New direction - 400 day clock ID confirmation

[Garfield]

First ever post here - hope it is OK that it is a question not an 'about me' ....

I typically play in the watch arena but I'm venturing into clocks too - I acquired this from somebody local to me for a can't refuse price, it does run but I plan to service it before it runs in anger.

I believe it to be a JUF Jahresuhrenfabrik pre 1920 or so but I'm guessing and basing this on similar clocks that I've seen. The dome is glass not plastic, the serial number is 86092. The 'pendulum' is measuring at 120mm by 0.08 by 0.66 (the latter is the width and tricky to measure), I have no clue if this is correct but it does not hang how I'd expect - aka not vertical when the clock is horizontal, don't know if this is correct or not - these clocks are new to me. The bottom pendulum block doesn't look right, looks a bit 'diy' - need a pic of a good one or a source of same - or even good parts for one of these, the top pendulum support seems to have suffered some in its day too. There's no slop in the gear train, no rebushing required so all in all it ain't too bad, tempted to just lube it but the OCD is kicking in as it does with any 'unknown' mech on my bench.

Anyhow enough of that - what is it, how old is it, what did a buy - pig or poke - (I like it whichever ...)

 

[KurtinSA]

Welcome to the message board...and to the world of 400-day clocks! It does appear to be a JUF, probably close to 1910 or so given the serial number. I have several JUFs from 1912-1913 with six-digit serial numbers.

The bottom block is definitely DIY. It should be more like a "standard" block with two rectangular halves held together by the small screws. I can see that the anchor pin is not pointing vertically...it really should be...having it off at an angle increases the forces needed to move pin/fork during operation. If it were vertical, I wonder if there would be a conflict with the legs of the saddle bracket. I'd be careful trying to bend that if you were to try...it could be brittle and thus break off...I've always been leery about bending those.

The top part of the suspension unit looks pretty standard for this timeframe. I think this is called a "C gimbal" or "C bracket" or maybe a "G" if you prefer. It might have been overly complicated but seems to work well.

The main spring might need a look-see to get full benefit out of the winding. I might try and get it running to see how strong it is. If it seems to run weakly, then it probably could stand a good overhaul.

Kurt

 

[Garfield]

Much appreciated, I have a tendency toward OCD when it comes to correctness. Near as I can tell there is a standard suspension available 6789 Horolovar that matches the current set up 'mostly' but it won't work with the swivel / G mount at the top. I'm currently trying to understand how that works. I think the pin would foul the saddle bracket, how hard would it be to re-pin ? I wouldn't try to straighten in situ, I'd want the pallet secured (if that's what it's called on a 400 day / deadbeat) so that would be a tear down.

That said even the fork looks a bit DIY - I'm not happy with it that's for sure - I'm just trying to learn what's needed to make this right. When it came to me the balance was off centre - the screw that centres the weight adjust has a flat nose and something tells me that's wrong too - should be conical to run in the groove in the adjuster ? It runs but I wouldn't know if was weak or strong, don't have that kind of experience yet.

 

[etmb61]

Thanks for sharing your very nice early JUF. You should check the bottom of the pendulum for a written serial number. If you find one it will match the number on the movement if it's the original part. That's always a plus. Like this one:


It looks like it has been well kept, but it does have a couple of issues. It looks like the pendulum hook is bent down from being dropped or hit. If it works like that I find it best to leave it alone. I've broken every one I've tried to straighten and end up making new ones.

The barrel looks like it has a slight bulge at the hook (the reflection in the picture is distorted).

Another one of those if it works don't fix it, unless the hook is loose or the spring won't catch.

The last thing I see is the anchor pin is bent well forward of vertical. This can be a problem with how the clock runs. It should be as vertical possible. It's also very easy to break off. Some are threaded and some are pressed in. Be very careful if you decide to correct it.

Eric

 

[Garfield]

It winds OK - I'm tempted to 'unwind' it for now - the barrel does have a bulge - I hadn't spotted that. There is no discernable writing on the pendulum. I have the tools for pressing and staking if needed but breaking stuff that can't be replaced is not on my agenda, replacing stuff that doesn't belong is however.

I'd say the saddle is kicked up some where the swivel is located but that thing flops about all over the place - can't find much info so far on how such a top mount should be.

 

[etmb61]

Your fork is an original part!

Eric

 

[KurtinSA]

The anchor pin on my similar period JUF is about as long and points straight up. It doesn't foul the saddle legs. Of course, one can look from the side and see if there's clearance. On your one picture from the side, it looks like there might be. Or at least the pin could be returned to a more vertical position but just short of and I think it would clear.

I don't see anything horribly wrong with the top c-gimbal. The spring attaches to the bottom and the forces resolve so that it pulls down right where the top conical screw is. It screws into a block which can be turned left or right to adjust the beat. The screw on the side of the saddle locks that block into place.

Kurt

 

[etmb61]

It winds OK - I'm tempted to 'unwind' it for now - the barrel does have a bulge - I hadn't spotted that. There is no discernable writing on the pendulum. I have the tools for pressing and staking if needed but breaking stuff that can't be replaced is not on my agenda, replacing stuff that doesn't belong is however.

I'd say the saddle is kicked up some where the swivel is located but that thing flops about all over the place - can't find much info so far on how such a top mount should be.

The suspension is designed to give some fore and aft movement and still allow beat adjustment. It fixed one of the problems with a solid upper block but probably created others. It was replaced by the simple block with a pin or screw that accomplishes the same thing.

The top screw should have a point at the bottom to allow the assembly to pivot. It should be adjusted so there is a gap between the top of the lower arm and the bottom of the pivot plate (see arrow in picture below).


The tip of the screw rests on a part (pivot plate) which is turned to set the beat. It has a slot that holds the small tab and keeps the assembly in line.


The larger screw on the side of the bracket locks the beat adjustment. I like to set these so the beat can be set by hand but not so loose to be moved by gentle contact.

Hope this helps. I need to take some other pictures.

Eric

 

[Garfield]

Much appreciated - it hangs a lot better now - the spring itself was not centered so it was kicking things out - the weight was not below the point of the screw / pivot. I think it is time to get some 'bits' and replace the bottom support block (the diy pendulum hook which I shall retain for posterity).

That plate for setting the beat was loose - very loose ....

"Your fork is an original part!" ---

I need to sort that pin and the pallet depths - presumably that's standard for any deadbeat escapement and nothing special on the 400 day clocks ?

You can clearly rotate something in the back to raise / lower and offset the pallets - still reading .... no fiddling until understanding ....

 

[etmb61]

There's no reason to adjust the pallet depth unless the clock won't run!!! Then you must understand that it is not a logical correlation to gravity clocks or watches.

If your clock looked like this then I'd say there's reason to suspect it could be out of adjustment:

But I would still test it first!

 

[KurtinSA]

As Eric points out, unless you see evidence of someone mucking with the escapement, you should first leave it alone and assess things. In looking at the eccentric slot on one of your pictures, it looks like it hasn't been touched. That's a good sign!

Kurt

 

[Garfield]

It is currently 'under test' with the suspension re-adjusted as per previous post. There's very little overshoot, the lock and drop isn't clean although the clocks been running an hour now. Each tick is pretty much at the end of each spin - if that makes sense - not quite at the end but not far off and there's a minimal wind on the clock right now. Just doing some deadbeat study.

Edit : Question : Should the pin do a little dance at the end of each lock and drop cycle - for each it seems to snap back a little before continuing - is this normal or should it be smooth.

 

[KurtinSA]

The pin movement is normal. This is the escape wheel tooth falling off the impulse face and then another tooth hitting the lock face.

With no run-on after ticking/tocking, doesn't sound like there's much power. It might build, so keep testing. As you're aware, you need the overshoot for the clock to run. Total rotation is not really the goal...decent overshoot is what you want.

Kurt

 

[whatgoesaround]

The overshoot is possible to increase by lowering the fork, very small increments. With the fork placement you have, there might not be much room, but this can be accomplished by flipping the fork over. This will change the amount of suspension spring between the fork and the upper block and allow more of the spring to be available.

 

[Garfield]

Well aren't these clocks a challenge. When I first got the clock it gained an hour a day - but the pendulum and suspension wasn't in good shape setup wise.

Corrected all that and the clock gained a couple of minutes overnight so it's better but I decided to slow it down some, wound the weights out a bit, put some more wind into it and - yep I knocked the spring and its support so I spent an hour getting it back in beat before it would run again.

I don't think I can get the fork any lower without fouling the backplate - was reading all kinds of stuff about these clocks last night - the head's awash. I still don't like how the escapements working, it isn't clean, the 'exit' pallet is not entering clean but seems to hang on the very tip of the last tooth of the escapement through. I'm finding it very hard to see where the pallets are actually contacting - it is certainly different when spring driven or screwdriver tip.

The current overshoot is 15 to 20 degrees once settled down.

 

[etmb61]

Here is a good running Schatz 49 escapement in action. Yours should look about like this one.

You can see the anchor pin has a bit of recoil when the tooth drops off the pallet. I don't think other types of dead beat escapement clocks have that. Also look at how the fork and anchor pin interact. Notice the gap between the fork and the pin. This should be as close as possible without binding. Lost motion here reduces the length of the impulse. If you follow the tip of the pin, you can see that the locks are equal, the impulses are about equal, and the over swing of the pendulum is about equal. It's in beat. If you watch the escape wheel you'll notice the drops are not equal. They don't need to be.

Eric

 

[Garfield]

a trillion thumbs up - that's exactly what it's doing - family has owned a couple of long case with dead beat escapements and they sure don't do that.