SP4B Help
Hi Steve, I'm in the process of building the SP4B but am having some on going issues. I printed this as a 17 day clock, get about 8.5 min on the pendulum free swing test, and used about 7.5 lb of weight. All of my gears spin freely on the arbors and I'm using bearings everywhere I can which I cleaned out more than once with alcohol. When I first setup the clock it ran great but would stop about once per day randomly, it would re-start right away. Each day it ran less and less until it wouldn't run at all after a re-start During the trouble shooting for that I re-cleaned my bearings ( I used WD40 Dry Lube which seemed to gum up after a few days) but that did not solve the issue. I removed the escapement and let the weight free fall and in doing so I found 2 gears which were warped so I re-printed those (Gear 1 and 3 if I remember right). I fully re-assembled everything repeating all the pre-fitment checks and the clock still will not run. As another test I increased the drive weight to 9lbs, then 10.25lbs. Most recently, the clock will start and tik in beat but very quickly something is off and the escapement gear hits the pallet, bounces backwards, then hits the pallet again (so a double hit each rotation) This rapidly decreases the amplitude until it stops entirely. The escapement gear also occasionally just stops in between ticks and I can very easily rotate it by hand with no resistance but the weight cannot rotate it on its own. Do you have any thoughts where else I can troubleshoot this problem? Thanks in advanced!
If the escapement stops spinning between ticks, the clock will likely stop running. The escapement interfering with the pallet also sounds like the escapement is not spinning fast enough. A deadbeat escapement has a very short duration to impart energy to the pallet and pendulum. The escapement must start rotating instantly.
Things to check are listed in the debug section of the manual. The gears spin easily on the arbors. Make sure they also spin easily after mounting in the frame. There needs to be a small amount of end shake or side play. This is especially true for the central arbor and the escapement arbor in this clock.
It is also possible that some filament types are stickier than others. They can usually still get them to work by lubricating the pinion teeth with dry lube or even lithium grease. Only a tiny bit is needed. I usually apply grease using a toothpick and wipe most of it off so only a thin layer remains.
17 day mode with 7.5lbs is fairly aggressive for this clock. Reducing to a shorter duration might be needed as a last resort. This will give more energy to help the escapement spin faster.