JUF 49 Intermediate/Minute Wheel problem?

[MuseChaser]

I could really use some help from the deep brain trust here... I thought I was getting to the point that I could pretty easily find and rectify most problems on the torsion clocks I'm familiar with... 49s especially... but this one is driving nuts. Before the questions.. I have completely disassembled the movement, cleaned it carefully, oiled and exercised the mainspring, pegged all of the pivot holes, reassembled and judiciously placed a tiny drop of good oil at the pivot points, left out the anchor, and verified that the movement turns freely with only two clicks on the mainspring. HOWEVER... that is only true without the hands on it.

Here's a picture of the backplate, just to identify the clock for sure...



This is the first JUF/Schatz 49 I've come across (after renovating at least ten so far.. maybe more) that had this configuration on the front plate, with a keeper bracket over the hour wheel instead of a screw down through the center and the wheel placed to the right of the center wheel arbor; this one is above it vertically...



Here's another view... The arrow indicates where the concave pressure washer is right now.. more on that below...



On all the other 49s I've done, that concave pressure washer was placed directly on the center wheel shaft in front of the front plate prior to adding the cannon pinion, minute wheel, and hour wheel, and that's where it was in this clock, too. In Appendix 18, #109 Terwilliger shows that washer placed directly on top of the minute hand, behind the hand nut for Reiner and Herr clocks, so I thought I'd try that, too. Neither works..

Here's what's happening... the minute I tighten the hand nut enough to engage the minute hand/wheel at all (or the concave washer, if placed behind the hand nut)... even the VERY slightest amount.. the movement stops. The center arbor WAS bent a bit, but I've successfully straightened it and it shows no wobble now. The minute wheel (the one that rides on the cannon pinion.. I hope I have the terminology correct) seems "wavy".. not flat, with sort of warps around it, but to my eye it's pretty slight.

Here's an exploded pic... the two yellow arrows from the concave washer show the location where it was found on this clock and all of the other 49s I've experienced and where Terwilliger describes its location on Reiner and Herr movements (marked with the "?" in this pic). Also, an indication for the wheel that isn't perfectly flat.



Here's an edge closeup of that wheel...



...and one of the cannon pinion. I don't recall that slightly recessed band in the middle of the hollow shaft on other clocks I've renovated, but I could have missed it. Is it indicative of anything?



OK... that's all I've got. Ideas? Thanks!

 

[KurtinSA]

The clock was built in late 1949 or early 1950, before they started to date stamp the plates. That is a hold over from the earlier style of motion works. The last time I took one of these styles apart, the football shaped tension washer was between the cannon pinion and the front plate. I don't believe I had anything between the hand nut and the minute hand. I would be sure that the minute hand doesn't contact the hour pipe in anyway.

Kurt

 

[MuseChaser]

Thanks, Kurt. That's one of the first things I checked, but I'll definitely revisit it... right now.

Edit/update: I've managed to flatten the minute wheel and it looks good now. Made sure, under magnification, that the minute hand was not contacting the hour pipe.. and there's plenty of space there. Took apart the entire movement again, removed the center arbor and checked it make sure I got it as straight as I thought I had externally, and it looks good. Concave washer is back underneath the cannon pinion, on the center arbor shoulder by the frontplate. I DID notice that, when I placed the center arbor back in the front plate, it had a tendency to drag/catch a bit on the way in and out of the pivot hole. When I reassembled the movement and checked for end play, all of the arbors moved freely... except the center arbor. It would move easily when nudged, but would not "drop" back under gravity alone. I polished the contact point on the arbor a bit, and took a round file (only thing I have right now... no smooth or cutting broaches, but they're on the way) VERY gently twirled in reverse, then a hardened small screwdriver shaft as a "burnisher/smoother" went around the hole. Put the movement back together, and it's running now, but still very sensitive re/ how tight the hand nut is. I have it tightened down JUST until it secures the minute hand. It's run for about twenty minutes; I'm going to go shovel snow for an hour or two and see how it does. My gut tells me that, between the wavy minute wheel, the originally bent center arbor, and some little "catches" I can feel between the minute wheel and the cannon pinion... this thing took a pretty good shot on it's face at some time. Does that all make sense? Better to try swapping in a different center arbor rather than mucking about with the hole in the frontplate?

 

[Burkhard Rasch]

the football washer should sit on the shoulder of the center shaft, I had it once that the hole in the washer was worn out and the washer touched the plate.....Check that,too.
In theory there should be no movement between the center shaft and the cannon pinion when the clock is running,so tightness of the nut is regularly not the problem.
Check if the clock wants to run without the intermediate wheel,that can also cause a binding.
Good luck!
Burkhard

 

[MuseChaser]

Thanks again for the suggestions. I thought I had it licked...wound the mainspring 1.5x, made sure it was in beat, and rotated the pendulum the minimal amount to get it going. It picked up rotation in its own over the next hour or so until it got to about 300 degrees, and ran great...

Then, after shoveling and hacking at an ice dam on the roof for four hours, I came back inside to find it had stopped again. Grrrr.

One other weird piece of the puzzle...unlike my other 400-day clocks, even if I start with the hand nut on VERY lightly, the nut and minute hand get increasingly tight if I advance the minute hand to adjust to the correct time. So much so, in fact, that I have to loosen the hand nut almost every full rotation of the minute hand. Seems like that would indicate that the concave washer "clutch" interface is binding somehow, right?

 

[KurtinSA]

That's one of the "issues" with a hand nut. If you turn the minute hand counter clockwise, the hand nut loosens. When doing that clockwise, the hand nut can tighten because the hub of the minute hand is dragging on the inside surface of the hand nut and dragging it tighter and tighter.

Kurt