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Schlenker und Posner Bandstand Issue

KurtinSA

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Nov 24, 2014
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I decided the overhaul my SuP Bandstand clock. I posted about it in the following link. I think I've settled on plate 1624 although there are differences. Based upon work reported by John Hubby, there are a number of plates in the repair guide that are misidentified. And from John's dating, this clock is likely from 1935.


It tends to run 6 months at a time, so I thought I'd try overhauling it and see if I could improve on that. As I took it apart, I began to think that I might be the first one inside. Then when I was polishing the pivots, I ran across the forward pivot surface on the center arbor. This is the larger diameter surface and it fits through the front plate. This is the best picture I could take. I've tried to upload the original image and hopefully the defects can be seen.

Basically, the pivot surface is not round. It's been filed in many different places. I can't imagine how that got there...certainly not from the factory! There's not much I can do but press on. I don't have any replacements...SuP is a unique manufacturer and there are no easy replacement parts. The proper fix as I see it is to machine the pivot surface down to a pure cylinder and then bush the front plate hole appropriately. Both of those are beyond my capabilities. It did run for 6 months as is, so that may be all I'll get out of it. I did the "click test" without the anchor and got good movement out of the escape wheel. However, under more main spring load, the uneven surface on the pivot face is going to run roughly in the hole. Oh well, that's all I got!

Kurt

20210916_144135.jpg
 

Wayne A

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Sep 24, 2019
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Almost looks like it was chucked up in a drill a few times to mark it like that. Some of the surface appears to be fine, does the marked sections actually contact the plate?
For sure would take a bit of machining to fix that.

Wayne
 

KurtinSA

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Nov 24, 2014
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Wayne -

I'm not sure how much of the perimeter touches the inside of the hole. I'd have to use some marking dyes to see where the contact is. I have the movement assembled ready to hang on my test stand...I can't put it back in the case and really work on the beat, etc. I just tried to move the center arbor that sticks out in front of the plate and it doesn't move a lot although I can feel it...never did that before with a clock so I don't know how much movement one would expect. As I said, it worked with the "click-test" and seems to be able to run for 6 months...that may be the best I can expect.

Kurt
 

KurtinSA

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Nov 24, 2014
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Well, that's pretty disappointing. :banghead: I continued through the clock and got into the bench testing phase. First I got good performance from the clock without motion works and hands...around 270 degrees of rotation and 40-45 degrees of over swing. I put the motion works and hands on...had some issues as in the clock wouldn't run. So, I stepped through trying just the cannon pinion, then adding the hour pipe, finally adding the intermediate wheel. Clock didn't falter and ran with the same 270 and 45 degrees. Ran like that for several hours. I usually try and go for 12/24 hours but decided it looked strong enough. Assembled and final oiled. It's not as easy as just slipping the dome over it...it has to be placed back into the bandstand case and it is held with four nuts from the top.

Woke up this morning only to find the clock had stopped after about 3-1/2 hours. Not good. On "regular" clocks you can easily peer into the movement and assess what might be happening...find something is not turning. But with the enclosure of the bandstand, anything that is done to remove it will "change" where it's at now and make diagnosing more difficult.

Great. I can take a clock that was happily working over the past 3-4 years by winding it every 5-6 months and after my skillful hands, have a door stop of a clock. Again pretty disappointing. :(

Kurt

Update...well I can see that the escape wheel isn't turning...probably suggests the motion works...or not!
 
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Wayne A

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Sep 24, 2019
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Reminds me of a carriage clock or two, can't see or get at it when assembled..arh! Maybe during final assembly the plates are getting flexed creating a bind?

Wayne
 

KurtinSA

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Nov 24, 2014
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Final assembly was just putting the dial on, so don't think that was it. I think it has something to do with the hand nut and tension on the cannon pinion. I'm away from the clock at the moment and it will be a while before I can check it out.

Kurt
 

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