Sessions mechanism does not have enough power in time train

[bsg]

Hi,

I have a mechanism made by Sessions. I took it apart, cleaned it, and put it back together. Gong train seems to be fine, but the time train seems not to have enough power. When pendulum stops, if I move it, the counting(terminology?) wheel does not seem to move. Then I wiggle things, and it runs for a little bit again.

One thing I am sure of is that great wheel(terminology?) on that train is loose against its arbor. I did find this thread on how to fix that:

Great Wheel Loose on Arbor: Best Way to Tighten?

I have a main wheel that is loose on it's arbor. Can I use a hollow punch to reseat it? Thanks in advance, Doug

mb.nawcc.org

but my question is: can a loose great wheel rob the power, since if I understand this correctly, it is moved by spring through a clicker, and clicker is still there, or do I have other big problems needing bushings?

Thanks.

 

[Willie X]

Sessions clocks have a lot of common problems. The two main problems are: the 'clicks' often fail and the top 4 pivot holes in the time train wear out.

The pendulum swing will be about
1 1/8 to 1 1/4" when all is well.

Willie X

 

[bsg]

Pictures, just in case.

So, do I need to install bushings?

 

[Willie X]

It's hard to say from a photo but the front E-wheel pivot has been punched and the next pivot hole down is badly worn. Worn pivots are often badly scored and rough. The act of punching a hole often damages or bends the pivot. None of this can be seen until the clock is taken apart.

You may be able to spot a bent pivot with the 'fast run test'. This is done by removing the pallet arbor, after letting both springs down, then wind the time side back up a few turns. Bent pivots will wobble when viewed on axis.

Rough pivots can often be detected by sliding the arbors back and forth while applying side pressure. If good the arbor's/pivots will slide smoothly from front to back. This also checks the end play. If it won't rattle it won't run.

Willie X

 

[Mike Phelan]

Pictures, just in case.

So, do I need to install bushings?

Even seeing the pivots in your pics, definitely!

 

[R. Croswell]

Looks like bushings have been installed at the 4th time wheel and 3rd strike wheel, and both of these bushings are badly worn. Previous bushing work is always suspect. I would guess that these pivots were never properly burnished or polished and put back rough which eat out the bushings. This movement needs to come apart for cleaning and careful inspection. There are probably other issues as well. Cleaning includes cleaning and lubricating the mainsprings.

RC

 

[bsg]

So, how do I fix old bushings? If I drill new hole for a bushing inside the old one, would it hold? Or do I have to remove the old one completely?

If removing, does this mean I have to figure out what the old system, KWM or burgeon was used, since burgeon bushings are bigger, and it looks like those are 3 mm or more OD with 1.5 mm bore, i.e. burgeon.

 

[Willie X]

If you are lucky the bushing can simply be replaced with a new one but the pinion will need to be checked closely and refinished as necessary. Then the hole in your new bushing will have to be carefully broached to fit the refinished pivot. Usually, several pivots will need this treatment. The pivots that are good will need a quick polish and the hole pegged out. Willie X

 

[bsg]

I got all that, thanks. Except there is a little problem I have, which I bet is not uncommon here.

I am a beginner, I only have 7 clocks, with 6 of them I was able to get going by playing a bad car mechanic and just buying and adjusting missing parts, like chimes, weights, pendulums, mounts and so on. I know how to take them apart, clean them, and even put them back together without extra parts left, and they actually run. I know how to oil them, including mainsprings. I can put new clicks on, replace bellows. I can completely redo the case if needed, but that's woodworking.

However, I have not done any bushing work so far. So I am trying to come up with the essential set of tools to do it by hand. I red the following article:

Bushing Using Hand Tools

BUSHING USING NOTHING BUT HAND TOOLS

mb.nawcc.org

and other things here and there.

I know you Willie X advocate for KWM system, since they are smaller. Who am I to disagree.

Problem 1. I may need to install new bushings. My pivots are 1.5 mm, plate thickness also 1.5. So, I gather I need:

0. Small diamond file.
1. 2.6 mm cutting broach
2. 2.6 mm smoothing broach
3. Pin vise.
4. KWM reamer #3, handle, and 5 mm cutter.
5. Bushings.

Questions for problem 1:
1. Can I go all the way from current 1.5 mm hole to 2.6 mm by just using one 2.6 mm cutting broach, or do I need intermediate ones. I guess the question also would be if the broach end cuts anything. Sorry, never saw or used broach before.
2. Should I buy assortment of bushings, like L38-L89, or do I just get the one with smallest bore and then enlarge it with additional broaches if needed?

Problem 2. I have existing bushings, which look like burgeon style judging by bigger diameter. So should I get:

0. 3.45 mm cutting and smoothing broach.
1. 3.5 mm burgeon reamer fitting KWM handle.
2. Burgeon bushings.

Questions for problem 2:
1. Is this a good way, or should I just forget about KWM and go with burgeon?

Thanks.

 

[Willie X]

I have published a minimum list of tools for bushing work several times. Maybe you can find it, or someone will find it for you. Willie X

 

[bsg]

OK, thanks.

 

[bsg]

My bad. To many questions per single post. Still, not to bother Grands too much, but:

1. Can I go all the way from current 1.5 mm hole to 2.6 mm by just using one 2.6 mm cutting broach, or do I need intermediate ones. I guess the question also would be if the broach end cuts anything. Sorry, never saw or used broach before.

 

[bsg]

Actually, don't worry about it. I placed order for parts already. I'll figure it out.

 

[R. Croswell]

........can a loose great wheel rob the power, since if I understand this correctly, it is moved by spring through a clicker, and clicker is still there, or do I have other big problems needing bushings?

As long as the click is engaged to the click wheel the great wheel will receive power from the mainspring. If the great wheel is loose it may tilt and not align with the pinion, or rub something, so yes, that is a possible cause for power lose, but I suspect that you have "other big problems". The big danger with a loose main wheel is that the click may slip off of the click wheel causing the spring to suddenly release.

1. Can I go all the way from current 1.5 mm hole to 2.6 mm by just using one 2.6 mm cutting broach, or do I need intermediate ones.....
2. Should I buy assortment of bushings, like L38-L89, or do I just get the one with smallest bore and then enlarge it with additional broaches if needed?

Problem 2. I have existing bushings, which look like burgeon style judging by bigger diameter. So should I get:

0. 3.45 mm cutting and smoothing broach.
1. 3.5 mm burgeon reamer fitting KWM handle.
2. Burgeon bushings.

1. Is this a good way, or should I just forget about KWM and go with burgeon?

There are a number of ways that have been used to install bushings, unfortunately some yield less than perfect outcomes. Methods that may get your old Sessions ticking may not work at all on a fine French clock. If I had just one piece of advice for beginners, it would be, remember that just because you got it ticking does not mean that you have fixed it. This Sessions clock probably will need about 8 to 14 bushings, although it may manage to tick for a while with less. Many a clock has been destroyed, or made difficult for someone else to fix correctly, by improper bushing installations. Regardless of what type of bushing you use and how you retain it in the plate, the hole in the bushing must be dead center over where the original hole was, and the hole must be perpendicular (straight) with the plate. You will not get good results by just eyeballing, guessing, or assuming that things are centered and straight - it requires deliberate action.

* In regard to broaching and broches, always assemble both plates before broaching a bushing. Start with the smallest broach that will extend into the hole on the opposite plate as a guide. If you need to open the hole a lot, progress to the next size broach. Use broaches is necessary to open the hole in the bushing. Best not to use broaches to open the hole in the plate for the bushing.

* Regarding reamers, these are intended to be held is a bushing machine, or perhaps a drill press or mill. It is impossible to hold a reamer straight by hand, so if you ream to the full diameter of the reamer, the hole will likely be oversize and may also be less than straight. Obviously you buy the reamers for the bushing sizes you plan to use.

* Regarding KWM vs Bergeon bushings, if there are already Bergeon bushings to be replaced, just use new Bergeon bushings. If you find an off-center bushing, A Bergeon bushing will make it easier to shift the hole to center. Otherwise, there is no compelling reason to use one over the other, or for not using both as may be appropriate.

RC

 

[Willie X]

Normally you would use a #3 KWM 'D' cutter to make a 2.7 mm hole for your bushings, Merritt's P-1296.2.68 cutter and P-1609 handle is good. Drill press adaptor is P-1606. Stay with KWM sizes with Bergeon mount/shank.

For broaches the full 12 piece set P-455 is good. The 6 piece set used to be smaller, but now the broaches are on the big side.

You can usually change or add to an order if you call within about 24 hours.

This movement is not especially easy to work on. It would probably be better to start out on an easier movement.

Willie X

 

[bsg]

Thanks to you all for very useful information!

Not to sound completely obnoxious, but in this article here

https://mb.nawcc.org/wiki/Encyclopedia-Subjects/Clock-Repair/Bushing-Using-Hand-Tools

the author describes how to do the bushings with just hand tools. Also I assume they sell the handle for reamers for a reason. And those reamers are not general purpose even though they can be, they are designed to be used for bushings.

What do you think about it? Is this back to "remember that just because you got it ticking does not mean that you have fixed it", or is it a legitimate, albeit hard, technique?

 

[Willie X]

With practice you can get pretty good. However, if this clock is a 'keeper', it would be best to put it on the shelf for later, as already suggested. Willie X

 

[R. Croswell]

Thanks to you all for very useful information!

Not to sound completely obnoxious, but in this article here

https://mb.nawcc.org/wiki/Encyclopedia-Subjects/Clock-Repair/Bushing-Using-Hand-Tools

the author describes how to do the bushings with just hand tools. Also I assume they sell the handle for reamers for a reason. And those reamers are not general purpose even though they can be, they are designed to be used for bushings.

What do you think about it? Is this back to "remember that just because you got it ticking does not mean that you have fixed it", or is it a legitimate, albeit hard, technique?

Not likely that you will find true center using that method. Also, bushings you buy are designed to be held in place in a reamed, (not broached) hole with parallel sides by skin friction alone. It should not be necessary to expand a bushing by pounding a ball bearing into the end, which only expands the end and distorts the bushing. If you try this method, use a bushing with a smaller ID so you can broach the hole to a more or less uniform size after buggering up the ends of the bushing to keep it in place. So will it work to get it ticking? If this clock has its original 0.018" thick mainspring it is pretty overpowered to begin with. If you have just one or two severely worn pivot holes that are so bad that the clock won't run, using the described method can make enough improvement to get the clock ticking again. Any misalignment from center will cause increased friction between the gear and pinion. The effect is cumulative over the total number of bushings installed. When you get to the point where the additional friction requires more power than the heavy mainspring can provide, you will have very little or no overswing or recoil and the clock will be unstable, very sensitive to being level, prone to stopping, and may stop short of 8-days (in good shape, this clock can typically run 10 or 12 days on a full wind. With care and practice and a lot of extra work (compaired to doing it the "right way") you may achieve results that you will be satisfied with. In my opinion, this ain't the way to do it.

This comment would not be complete if I didn't say that even with a drill press, bushing machine, or mill, you can still screw up a bushing job. It takes experience and the right tools and an understanding of the limitations of the tools being used.

RC

 

[bsg]

Thanks a lot!

I do understand everything completely about what you are politely trying to explain to me.
It is a just a justification of buying a $1000 tool to fix a $30 clock that hurts.

Thanks!

 

[R. Croswell]

Thanks a lot!

I do understand everything completely about what you are politely trying to explain to me.
It is a just a justification of buying a $1000 tool to fix a $30 clock that hurts.

Thanks!

If you only plan to fix one clock, I suggest that you just take it someplace and pay someone to fix it properly, or just have at it with your hand tools and see how it turns out. At $30 bucks you haven't got much to lose. If you plan to pursue clock repair as a serious hobby or future business the cost of tools is a long-term investment. You can buy an adequate drill press and fixtures for less than $1000, and for about $1000 you can buy a Sherline mill with fixtures, and you can do a lot more than bushings. A "bushing machine" is a one trick pony for about the same money unless you find a used one. Done correctly, I would say the mill option is potentially the most accurate, the bushing machine is arguably quicker and easier to setup, and an adapted drill press depends on a number of variables, but it at least holds a reamer perpendicular to the plate.

RC

 

[Schatznut]

So if you rationalize this with the acquisition of tools, it becomes a lot easier to swallow. "Old Tractors and the Men That Love Them" by Roger Welsch is recommended reading.

 

[Willie X]

Have you taken that Sessions clock apart yet? If not, a good exercise would be to take it apart, examine everything carefully clean all the parts and polish the pivots, then put it back together, including timing and testing. Do this about 5 or 6 times and eventually you will probably see all it's faults and also learn a lot about working on clocks. This won't cost you anything except your time and maybe some gray hair. Willie X

 

[bsg]

If I wanted to pay somebody to fix this clock, and I am pretty sure I can afford to pay somebody to fix it, I would not be bothering you here with all the idiotic questions. But, it is a hobby. I buy clocks, I fix them. I do not sell them, I keep them. Plus market here is very limited, as far as second hand stores go, and classifieds are obnoxious in the local newspaper.

Yes, I took it apart once, cleaned everything, and put it back together. I know you would politely suggest I messed it up in the process, but I did exactly the same thing to my coworker American kitchen clock circa 1947, and his was apparently sitting on a mantle of a fireplace smoking into a house, so the bottom of the movement looked fine, but the top was all covered with black soot. I took it apart, cleaned it all, put it back together, and so far it runs fine.

I ordered bushings and tools, and if nothing else I would try to replace the worn out bushings and polish all the posts, and see how it goes from there.

Thanks.

 

[Willie X]

Buying, fixing, not selling. Yep, you have the disease. No need to fight it, just buy everything you need. The disease can not be controlled and there is no cure!
Willie X

 

[bsg]

Well, just bought a used Fitz-All KWM bushing tool on eBay not to do it by hand. Hopefully it does the job.

 

[R. Croswell]

What's a Fitz-All KWM bushing tool ?

 

[bsg]

Something made and sold by somebody in US a while ago.

 

[bsg]

Something more economical than real Bergion or KWM if works out, and big waste of money if not. But it definitely was on the market for a while.

 

[bsg]

Finally had a chance to start playing with the clock and took it apart. It looks like it has no previous bushings after all, but most of the pivot holes where hammered from the inside.

This brings a question. Those indents are pretty deep. Will new bushings be able to stay in, since a lot of them will have those indents i.e. metal missing right at their circumference. Do those holes need to be filled with something before reaming?

Also, another question about bushing inner diameter (ID) selection. For example, I have a pivot, and 1.4 mm ID bushing is to small for it, but 1.5 mm fits. So, is this the correct ID bushing then, or do I need to give it some room to play and use 1.6 mm ID bushing?

Thanks in advance.

 

[shutterbug]

It should lean roughly 5°. You might find that the 1.6 is too big. In that case, broach the 1.5 a little.

 

[R. Croswell]

Finally had a chance to start playing with the clock and took it apart. It looks like it has no previous bushings after all, but most of the pivot holes where hammered from the inside.

This brings a question. Those indents are pretty deep. Will new bushings be able to stay in, since a lot of them will have those indents i.e. metal missing right at their circumference. Do those holes need to be filled with something before reaming?

Also, another question about bushing inner diameter (ID) selection. For example, I have a pivot, and 1.4 mm ID bushing is to small for it, but 1.5 mm fits. So, is this the correct ID bushing then, or do I need to give it some room to play and use 1.6 mm ID bushing?

Thanks in advance.

View attachment 741926

Depends on what you mean by "fits". I would go with the 1.5 mm that you say fits, and if it fits too tight after pressing it in, you can broach it a little. Those plates have really been abused. I don't believe a larger Bergeon bushing will cover the punched craters. If they are as deep as they look you may have a problem. Try one and see how much force it takes to press the bushing in. There are a couple ugly options, but I don't think there is anything that you can use to fill the craters that will help much before bushing.

RC

 

[bsg]

Well, I tried to put one in. Seems to stay put. Definitely needed some force to go in. Does this mean it is OK?

 

[bsg]

I guess the question I have now is which holes I need to bush, short of all of them?

 

[T.Cu]

This is a great thread for lots of us, thanks guys.

 

[shutterbug]

The basic answer is to bush only where there is considerable wear. I almost never have to bush every hole.

 

[Willie X]

You can look up, 'checking for wear'.
Willie X

 

[bsg]

So then, do I need to worry about those holes with punch markings all around them while I still have it all apart?

 

[Willie X]

Yes ...
Willie X

 

[bsg]

I guess I need to clarify.

I do understand that those holes with punch markings are candidates for bushing, since some highly qualified individual before me tried to fix those before this way. But, do I leave those holes alone if they seem to be fine (not oval, and pivots do not play much in them while running), or do I bush them all in hope that I would at least use more modern, if not more proper way of addressing the issue? And maybe longer lasting?

I.e. should I bush them if they are fine but have punch markings?

 

[shutterbug]

Yes. Punching distorts the edges of the hole away from the wear, but it doesn't go through the plate. That makes the pivots wear in deep grooves at the surfaces of the hole.

 

[bsg]

Thanks a lot for good extended explanation! Makes perfect sense. I think I did notice those groves while polishing pivots.

 

[Willie X]

You can safely assume that a damaged/punched plate hole will have a damaged, or badly worn, pivot. So, still "Yes". Willie X

 

[bsg]

By the way, for anybody interested. Fitz-All bushing tool seems to do the job just fine. Unless those bushings start to pop out all over sudden under load.

 

[bsg]

I finally got bigger size bushings, installed them, put it all back together and clock seems to be running.

Thanks for all the help! Happy New Year!