Hi Mark

Sorry to hear about your clock problem but working as a clock maker I may be able to suggest some possible causes. Many years ago I made one of these clocks with the idea of setting it up in the reception, along with other clocks, to give some indication of the progress of timekeeping over the ages. A point of interest I thought. The last one on display was a radio controlled clock by Junghans, these were new at the time and very expensive. The first was a sandglass, the Wilding clock represented the mediaeval period. I was surprised to find that this clock was somewhat problematic when first built. The foliot escapement had a somewhat spastic action, the clock would occasionally stop and it wouldn't run reliably on the indicated weight. When I started making it I wasn't totally happy about the escape wheel arrangement with the pallets butting against the wheel teeth and like you I tried rounding off the teeth edges but found it gave only a minor improvement. There is a clock with this type of escapement in the British Museum but this has pins in the escape wheels rather than teeth. John Wilding gives the option of this method in his drawings and so I made that. This gave an improvement. Should you decide to do this then the pins must be hardened and polished and be of equal length. What is completely axiomatic in clock making is that friction must be minimised through the train. Ideally the pivots should be hardened and polished, the wheels should be correctly depthed and the pins in the lantern pinions should be hardened and polished. You've already ensured that there is freedom in the pivot holes, another important factor. Ideally the pivots should not be oversize as this increases friction but I doubt that that is the cause of the problem.

Using non engraving brass for the frames will not be an issue in terms of performance. It doesn't cut so freely so ensure that none of the wheel teeth have burrs. Countersinking the pivot holes inside the frames in a new clock is not really normal but providing the arbor shoulders butt against the plate and not inside the countersunk it shouldn't be an issue. There should of course be oil sinks on the outside of the plates.

I feel that your problem is in the escapement rather than the train. Check that the semicircular pallet is exact to dimension. It should be hardened and polished. Make sure it's not coming loose on the staff. Check that the distance between the escape wheels is correct all around the circumference and that the pallet staff is dead central between the wheels. The tip of the staff should be hardened and polished, as should be the pad it sits on. I remember speaking to one clockmaker who'd fitted the tiny ball from a ballpoint pen on the bottom of the staff.

A problem I had with mine was of the escape arbor end float adjustment screw working loose. My own fault for not making the clamp tight enough. Again, ideally, the end of this screw should be hardened and polished. When correctly adjusted the wheels should run very freely with minimum end float.

I eventually converted my clock to chain drive as I had problems sourcing a suitable weight cord. As I don't personally like the endless chain arrangement it's just a single drop but of course I have to wind it more frequently. I've just been and weighed the weight; some 600gms, 1-1/4 pounds. Maybe you could try yours, as an experiment, with a single cord and smaller weight if you're worried about the frame flexing. With the weight I use my clock is accurate to about 20mins per day. About every two years it tends to stop but cleaning and lubricating fixes it. As it has no glass case it attracts dust which is not a good thing for any clock

I hope that at least one of these suggestions may be helpful. And as to my clocks through the ages display………….. I found the average layman to be totally uninterested.

Michael

Hi Mark, sorry to hear you're still having problems. I understand your frustration but I do feel that it may not be the best approach to start altering parts of the original design, ie weights and pallets. John Wilding is a prolific and highly respected designer and builder of clocks with many years of experience. Unlike many ME designers he does build everything he designs and as by doing the design is proven it should not require any modification other than possibly in the aesthetics of the design to satisfy a personal preference. As an example I replaced the cord drive with a chain drive. By increasing the weight excessively you will overdrive the escapement causing an excessive arc of rotation of the weight arm and it will be impossible to bring the clock to keep time even by increasing the size of the adjustment weights. Wilding would have carefully considered the geometry of the semi-circular pallet and I recall his claim that the geometry of the pallet on the model in the British Museum was not ideal and led to an incorrect action. In all clocks there needs to be an appropriate balance between the driving force and the escapement. The alarm pallets are designed for a strident bell action, not time keeping.

If I may suggest a course of action it would be this.

Totally dismantle the clock. Polish all the pivots to a mirror finish working down to very fine wet and dry paper, say 1500 grit. Clean out all the pivot holes with pegwood. Re-assemble all the wheels into the frames, one at a time, and check each for freedom of rotation and some end float. Initially no oil required. If the wheel is spun by hand it should take a time to gradually coast to a standstill. With all wheels in the clock, hang the weight but not on the spikes, rather over the spike wheel arbor so that no driving force is applied to the train. You can then re-check the wheels for freedom which will not be present if the weight is in fact distorting the frame to a detrimental extent.

The cycloidal tooth form used in clocks is, unlike the involute, somewhat intolerant of incorrect depthing and this could be an issue with the lantern pinion on the escape wheel. If you run the clock until it stops, then taking care not to disturb anything you could use a fine marker pen to indicate every wheel tooth and its engaging pinion leaf at the time of failure. Studying all the relevent teeth could possibly give you a clue.

You made the wheels with unleaded brass which may not be freecutting and there could be minute marks left across the teeth by the cutter into which one of the fine pinion pins could snag. Again, worth checking.

I don't personally subscribe to the view that the clock may need " running-in " and I've never seen it suggested before. By the time you get to the critical upper end of the train there is ( should be ) so little power that it's not going to wear anything in. Properly designed clocks can run for decades with very little wear providing they have some protection from dust. My own view remains that your problem lies with the escape wheel and pallet assembly.

I hope to see you soon report that you've made some good progress. Perseverence is the key and I await the outcome with interest.

Michael

Mark Just a thought but have you got the escape wheel teeth facing tghe right way I have built a couple of these useing just saws and files and all mine have run It is by no means a precision clock

Roy

That's excellent News, Mark.

I hope to learn from your experience.

MichaelG.

Yes Mark but just a tiny drop. Sharpen a matchstick, dip it in some clock oil and just touch it on the end of the pivot where it protrudes through to the outside of the plates.

Norman