How do you instinctively know if a pivot has too much sideshake or endshake?

[GregG]

A lot of the advice around the forum when diagnosing low amplitude is to check the sideshake and endshake and re-bush or jewel as necessary.  I learned from the previous topic I made that sideshake should be around 0.02mm for the gear train.  And while I know this number, I do not know how that correlates to the real world.  I obviously can't stick a caliper or micrometer into the pivot hole, so that means I'll have to know what it is by feel and by appearance, but this I am not sure of.  Can someone give some insight on how to do this?

Another practical question is that if a pivot hole is worn to the point where its oblong and needs to be staked and broached, where in the hole do you do that? Even if you manage to close the hole up enough, you'd have to ream/broach exactly over the center of the original hole, not the center of the new smaller hole, since the center of the new hole is still not where the original center was.  Kind of hard to describe this without pictures, so let me know if you need clarification.

[Marc]

30 minutes ago, GregG said:

Can someone give some insight on how to do this?

There is a rule of thumb for this which is that with everything dismantled, stand the wheel in question upright in it's pivot hole and observe how far it is able to lean from the vertical. Ideally you are looking for about 5 degrees of lean.

Now although you can't put a protractor into the system to measure this, you can draw two lines on a piece of paper that intersect at 5 degrees to give yourself a bench mark with which to compare. Believe it or not the human eye is usually pretty good at comparing angles.

[Nucejoe]

Its like you say a feel. This guy shows the end shake on an escape wheel. I call this amount excessive. The reason is;    you want pallets interface level with escape teeth/ wheel and the shown amount of end shake when combined/ added to end shake on fork arbour might not give you the level interface you desire. 

For side shake, I grab the arbour in tweezers and feel the side shake. You will get the " feel"  by experience, you can also observe the pivot's shake in the hole under high magnification. 

 

[GregG]

11 minutes ago, Nucejoe said:

Its like you say a feel. This guy shows the end shake on an escape wheel. I call this amount excessive. The reason is;    you want pallets interface level with escape teeth/ wheel and the shown amount of end shake when combined/ added to end shake on fork arbour might not give you the level interface you desire. 

For side shake, I grab the arbour in tweezers and feel the side shake. You will get the " feel"  by experience, you can also observe the pivot's shake in the hole under high magnification. 

 

Thanks joe, but how do I correlate a feel with too much or too little sideshake?  If I have one pivot that shakes x amount, and another pivot that shakes a tiny bit more, how do I know if the first is good and second is bad, or if both are good, or if both are bad?

With endshake, I can imagine it would be easier to determine.  If the teeth of one gear interact with the teeth of another gear, you would not want the endshakes to be so loose as to possible cause those two to loose their meshing, correct?  Or in the case of the video, ideally the escape teeth and the pallet jewels would be at the same level.  But if the endshakes are too loose, theoretically the jewels might just barely be catching on the escape teeth.

Edited June 24, 2022 by GregG

[Nucejoe]

I try to minimize the shakes as long as I get an effortless  transfer of power to the adjacent part.