Moon Clock Weight Shell issue
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".
Wow, you sure are having some bad luck with the weight shell. I consider this to be the least "magical" portion of the entire clock. All it does is hang there.
The pulley does provide some separation to help guide the line as it is being wound. One thing to watch while winding is to make sure the line does not creep up the 45-degree slopes on the barrel. If it does creep up, it can collapse back to the center portion and the weight will quickly drop about 0.5". This could add some additional stress on the line. I can only recall one line breaking in 6 years of building clocks. It broke at the knot. There is probably a fishing line style knot that would be much stronger than a simple overhand knot.
I use Spectra Power Pro Microfilament Line. My first spool was 65lb test. My current spool is 80lb since it was the same price as 65lb. My quick strength test on a single strand broke at the knot with much more than 20lb. My guess is somewhere around 50lb of force. I use moss green but cannot imagine that it is any different than red except for the color.
The pulley should double the effective load carrying capacity. With the proper knot, a loop of 65lb line should be able to support a 130lb dead load. Any jerking motion would reduce this, but it should still be way above the expected 10lb load with some safety margin.
I looked up some fishing line break tests. The first random web site at Fishing Line Strength Test & Chart | Sport Fishing Mag showed about 40 different brands of 30lb line. All broke between 26.5lb and 66.8lb loads when wet. They estimated 8-12% increase when using dry line. They mention an improved Bristol knot. I will look this up to see if it helps.