I'm pretty new to 3D printing but long time clock maker. I am printing the SP3B clock and have read in the assembly notes that if I want to change the colors of the numbers on the dial I need to pause and reload a different filament at a specific point during the print. The notes say to change the filament at 15.35mm. Unfortunately I'm not aware what that means. I am using a Bambu labs printer (X2D) and Bambu slicer. Can you shed some light on my dilemma?
After my success with the SP2B I wanted to build another clock for a friend so decided to build the SP3B. I had trouble with the pallet striking the edge of some of the escape wheel teeth, but some filing took care of that over several filing sessions. I found that a weight of 5.5lbs was about the minimum that would keep it going with some of the teeth dragging along the pallet as I was working on that issue, but it ran great once I had them all 100% clear. After fixing the escape wheel issue I put together a simple pulley hanger so I could test the clock in 8 day mode before printing the weight shell, and have found to my surprise that it runs very reliably on the same 5.5lbs. The pendulum swings on average about 1” either side of dead bottom, so 2” swing total. …
It seems like you have everything running great. Not sure why the pendulum and pallet are interfering. Some designs have less clearance than others. I may take a look at it when I get a chance.
That clock has a 24.5" pendulum length measured from the pivot point to the center of mass. This likely gives around 28" to the pointer below the bob. 1" of swing works out to around 2 degrees, which should be enough. It doesn't hurt to add a bit more for additional margin. The frame can easily handle 10 pounds as long as the hanging procedure is followed to keep the top support beam from tilting downward.
Hi,
I've designed a new bob, so it can be filled with bb gun snot as well, be about 100g heavier to improve Q, but most of all to look beautiful. And it does! :) here is free scad file if someone else finds it useful
Thank you
Slava
Looks good. Thanks for sharing the design.
Some of my clocks have an updated bob with more open space to fill with BBs.
Last week I acquired SP16 from myminifactory, and promptly decided I wanted to put my own face on it: normal (arabic) numerals, but with the hour and minute markings round the outside edge as on the dials with the Roman numerals. Because.
Anyway, I messaged Steve about it, and he promptly and kindly uploaded the dial parts in .step format, making it far easier to hack my own dial onto it.
The deed was therefore done, I printed everything, and did a pendulum swing test; after 20 minutes it was still moving quite perceptibly, so I finished the build and started it up with 1.8kg of diving weights hanging directly off it. After an hour the pendulum amplitude had settled at about 4.8° each side, then it gradually increased overnight to about 5.5° after 12 hours. I assume this means it is being run in, and friction is still decreasing.…
Looks great. The dial has really nice proportions.
Mechanically, reducing the winding drum diameter should have the same effect as a block and tackle. Both provide longer runtimes if the weight is increased.
The winding drum on this clock is just slightly larger than the lower support post, so a smaller diameter would cause the string to rub. This would require a secondary pulley. Or similar to some of Brian Law's clocks, attach the far end of the cord to the wall off to the side. This change reduces the weight pulling down on the frame.
Steve
Thank you for the advice. It worked perfectly and much easier than I anticipated.