Orientation Affects Running

[bangster]

The clock is a Style 3 Big Ben alarm clock. I'm fitting it with a new hairspring. There are two phenomena I don't understand, and I'm hoping y'all can point me in some helpful direction.

Item 1: It only runs when the movement is lying on its lefthand (9 o'clock) side. In any other orientation, it immediately stops. In that orientation, it runs without interruption. Where's a plausible place to look for the cause of this?

Item 2: While it's running, the amount of rotation of the balance wheel doesn't stay constant. On some oscillations, it swings further than on others. Clock keeps running nevertheless. What might this mean? And how, if at all, does it relate to item 1?

I await suggestions, please. Right now I'm feeling ignorant.
Shaddap, Tex.

bangster

[shutterbug]

Most likely cause is bad cups or points on the balance. Also check to be sure the balance is neither too tight nor too loose. Check out the cups under magnification and you'll probably find the issue. Could also be binding in the hairspring where it passes through the adjustment assembly or oil on the spring but my guess is that you've already eliminated that :)

[leeinv66]

I agree with shutterbug, it sounds like binding of the EW pivots in their cups. Also, have you changed the mainspring bangster? A bad mainspring will exaggerate the problem.

Cheers
Peter

[clockpoor]

I have a clock suffering from a very similar problem. It is a little Seth lever alarm clock that I purchased a couple of weeks ago. It will run very well in any position other than the one for which it is designed, laying on it's face, laying on it's back, even upside down, but when turned right-side-up it slows and stops after just a few minutes.:?|

CP

[shutterbug]

There you go, CP. Same symptom, same fix :)

[Scottie-TX]

All here know this is DEFinitely not my deal - balance type escapements - but BONG, it reads like there's less resistance to wheel motion in the position it'll keep running. I've experience this as many others also have. Seems like mebbe the staff has a flatted pivot - no longer "VEE" shaped or the cup it rides in needs serviced or replaced.
Here comes ARJAY now, I believe. He's up on this krappola.

[Jeff C]

Would having one of these improperly balanced with the lever exhibit similar effects with regard to its orientation :?|

[Smudgy]

Bangster, the positional problem is related to the escapement, probably the balance pivots or cups as noted in earlier posts. A less likely cause would be loose pallet fork pivots, but my guess would be the balance pivots. The fact that it only runs with the 9:00 position down may help as that lets you know what position the escapement is in when it has the least resistance, but it is unlikely to since it only works in one position (as opposed to not working in only one position). But you may want to check the relationship of the parts when in that position to see if you can tell why (like the hairspring touches the balance arm unless it's in that position or the pallet fork doesn't engage properly in other positions).

The changing rotation of the balance would be a result of varying power reaching the escapement. Without seeing for myself, and at a guess, I would say that you had a bent pivot in the train, but it could also be due to eccentric wheel, damaged teeth, dirt, or a stick mainspring. You should be able to track down the location by the frequency of the drop-off. If it is the mainspring it will probably end up random, but may make a sound when the spring releases.

Jeff, the balance being out of poise will cause changes in timing related to the position, but shouldn't cause the clock to quit running unless the movement has other more serious problems.

[shutterbug]

Would having one of these improperly balanced with the lever exhibit similar effects with regard to its orientation :?|

I have seen, but only once, that the balance was turned 360 degrees when replacing it and the spring had a small coil riding on the top that was hard to spot but caused the same symptoms. I doubt that this has occurred in your case, but it's worth looking at. You could simply unpin it and re-pin in the proper orientation if that were the case.

[PaulFaf]

Hi Bang.

Item 1: It only runs when the movement is lying on its lefthand (9 o'clock) side. In any other orientation, it immediately stops. In that orientation, it runs without interruption. Where's a plausible place to look for the cause of this?

Item 2: While it's running, the amount of rotation of the balance wheel doesn't stay constant. On some oscillations, it swings further than on others. Clock keeps running nevertheless. What might this mean? And how, if at all, does it relate to item 1?

This may be of use to your problems.

Fork assy is a 2 part peice.

The fork and pins are mounted on a hollow tube. The tube has a peice of pivot wire running thru it from plate to plate. This came up before on the board and a few guys got real extravagant with recomendations. Mine is simple.

Runs a 9:oo correct. Put it at 9:00. Pinch the fork tube in the middle with needlenose pliers. This will crush the tube and give a firm hold on the pivot wire.

Worked for me. Hope this helps.

[bangster]

Thanks for all the suggestions, everbody. I'll try 'em all. Stay tuned for a later progress report.

bangster

[bangster]

Removed balance. Removed hairspring. Filed & polished both points. Put it all back together. It's been running like a charm, right side up, for several hours.

I think that Dunnit.

Thanks again,
bangster

[Jeff C]

I've been wondering. What is the proper amount of rotation for these balance wheels? Is there a minimum/maximum acceptable amount of rotation?

[Smudgy]

Ideally rotation would be up around 1.5 turns, but I don't know if this low quality type movement have that much when new. If rotation drops below about 1 full turn you will get problems with isochronism as the mainspring winds down, as well as positional errors (which aren't really a concern on this type of clock), and it would be a sign that there is a problem that needs to be addressed.

[Mike Phelan]

Needs deleting!

[Mike Phelan]

I agree with shutterbug, it sounds like binding of the EW pivots in their cups. Also, have you changed the mainspring bangster? A bad mainspring will exaggerate the problem.

Cheers
Peter

It's the balance staff pivots that the cups are for, not the EW, but they are almost certainly the problem! It might be possible to turn them so the wear is at the top.

[bangster]

FWIW, I didn't spot any wear in the cups, but staff ends were grooved and rough looking. As long as it keeps running, I'll call it good. It's my clock, and not a very important one. Already contains bodges that I don't feel like trying to fix, as long as they work.

bangster

[Mike Phelan]

Oh - maybe someone else has been there first; the staff pivots usually wear right on the points and end up with the same taper as the cups, causing more friction.

[RJSoftware]

Bang. How did you file the balance wheel points/pivots? You gotta lathe or did this by hand somehow...?

RJ

[bangster]

Bang. How did you file the balance wheel points/pivots? You gotta lathe or did this by hand somehow...?

RJ

With a lathe. But alas! I been over-optimistic. Same problem has recurred. Back to the ol' drawing board.

Couldn't get along without my Peerless Marshall lathe.

bangster

[Mike Phelan]

Bang. How did you file the balance wheel points/pivots? You gotta lathe or did this by hand somehow...?

RJ

RJ - they are, or should be, glass hard, so the answer to your question is "never".
They can be dressed with an Arkansas or similar stone. You don't need a lathe - a drill will do.

[bangster]

Hmm. I seemed to do OK with a pivot file, followed by a fine abrasive lapstick. Made the grooves go away. At least it looks like they did.

bangster

[RJSoftware]

For what it's worth.

One thing I found was that prongs on fork lever get bent just a tad somehow.

I had the bad habbit of forcing the pin past the lever prong when it was on the wrong side. Ooops or maybe duuuhhh....

It causes the balance wheel pin a little extra bumping when it contacts fork lever prong. Since the lever fork was no longer square.

The position of the clock effects the way the lever interacts. Making sure the lever fork is square and prongs are properly spread had helped on one of my clocks.

RJ

[bangster]

Okay, a ray of smarts may have struck me. I said there were "bodges". At some point, a repairperson apparently tried to fix worn scapewheel pivot holes by piling gobs of solder onto the plates, to hold the pivots in place. That's Fact #1.

Fact #2: I finally put a mark on the scapewheel, so I can follow it around, and watched how it relates to the aforementioned changes of oscillation in the balance. They correlate. At a certain sector of the EW, the balance reduces its angle of oscillation, then increases it when that sector has passed. Enough correlation to infer a causal relationship somewhere.

Tell me what you think of this idea: The bodge is causing one pivot of the EW to bind slightly in its travels. This reduces the impulse to the balance, and the clock eventually stops. With different orientations of the movement, the EW bind is lessened (but not eliminated) and the clocks keeps running, but erratically.

If that sounds right to everbody, then my next moves will be: remove the solder gobs. See if I can figure out a better way that doesn't involve a ton of work, and try it. If not, consign this alarm clock movement to the Parts Bin, and move on to better things.

I regard all of this time spent as time learning...but my patience has limits.

bangster

[shutterbug]

I'd definitely remove the solder and rebush! If nothing else, it will eliminate one of the "probables" from the equation.