Herschede 1917 Grandfather Clock

[Jay Fortner]

Every bushing has three critical dimensions, height, outside diameter, and inside diameter (hole size). You will need a micrometer to get the plate thickness, and pivot thickness.From there, you could find the closest bushing match in Timesavers catalogue. You need to be able to make the hole in the plate a few thou smaller than the bushing, so you get a good tight press fit. And you need to be able to make the hole in the bushing a few thou larger than the pivot, so that it is not too tight, and has a few degrees of side tilt.

You beat me by one minute!

[124Spider]

Ok, I'll give it a whirl.

I haven't yet taken the mechanism apart, so precise measurements of the pivots isn't yet possible. The plates on my clock are 2.5mm thick; no bushings in the Timesavers catalog seems to be 2.5mm deep (2mm or 3mm, but no 2.5mm). Am I missing something, or do I have to choose too thick or too thin? The two bushings that clearly need to be redone both have pivots close to 2.5mm in diameter. Should I just buy a good variety pack of bushings, making sure that it included some of the larger ones like these? I have a house full of old clocks that periodically need fixing, so having a supply of bushings doesn't seem like a bad thing.

I gather that, by turning the winding arbor in the direction the spring pushes it, I see where the force on the pivot is wearing away at the plate; is this correct? Then I'll want to ream out the hole, keeping it centered properly, until it's round, and wide enough to engulf the off-center wear. Is this correct?

Is it ok to bang the bushings in with a hammer/anvil, or do I need some kind of fancy tool for the purpose?

Thanks much for your help!

[Jay Fortner]

You'll have to use the 3mm bushings,install from the backside(inside) and file flush and slightly countersink just enough to remove the square internal edge. Rotate the train OPPOSITE the direction of normal rotation to find the original centers. Yes you can drive the bushings in with a hammer and drift,keep them square with the plate and support the plate on a piece of hardwood. I prefer brass for my drift but steel will suffice. After installing and flushing the bushing you'll need to ream and smooth the bore to approximately 5% larger than the pivot. I recommend that you find an old plate or sheet of brass drill a hole to simulate a pivot hole then elongate that hole to simulate a worn hole and practice keeping your cutter from walking away from the center of original drilled hole. It's better to screw up scrap brass than your movement.

[124Spider]

Ok, I have acquired (I think) the tools I need to do this job. I've read up on bushing movements (and I have done it before, successfully).

So, I have some questions.

1. I want to practice on some plates I have around. I think I should insert the new bushing from the inside out; is that right?

2. How does one create the "sink" for the oil? Just by reaming the outside opening much more?

3. None of the raw bushings I could find is the right thickness (2.5mm). I am planning to use a 3mm bushing, as Jay recommended above. Is this correct?

4. Assuming I have to use a bushing that's thicker than the plate I'm working with, what do I do with the extra half millimeter? I don't see any way I can file that down without badly scratching the plate?

I'm sure I'll have other questions.

Thanks!

[Rob P.]

1. Yes, insert the new bushing from the inside of the plate.
2. The oil sink is created after filing the bushing flush with the plate. You can then take a large(r) drill bit/ball cutter and BY HAND turn the oil sink into the bushing. It doesn't take much.
3. The 3mm bushing is the one to use.
4. File the bushing flush with the plate. You can do it without scratching the plate if you're careful. If you want some protection, cover the plate with tape before filing. You won't get the bushing flush with the tape in place but you can get close.

I make my bushings from raw stock. I drill the pivot hole smaller than I need. When I insert them into the plate I "peen" them into place by using a rounded punch and putting the busing onto a rounded "anvil." I just put the pivot hole on the tip of the "anvil" and then tap with the rounded punch set into the other end of the pivot hole. This expands the bushing a bit and locks it into place. Then I file flush, finish ream the bushing, and smooth with the smoothing broach. By doing it this way I have never had a bushing spin and I can control the exact size of the pivot hole rather than relying on the mfg'd sizes only. If you continue to do this type of repair, you may want to consider this method.

Not that the KWM or Bergeon bushings aren't good, I just personally prefer doing it from scratch because there isn't ANY bushing size or pivot hole diameter I can't make.

[shutterbug]

If you know the bushing is too long, you can do the filing before you insert it. No damage to the plate that way. You can drill a little shallow hole the size of the bushing into a block of wood to help hold it while you file.

[David S]

I am with you SB. I always size them before insertion, either by filing of fine sandpaper with a tooth pick.
David

[Heritage-Clocks]

Well I have to cut in here. I won't file anything while it is in a plate, if it is going to leave tracks that I had been there. Now . With that said. Just put the bushing in from the inside and press out. Then take a drill .050 thou bigger than the bushing, and take it down close to the plate. Then take a chamfering tool (pizza cutter) and create an oil sink. If you do this right. You won't even be able to see that a bushing was put in. No hammers, no files, no solder, no marks. NO BS.......

H/C

[124Spider]

Thanks for all the help.

I've begun the process; the clock is dismantled, and I'm starting to clean the pieces. When I'm done cleaning, I'll re-assemble it, to carefully mark where new bushings are needed.

I'm sure I'll have other questions along the way.

[124Spider]

Update:

To review the bidding:

My clock had two problem I knew about when I put it in the hospital: The strike mechanism sometimes wouldn't go unless I gave it a little shove, and the pendulum wasn't swinging enough.

I've cleaned all parts; polished pivots; rebushed as necessary; examined everything; found some wheels which were being a bit pinched between the plates.

I've had the movement apart a number of times, tweaking and looking.

The good news: The strike mechanism works great.

The not-so-good news: The pendulum still doesn't swing hardly at all; probably less than half the swing it should have (and had for the first 20 years I owned the clock). When given a nice start, it slowly loses distance in swing over a half hour or so.

I've installed only the time mechanism, and still have the problem. Without the crutch installed, all wheels move very freely, move with the gentlest of force on the cable wheel, and keep moving for quite some time after I release pressure on the cable wheel. I cannot believe there is some sort of drag there that's not supposed to be there. The crutch seems to swing freely when installed.

There is no sign that the pendulum hits or scrapes against anything; there is a very slight gap where the crutch and pendulum engage, so it's not getting pinched there (no gap), or losing steam (too much gap).

The problem with the pendulum seemed to happen fairly rapidly. The clock went from keeping time fine, with lots of swing, to keeping time less fine, with less swing, to keeping horrible time with almost no swing, seemingly in two steps, over just a couple of weeks.

Any ideas would be gratefully considered.

Thanks.

[Richard T.]

Many of the things you mentioned have nothing to do with the "swing" (amplitude) of the pendulum. Check the depth of the verge, i.e. the relationship of the pallets to the escape wheel.

The first photo below shows a 5 tubular bell movement prior to cleaning. Look at the twelve o'clock position and you will see a screw that when loosened slightly allows the verge to be lowered. This is just an example of what I am talking about.

I found a picture of a Herschede in my file and if you notice the top center of the front plate there is an eccentric bushing that allows the verge to be lowered/raised. There is a second eccentric bushing on the other end of the verge arbor on the front of the clock.

If it is necessary to adjust the depth of the verge by turning the eccentric bushing, care should be used as some are very tight. A proper fitting screwdriver should be used and care taken not let it slip out of the slot and scratch or damage the clock plate.

Photos of that area of the clock would be helpful.

Best,

Richard T.

[Heritage-Clocks]

Check the wear on the pulleys. They may need to be bushed. These will rob you of power too.

H/C

[124Spider]

Thanks for the quick replies!

Mine is a simple, time-and-strike clock. There is no way to adjust the relationship of the verge (or its pallets) to the escape wheel's teeth.

There is no sign of damage to the verge, its pallets, or the escape wheel's teeth. There is no sign that the pulleys need to be rebushed.

Here's a photo of the escapement, while the clock is sort of operating.

[Jay Fortner]

Mark, Does the crutch have a clutch where it where the anchor arbor goes through its hub?,and is it tight?(or at least not really loose)

[124Spider]

I'm not sure what you're asking, but I think the answer is "No." There is no way to adjust the crutch or any part of it.

Here is a photo of the rear of the movement, showing the crutch. Applying a fair amount of force to the verge does not result in any twisting.