Strange behaviour - Jauch drop octagon wall clock

[Rockin Ronnie]

This is a German made Jauch clock from the 1970s, I think. It is time-only spring driven clock. All I did was oil it when I got it.

It runs a full 8-day cycle with no problem. However it gains about 5-7 minutes at the beginning of the cycle and loses the same at the end of the cycle. Is it the nature of the movement or should I look further for other issues?

Ron

 

[Willie X]

Ron,
No, I own several of these and they are pretty good time keepers. Look for scored pivots and worn barrel arbor holes. The pivots are small, a light touch with a good buff stick and a minimal polish along with pegging and round broaching the holes will usually do it. The barrels are another matter, if worn, you will have to make bushings for these. The cap is to thin to bush without making a thin flange or leaving the bush a bit proud and peening both sides. The barrel is narrow and they really get th wobbles when worn. Check the little click wheel closely for dammage while you're at it. This is a really cheep movement but finely made and well engineered. An overhaul should result in another long run.
Note, the escapement doesn't give much trouble but someone may have misadjusted it. Make sure that it is running as a dead beat with every tooth falling well onto the dead fades of the pallets. Thes clocks have a wide pendulum swing.
Good luck,
Willie X

 

[Kevin W.]

What a co incidence i have one too, was wondering if they were well made or not. Its a customers clock, i was considering replacing with the same movement.

 

[Rockin Ronnie]

Ron,
No, I own several of these and they are pretty good time keepers. Look for scored pivots and worn barrel arbor holes. The pivots are small, a light touch with a good buff stick and a minimal polish along with pegging and round broaching the holes will usually do it. The barrels are another matter, if worn, you will have to make bushings for these. The cap is to thin to bush without making a thin flange or leaving the bush a bit proud and peening both sides. The barrel is narrow and they really get th wobbles when worn. Check the little click wheel closely for dammage while you're at it. This is a really cheep movement but finely made and well engineered. An overhaul should result in another long run.
Note, the escapement doesn't give much trouble but someone may have misadjusted it. Make sure that it is running as a dead beat with every tooth falling well onto the dead fades of the pallets. Thes clocks have a wide pendulum swing.
Good luck,
Willie X

Thanks Willie X. I thought it was odd the way it was behaving. Off the wall it comes and I will look at the things you suggest. I will post back if I run into serious issues.

How does yours run Kevin? Keep good time?

Ron

 

[Kevin W.]

Hi Ron, no mine is all gummed up, needs to come apart and be serviced.

 

[Rockin Ronnie]

Willie X, I was not sure what you meant until I took the movement apart and discovered the worn cap you mentioned. There is quite a gap and there is a wobble as well. Now to strategize how to fix it.

The ratchet and click look good. Otherwise the movement requires at least 3-4 bushings.

Ron

 

[Tinker Dwight]

If ti is in fact a strip dead beat, it should be doing better
than that.
I have a cheap open spring Korean 31 day movement with
a light ~6 pendulum.
The first week it gains about 1.5 minutes and slowly
loses it by the end of the month.
A barreled spring should do better.
Tinker Dwight

 

[kinsler33]

Ron,
No, I own several of these and they are pretty good time keepers. Look for scored pivots and worn barrel arbor holes. The pivots are small, a light touch with a good buff stick and a minimal polish along with pegging and round broaching the holes will usually do it. The barrels are another matter, if worn, you will have to make bushings for these. The cap is to thin to bush without making a thin flange or leaving the bush a bit proud and peening both sides. The barrel is narrow and they really get th wobbles when worn. Check the little click wheel closely for dammage while you're at it. This is a really cheep movement but finely made and well engineered. An overhaul should result in another long run.
Note, the escapement doesn't give much trouble but someone may have misadjusted it. Make sure that it is running as a dead beat with every tooth falling well onto the dead fades of the pallets. Thes clocks have a wide pendulum swing.
Good luck,
Willie X

Well, I'm learning a lot here. How would scored pivots and/or a worn barrel affect timekeeping, at least insofar as the clock continues to run and the escapement isn't skipping? All I can think of is that the pendulum length has been set to minimize the error over 7 days, which implies that the worn barrel and/or pivots were slowing the clock down quite a bit as the spring tension declines. So you'd have to set the pendulum so the clock runs faster just after winding.

Is this relatively correct or am I, as often happens, missing something?

M Kinsler

 

[Willie X]

Most modern clocks will keep time within 1 minute per week. The clock in question will easily do that rate but this depends on adequate power to the escapement with very little fluctuation in that power.
Ron's clock had probably stopped? When you oil a worn out clock the worn parts will ride eraticaly on the oil for a while and eventually stop again. When he restores normal operation, the clock will once again keep good time.

When you are working with an old clock with heavy springs, recoil escapement, short and/or light pendulum, the pattern you described can be expected, to some degree. This might not be due to wear at all, but design. Although, worn parts can always make things worse.
Willie X

 

[Tinker Dwight]

With tension, the escapement wheel tends to shift.
This can significantly change the location the pallets
touch the escapement wheel. A slightly warn pallet
where the transition between lock and impulse can
change the impulse pattern.
All most clocks are sensitive to the impulse strength.
The exception are thing like gravity escapements where
the winding power is just used the reset the drive.
Using barreled springs and deadbeat by them selves should
improve the rate to some extent. The barrel should have
more uniform power and the deadbeat should be less
sensitive to the amount of power.
Tinker Dwight

 

[Rockin Ronnie]

I can install the 3-4 bushings elsewhere on the movement with no problems. However I am still worried about the cap and the amount of "slop". How much slop is acceptable as I have not run into this situation before?

A possible solution. I have a 8.50 mm (with inside dimension of 6.5 mm) bushing I can install with a Bergeon 8.47 mm cutting broach. The diameter of the winding arbor coming through the cap is 7.42 mm. If I cut out ~1 mm with a 7.47 mm cutter, the wall of the bushing would be ~1 mm thick. Is that too thin and am I taking a chance?

Ron

 

[Rockin Ronnie]

Better view of the gap.

 

[R&A]

Do you have the machinery to make bushing for the caps and barrels? That is pretty worn. This will have allot to do with the time fluctuation.

 

[Rockin Ronnie]

Do you have the machinery to make bushing for the caps and barrels? That is pretty worn. This will have allot to do with the time fluctuation.

Unfortunately I do not. Volunteers?

 

[shutterbug]

You can buy new caps. Measure it and see if there's something close. You could carefully reduce the size a little if you really needed to.

 

[Kevin W.]

Good idea i was going to suggest a new barrel, but if you can buy the cap only, that is better.

 

[Willie X]

These caps are not available. Bugs probably has the best suggestion with modifying a Hermle (or similar) cap, try to find a brass one.
I have rebushed several (as already mentioned) but the cap is so thin with very little space for a flange. I would bore the cap to center and make a small chamfer on the inside edge of the hole. Make a bushing with a 1mm flange (more if you have room) and long enough to protrude 15 thou inside the cap. Peen or stake the inside well into the chamfer and dress off if necessary. This will double the cap's wear surface but make sure you smooth and polish the arbor well, so you won't have to do this again. ☺ Ha

 

[Tinker Dwight]

I would think one could cut back the spring arbor's shoulder to allow for a
thicker bushing. You'd just keep the bushing flange a smaller diameter
than the arbor where the spring sits. That way it wouldn't drag or
catch on the spring.
Tinker Dwight

 

[Rockin Ronnie]

Thanks for all the feedback. I now have a very good understanding of the problem and will consider the solutions presented.

Ron

 

[shutterbug]

Timesavers #'s 20971 through 20983 are barrel caps (covers) made for Hermle.

 

[R&A]

Timesavers #'s 20971 through 20983 are barrel caps (covers) made for Hermle.

If he doesn't have the machinery to do this then why. Plus aren't hermle caps made of steel

 

[shutterbug]

If he doesn't have the machinery to do this then why. Plus aren't hermle caps made of steel

I believe they are steel. The sizing can be accomplished with usual shop materials and a bit of inventiveness. One possible is a bolt the size of the hole, two nuts and a couple of washers to hold it on, cut off the wrench end and mount it in a slow speed drill, then use a file to slowly grind it to fit. Safety glasses, of course

 

[R&A]

I believe they are steel. The sizing can be accomplished with usual shop materials and a bit of inventiveness. One possible is a bolt the size of the hole, two nuts and a couple of washers to hold it on, cut off the wrench end and mount it in a slow speed drill, then use a file to slowly grind it to fit. Safety glasses, of course

U have got to be kidding me

 

[shutterbug]

U have got to be kidding me

Why? I've done it a few times on my lathe. It's not tough to accomplish. Of course, with a drill you'd want to secure it and fashion some sort of rest for the file. It's much easier to do that than to try to find center and put in a bushing.

 

[R&A]

Why? I've done it a few times on my lathe. It's not tough to accomplish. Of course, with a drill you'd want to secure it and fashion some sort of rest for the file. It's much easier to do that than to try to find center and put in a bushing.

Sorry I don't support this idea with the drill nor would I say such a thing. And no it isn't easier than finding center for a bushing. Where did you come up with this idea. This could hurt somebody really bad. Files really.
Definition R&A Sometimes we are retarded and sometimes we are advanced. Well slow or fast this just keep getting better this here clock repair.

 

[shutterbug]

Well, R&A, we try to help folks with limited tools and/or knowledge to get into repairing their own clocks. Granted, sometimes the suggestions run counter to what a skilled person with a machine shed full of tools would prefer. I have no doubt that you are skilled and have great tools. I also have the tools needed, and feel pretty confident in my skills as a repairman. However, we have people stopping by this MB who have neither the tools nor the experience, and it's not always helpful to just tell them to take the clock to a repairman. I've had issues with machinists before about using drills for common tasks, so it's not new for me to be rebuffed. I have recommended using drills for polishing pivots, large tapered reamers for inserting bearings, and now a drill for sizing a barrel cap (I'm sure you remember) . I know I could successfully demonstrate how those tools are "good enough" for what needs to be done. As a machinist, you have a narrower vision of what is acceptable. That's OK. We have many very skilled machinists who regularly contribute and share their knowledge here. Fantastic. We also have a whole thread devoted to home-made repairs that make us cringe .... but that got the job done and likely saved a clock from the landfill. Doing what you can with what you've got is a pretty common idea here. We offer suggestions on how things might be approached by a novice, and quite often they surprise us with a successful repair.

 

[Willie X]

Bugs,
I have worked in and around Machine Shops all my life and the practice of using a flat file to smooth and dress machined parts is common, if not universal.
Willie X

 

[R&A]

Go for it. Lets see a video of this from one of you. In a drill with a file and grinder. And the cap fitted to a barrel. And the cap mounted on a bolt with 2 nuts. I would fire anybody I saw doing this.

 

[shutterbug]

It seems you just want to agitate, R&A.

 

[Kevin W.]

R and A just because you dont wish to use this method, i dont put folks down that try to help others on here, and i do agree with what Shutt and Willie have said. And i do work in a machine shop.

 

[BLKBEARD]

Being that we are talking brass, which is fairly soft & thin. You could cut your caps with a brace drill & an adjustable cutter such as this.
http://www.ebay.com/itm/Drill-Press...160835?hash=item44037ae143:g:ZTwAAOSwZKBZF0HA

You could also cut them with a hole saw in a Pistol Grip Drill. Sandwiching the brass sheet stock between two pieces of plywood, such as this. if you can find one of a close diameter.
http://www.ebay.com/itm/Vulcan-9423...009581?hash=item237920366d:g:1UIAAOSw-0xYeAYu

The tools I linked are just to illustrate the type of tool, not the actual ones being offered for sale.

There are work-arounds. Some are a bit unorthodox, but they'll get it done. I'm a firm believer in using the right tool for the right job. At this stage of my life I'm Well Tooled, but it wasn't always that way.