Hi, steve! It's John again! I was almost done printing the small pendulum clock from myminifactory and was having some problems with the fitting of the gears on the arbors. To clarify, I am having issues with gear7-24 and gear7-48, the rachet. My 2.15" 1/8" stainless steel tube is not fitting inside the gears so I was planning on slightly increasing the width of the hole but was wondering if the gears, or a single gear, are supposed to fit tight or be loose on the tube. If it is supposed to be loose or tight, does that apply to other gears as well?
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To see this working, head to your live site.
Lead is getting harder to find because of the toxic properties.
My favorite material has become copper coated steel BBs. The weight shell only needs to be around 50% larger than a lead filled shell. Here is the cheapest I can find.
Steel slingshot ammo might have very similar density.
Hi Steve! Thanks for your suggestions. I went ahead and tested each of the gears individually in the frame and then all together with the pallet removed and I did not notice any binding or friction. The only solution I am seeing is printing a quarter or half extension and increasing the weight to 7 or more lbs, as it is currently at 6.3lbs. I am not understanding what you mean for the weight shell directly on the cord. Do you want me to remove the pulley and attach the loop of the fishing wire to the pulley pin? Should I try that first?
Hi Steve sorry to bother you again but I found another problem. Occasionally, the escapement stops after slowing down for 5 seconds and I was wondering if you knew where the most likely spot of trouble would be? After I push on the ratchet or the weight it begins again but that cant happen when I am not present.
3mm rod (0.118") is very close to the 1/8" (0.125") inner diameter of the bearing. It shouldn't hurt for the rod to roll around on the inside of the bearing. You could add a wrap or two of scotch tape around the rod to see if it makes any difference.
Thanks steve! The looseness I am referring to is the fit of the bearings on the 3mm rod. It is quite loose and was wondering if the interior of the bearing is supposed to be tight on the rod. The fit of the bearings in the frame is quite tight so i might file the holes out a bit to make it a bit looser but I was wondering about the fit of the interior on the rod.
The good news is that you have narrowed down where you should be focusing your debug effort. The clock is probably very close to being fully functional.
If the bearings are tight in the holes, they can often be tilted sideways and add lots of extra friction. A loose fit seems to be best. Really loose with large gaps might indicate the wrong size parts.
I use cheap bearings that typically cost around US$5 or less for a pack of 10. Try different bearings if you have others. Sometimes 1 or 2 bearings per pack are slightly gritty.
Break down each problem to be as small as possible.
Test each gear pair to see if they rotate smoothly or if there is any binding. Then install the entire gear train without the pallet. The escapement easily should spin with less than 1 pound on the string.
Take out the escapement and test the pendulum free swing time. If it takes less than 5 minutes for the amplitude to degrade from 8 degrees to less than 1 degree, then look for friction in the bearings or the arbor passing through the frame.
Also, double check that the pendulum and pallet are rigidly attached. The clock can lose a lot of energy if one of the shaft collars is loose. A bit of glue to hold the shaft collar firm might help.
Good luck with the debug.
Hi steve! I successfully finished the clo