To bush or not to bush?

[rlynch106]

I started working on clocks just over a year ago. I still have problems determining if a pivot hole really needs to be bushed.
The attached videos show the pivot movement in a 1986 Howard Miller 341-020.

Would you guys and gals re-bush any of these pivot holes?

Thanks for any advise.

 

[roughbarked]

I'd bush all four shown in the videos.

 

[KurtinSA]

I'm no expert but movement in the smaller holes is going to have a bigger effect. I don't know what the guidelines would be but likely movement somewhere around 40-50% of the diameter of the pivot might be something to consider as needing to be bushed. Just a WAG!

Kurt

 

[Willie X]

I see 4 too. On a 37 year old Hermle, there will be several more.

Willie X

 

[Kevin W.]

I see 4 as said by others and i agree with what Willie said.

 

[rlynch106]

Thanks a lot for the feedback. I just wasn't sure if that was bad enough to bush. Yes there are others that have about that same amount of play.

 

[Richard.W]

I'm no expert either, but the one behind the gathering cam is problematic because it may effect the engagement with the rack. If the rack can't be lifted, then the clock will go on striking or may at least count incorrectly.

If you decide to replace that bush, then 1) document the cam's position and 2) pull or lift the cam straight off. Any unbalanced pressure on the cam will snap the arbor. A new 4th wheel arbor is $18 from Butterworth. Don't ask how I know all this detail.

 

[roughbarked]

I'm no expert either, but the one behind the gathering cam is problematic because it may effect the engagement with the rack. If the rack can't be lifted, then the clock will go on striking or may at least count incorrectly.

If you decide to replace that bush, then 1) document the cam's position and 2) pull or lift the cam straight off. Any unbalanced pressure on the cam will snap the arbor. A new 4th wheel arbor is $18 from Butterworth. Don't ask how I know all this detail.

It takes courage to admit mistakes.

 

[rlynch106]

I'm no expert either, but the one behind the gathering cam is problematic because it may effect the engagement with the rack. If the rack can't be lifted, then the clock will go on striking or may at least count incorrectly.

That is what this clock is doing. It often strikes an hour or two more than the hour, but usually only on the hours that the hour hand is moving up - hour 8, 9, 10.

If you decide to replace that bush, then 1) document the cam's position and 2) pull or lift the cam straight off. Any unbalanced pressure on the cam will snap the arbor. A new 4th wheel arbor is $18 from Butterworth. Don't ask how I know all this detail.

Still working on how to get the gathering pallet off. I have a small puller, but the bottom of it is too steep and I can't get under the pallet straight. I've heard others that have this kind of puller, and they ground some metal off the bottom of it. Guess I'll have to dig out the grinder. Or, I might have a pair of paint can openers laying around here somewhere.

 

[roughbarked]

Alternatively, you can separate the plates and remove as much as you can from the fornt plate, then with the aid of a carefully shaped and positioned anvil, the arbor may be tapped through with a light brass hammer.

 

[wow]

That is what this clock is doing. It often strikes an hour or two more than the hour, but usually only on the hours that the hour hand is moving up - hour 8, 9, 10.



Still working on how to get the gathering pallet off. I have a small puller, but the bottom of it is too steep and I can't get under the pallet straight. I've heard others that have this kind of puller, and they ground some metal off the bottom of it. Guess I'll have to dig out the grinder. Or, I might have a pair of paint can openers laying around here somewhere.

Two wide blade flat screwdrivers inserted on opposite sides and twisted simultaneously will often break it loose. Once it breaks you can pull it of with needle nosed pliers.

 

[Willie X]

When you get the GP off, check the shaft closely. Some shafts are scared, like struck with a tiny chisel. If so, that GP needs to go back in the same position.

Sometimes these dents/scars are so big that they will have to be carefully filed away. It may slide out through the old worn hole but bind badly when the hole is properly bushed.

Just a heads up ... the shafts can be completely smooth and round and some will have a stepped shaft. These won't give you much trouble.

Willie X

 

[roughbarked]

When you get the GP off, check the shaft closely. Some shafts are scared, like struck with a tiny chisel. If so, that GP needs to go back in the same position.

Sometimes these dents/scars are so big that they will have to be carefully filed away. It may slide out through the old worn hole but bind badly when the hole is properly bushed.

Just a heads up ... the shafts can be completely smooth and round and some will have a stepped shaft. These won't give you much trouble.

Willie X

Willie X is your man.

 

[roughbarked]

Two wide blade flat screwdrivers inserted on opposite sides and twisted simultaneously will often break it loose. Once it breaks you can pull it of with needle nosed pliers.

Speaking of needle nosed pliers, If you make a tube anvil with a slot to slide the shaft through and just the right length, you can slip it under the gathering pallet and if you have left just enough room for the round nose pliers, this will crack it off the tight point and it can then be removed with the fingers.

 

[Mike Phelan]

That is what this clock is doing. It often strikes an hour or two more than the hour, but usually only on the hours that the hour hand is moving up - hour 8, 9, 10.



Still working on how to get the gathering pallet off.

Heat up the GP with a small torch - that's what I do.
As the GP is brass and the arbor steel, that usually does it.

 

[rlynch106]

I got it off with little effort using the dual screwdriver method.

I don't see any scarring on the shaft, except for 3 scratches that were made when prying off the pallet.

Thanks again for all of the advise on this.