Waltham 1908 – Bent guard pin??

[sstakoff]

Waltham 1908/grade 610 7jewel…

Watch was in pretty good shape mechanically – I cleaned and oiled.
Using a microset 3 timer – watch is in beat within 4ms. Generally timed out between 17998 and 18002 in 6 positions so I was
pretty happy. BUT – this bad boy seems to just stop once in a while and I’m a bit stumped. I suspect there’s an issue somewhere
in the escapement so I will do some under-microscope inspection tonight. One thing I did notice is the rather bent guard pin
on the pallets – pic attached. Is this normal for this model or could it be that someone replaced with incorrect pallets or perhaps
with incorrect roller????

Stu….

[chris mabbott]

I can’t say if it is correct for this model, but you do see pins formed into the ? Shape, it isn’t uncommon.

You’ll have to apply a little Prussian blue around the roller and check for contact points. Don’t use black marker pen as it dries hard and does not give a good indication of contact spots..

There are many tests to perform as we never know the history of these old watches or what has been replaced, modified or made to fit by previous repair type persons..

[bernie weishapl]

I have seen a couple like this. I use the black sharpie to see where it contacts and then use denatured alcohol to clean it off. Takes it right off.

[chris mabbott]

Bernie, I use a sharpie to mark material that will be cut or drilled, but for checking the roller contact, because the ink is permanent, and it dries quickly, there is not enough force contact between pin/roller (it takes nothing to stop the action) to give an accurate reading, as in, it will ride over the permanent ink without removing it, so you could have a bind spot and not see it.. Usually during the time it takes to reassemble the parts, the ink is dry..
You also have to be very careful when cleaning it off with alcohol that you don’t get any on the roller jewel shellac.

I prefer the Prussian blue because it doesn’t dry hard, it isn’t permanent and it is made for just this purpose, checking contact clearance, and for laying out of course.. I think they make two types now, once is none drying and the other dries soft..

[randy]

Stu,
If this doesn’t yield any results, wind the watch, set it to twelve straight up, and then note what time it stops. Repeat the test and see if it’s stopping roughly at the same time.
If it does, you probably have a bent gear, or bad tooth on one of the wheels.

Let us know how it’s going !

Randy

[david pierce]

All I can see is a blurred greenish colored picture. Is everyone else getting a sharp focused picture of a watch movement?
david

[Bob Tascione]

Hi David,
It wasn’t you. The pic needed to be converted from png to jpeg and then resized. When posting pics on the forum it’s good to size them somewhere around 600px for larger of the 2 pic. dimensions. Makes it a lot easier to view for everyone and keeps the file sizes down on the server.
There’s a thread at the top of the General forum on how to manipulate and post pics that Chris posted.
Bob

[sstakoff]

Sorry Bob – thanks for fixing.

[Bob Tascione]

No problem Stu
Lot’s of members have no way to resize them or have problems when they try so when that’s the case best to just put them up here and we will do the resizing. I actually don’t mind sizing them at all. If you do have a way to do it though going somewhere around 600pxs to 700pxs works great. Otherwise the pics may sit up here at a difficult and sometimes impossible to view size for a few days before one of us can get around to resizing them. Sometimes when traveling around using my mini iPad I’m not able to make out a pic no matter what I try. I would imagine others run into the same problem.

Bob

[david pierce]

Stu,
The purpose of the guard pin and the safety roller is to prevent the pallet from moving when it is not supposed to move. The safety roller has a notch machined into it to allow the guard pin to pass during impulse. The guard pin therefore has to do two things:
1) It must pass through the notch on the safety roller and allow the pallet to move to the other banking pin during the normal timing cycle.
2) It must prevent the pallet from moving to the other banking pin if the watch is bumped or jarred and the impulse jewel has not yet hit the pallet fork. In other words, the pallet is supposed to be stationary and some force other than the force from the balance wheel made it move.

Whither the guard pin is horizontal and straight or vertical and bent, it must perform these two functions. This may not help you decide what to do with the strange looking guard pin but if it was me and it worked the way it is supposed to work I would leave it alone.
david

[maitai11]

David,

Thank you for that concise explanation. It’s good to have “another way of saying it”, and your way makes a ton of sense. Thanks again.

Tim

[chris mabbott]

My Granny used to say…. Never go out in public with a bent guard pin, I always presumed she was talking about my pocket watch 🙄 But this thread has cleared up that mystery and connected all the dots 😆

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