The clock runs fine but I think the weight shell should be modified slightly to make it a bit stronger. I found the hard way that if I drop the empty weight shell on my tile floor, the top "cheeks" will break off clean at the level of the bottom of the wheel groove. This actually happened to me both times I dropped it so I can say so far it breaks every time I drop it. I realize I shouldn't drop it but it happens. The existing web that takes the load from the axle hole into the shell wall does not extend that low and the gussets below the floor of the groove do not add any strength to the sides beyond the floor of the groove at the level of the floor so there is no reenforcment of the shell in that area. I reenforced the one I had made by pouring a little epoxy in to puddle in that area along with a patch of fiberglass cloth. But I will add some vertical ribs on the inside in Orca Slicer for the next ones I make. By the way, the new "scarf seam" feature in the latest Orca Slicer allows forming the shell with a very smooth surface and minimal visible seam, without the pitting effect I get using "random".
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More on the string breaking. While the string on my grandson's clock did break, the situation was not witnessed by anyone but him and it is not really clear what happened. My initial testing of the line involved using a bowline knot to make a loop at each end of a sample with the loops going over 5/16" rods (somewhat similar to the hook on the clock frame). In that situation the line broke at 20 lbs but appeared to break on the length between the knots, not at the knots. However, given the confidence of the company engineer about the strength of their line and his concern about its sensitivity to knots and small radius attachment, I tried testing with the line simply wrapped around a one inch pvc tube at each end of the test string with no knots or smaller radius. That setup allowed the line to exceed the rated 65 lbs before breaking. So the line works as advertised but applied to the clock with knots and the small radius hook on the clock frame (a screw on the 32 day clock) there may still be concern that this line does not offer much of a safety factor and maybe a stronger line should be used (at least with eight year olds involved).
About the string breaking, I contacted the maker, Innovative Textiles in Colorado, and they called me back very concerned about this issue. They requested that I send them a sample of my reel of string and offered to supply a new one to me. They are confident that their string should be stronger than 65 lbs in a pure tensile test. So we will see how that works out.
I have not tried the scarf function on gears but I think it would work well on the "gear 0 pallet" and the winding drum, and probably on the "wacky gear" types with continuous curves. However, I was planning to try simply "painting" the seam for the conventional gears as on the moon phase clock in a non-critical location such as the lowest point between two gear teeth. Orca allows the user to paint the location of the seam.
I really enjoy building these clocks. Clearly the weight shells have been adequate for the intended function, and we shouldn't expect clock parts to survive being dropped on a hard floor. But it does appear that just extending the ribs below the axle hole to a point below the level of the floor of the pulley groove would significantly improve the strength of the weight shell in the hands of someone clumsy enough to be dropping it. That occurred while I was polishing the weight shell. I had printed that one with "random" seam and was trying to improve the finish which ended up with all the pock marks and looking a bit like ostrich hide. I can polish the silk copper filament objects to a fine gloss that looks very much like polished metal but the seam marks don't go away. So now I just use the scarf function. I am doing a weight shell design externally the same except for longer ribs inside and closing up the sides of the pully slot somewhat (which obviously complicates putting the string around the pulley a little). Will see how that works. Maybe even drop test it.
Ironically while writing this my eight-year-old grandson managed to break the "Power Pro Red" 65lb test string while winding his clock and dropped the loaded weight shell on his hardwood floor. That weight shell shattered as would be expected dumping several pounds of steel shot all over the floor. But he and his sister had considerable fun cleaning them all up using magnets and are still playing with the magnets and shot in the bin where it is collected. That weight shell burst from what amounts to internal hydraulic pressure fracturing in the middle of the cylinder but both the top third of the shell and the bottom section (one extension) survived intact. The main fracture lines run vertically along the long axis of the tube (and not much on layer lines), which is how a pressure vessel normally fails from excess internal pressure. That does suggest that the basic design and wall thickness are plenty good for handling the weight of shot and hanging on the string. The issue there was the string. Surprising that 65 lb test string would break (and not at a knot or around the screw holding it on the frame of the "32 day clock"). So I tested string from the same spool as used on that clock and found that it breaks consistently at only 20 pounds. From an engineering point of view, that is barely adequate for a 7 to 8 lb load especially under the management of a curious eight-year-old who might be inclined to tug on the weight shell or something similar. So I am now shopping for some stronger string and will test it before using.
The weight shell was originally designed with thin walls to reduce print times below 20 hours on an older printer. I have at least a dozen weight shells without a single break, but I have never dropped one on a tile floor to fully test the indestructability. 😀 The newer faster printers have made me think about increasing the walls from 4 perimeters to 6.
The primary purpose of the internal ribs on the weight shell are to provide support for long bridges. They build up using a minimum amount of material to maximize the internal volume. Any added strength is a bonus.
PrusaSlicer integrates so well with Prusa printers that I have not switched to Orca Slicer. Scarf seams look like a huge improvement, and I am eagerly waiting for it to migrate into PrusaSlicer. Did you try using it on the gears? I am curious if a scarf seam on the gear teeth would stay smooth.