steve released the SP8 I knew I had to make it as I thought the auto-rewind feature was awesome (still do). Bought all the components, put the old modified Ender 3 to work and soon had a bunch of clock shaped parts. The frame was printed from Hatchbox wood, the gears were multi-color filament straight from China and everything else is just from old filament I had in stock.
The instructions were excellent, so the clock went together easily and worked right off the bat. Unfortunately, it would run a day or so and then stop. Tried a few things without much success and then got busy with other things so the clock went on the back shelf. Fast forward to a month or so ago and a fellow was building one of Steve's clocks in another online forum. I felt some embarassment with my half-working clock, so it was time for a debugging session to make it live up to it's full potential.
First, I dissembled the clock. The clutch on mine was really tight so a few winds of the coil spring were nipped and then it was much easier to adjust. All the wire gear arbors were checked to make sure they were still straight. I tried some lithium grease on the escapement but that made things much worse so all that was cleaned off. One of the gears had a single layer of elephant footing on one side from a probable Z offset issue, so a file was used to remove it. I did use some dry graphite powder for lubrication inside the gear arbor holes and a little was rubbed on the escapement.
Not sure exactly what the fix was but it is now running reliably with no pennies in the battery box. I also deleted the second hand for a cleaner look and printed and installed the back weight so the clock would hang nicely off a single screw for a wall mount. Here it is running great in it's permanent location:
Years ago I was goint to tackle a wooden clock using gears made by hand with a jigsaw. Luckily I never did that and got into model engineering instead. It's much less stressfull to make accurate gears with a dividing head on the mill! 😀 The CNC controlled hot plastic gun, aka 3D printer, also seems to do a decent job and this project allowed me to scratch that clockmaking itch.
About the only suggestion I can offer is that it would be nice if the clock dial was completely seperate from the clock frame, perhaps attached with pins or magnets. That way a builder could change clock faces much easier without dissembling the clock and maybe without removing the hands. You could also crank-up the layer resolution for a fancy dial without having to spend hours printing the bland clock frame.
I had enough interest in the electromechinical clock that a month ago I ordered a couple of the electronic workings and they are on route to me via a very slow boat from China. Since ordering the stuff, I'm beginning to think a weight driven clock would be more interesting, especially the newer models like SP13 or the very large SP12. I like how you incorporated lessons learned from previous models. Got too many irons in the fire, however, so it looks like long-term running of the SP8 will be the only clock project for now. I think I can obtain a min per week accuracy (almost that now) and I think that's pretty good.
I wasn't aware PrusaSlicer had a split function like that as I've been using Cura for a long time.
Thanks for posting such a detailed description of your process. The colors look really great, especially the gold lettering.
I recently had all of my clocks on display at the Bay Area Maker Faire. Many of the clocks had been in storage, and it was an oportunity to see how each design performed again. The deadbeat escapement of this clock ran flawlessly, while the Coupe Perdu was one of the least reliable. The biggest surprise was the electromechnical clock. Usually, it is a bit fiddly, but it also ran flawlessly for the duration of the show.
You could possibly split the dial away from the front frame using PrusaSlicer. It even has a mechanism for adding dowel pins that should be able to be sized to fit small magnets.