Debug Hints

Hi Chris,

It seems like there are two issues here. SP4 received the same upgrade as SP5 to improve reliably considerably. You can download the updated SP4B design as long as you can still log into MyMiniFactory using the same account used to purchase SP4. Unfortunately, I believe it is mostly a complete rebuild. The new gears have to be completely replaced. The new gears and winding key require a new frame. So the entire clock needs to be reprinted. The weight shell and pendulum might be the only re-used parts.

Getting SP4 running again often requires finding what may have changed regarding friction. Sometimes the bearings need to be cleaned. Also check for end shake on the central arbor and escapement arbor. A very tiny bit of side thrust can stall the escapement. It may help to add grease to the pinion teeth. Only a tiny bit is needed and it will work its way through the main gear teeth. PLA seems to be resistant to most greases and solvents. The only other advice is to do the debug checklist that you have already completed. Double check that all gears spin on their arbors and all arbors spin in the frame. This is especially true for the gear 3 arbor since gear 3 is attached to the arbor (or at least it is in the SP4B implementation).

Since you also have the new SP5B, maybe it would be best to focus on debugging that clock. If the pendulum swings for 10-12 minutes, why does the clock stop running in less than 2 minutes? Is the escapement rotating freely? Or is it getting in the way of the pallet and slowing down the pendulum? Move the pendulum back and forth manually. The escapement should start spinning immediately when the pallet clears the escapement teeth. Any lag in the escapement starting to spin will prevent energy from being transferred to the pendulum. Check for end shake on the central arbor, the gear 3 arbor, and the escapement between gear 3 and the shaft collar.

The easy build clocks do not suffer from frame sag like the other vertical oriented clocks. You probably don't need to worry about it as long as the frame was printed with 3-4 walls for strength.

Steve

Good point. Thanks for pointing it out.

I usually use a piece of painter's tape to hold the lever in the open position when travelling. Removing the pin is a much more secure way of disarming the rewind mechanism.

Thanks Steve, will check out the new design. So in the end I was worried about run time for no reason 😀

The video is very helpful. The entire gear train normally rotates with around 6-8 lbs on the weight shell, which is only 3-4 lbs on each end of the string. The pulley has a small diameter and you are pulling at the larger diameter teeth. It should take significantly less than 1 lb of force on the teeth to get the escapement to rotate. Parts appear to be flexing in the video, so it is likely that you are applying more than 1 lb of force.

My guess is that there is extra friction in the gears near the escapement. Torque reduces and speeds increase closer to the escapement. Friction near the escapement becomes exponentially worse than friction near the weight shell. The escapement is barely moving around 15 seconds in the video where it looks like force is being applied to gear 8.

You could try debugging the gear train without the pallet. Hang a 4 lb weight directly on the string. The gears should start spinning quickly. If you stop the escapement, it should start spinning quickly. Also, go through the friction related debug steps. Test that all gears spin easily on the arbors. Check all gears for end shake. The gear 4 stack in the center of the clock is a common area for a lack of end shake.

The good news is that your clock is incredibly close to being fully functional. Once you find the friction source, it should start working great. I like the reverse colors on the globe.