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Brass bushings for watches

DouglasSkinner
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DouglasSkinner WRT Addict

DouglasSkinner

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I have a nice old Elgin 7j (Model 291) pocket watch which I've just resurrected.  It's running a little fast and possibly the reason is that upper bushing for the escape wheel is a little bit egged.  I'm going to have to replace it.  The question is how?  Should I find a jewel which fits and make a setting?  Or should I make a brass bushing.  I say brass because the original bushing is just the plate itself and so is plated brass.  The lower bushing looks fine.  Should it be replaced too?  Any suggestions?

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vinn3 Distinguished Member

vinn3

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i sugest replacing the mvt..in the old days,when men wore the watch in a vest pocket,,  that is what they did.  the case is very nice.   vin

DouglasSkinner WRT Addict

DouglasSkinner

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9 hours ago, vinn3 said:

i sugest replacing the mvt..in the old days,when men wore the watch in a vest pocket,,  that is what they did.  the case is very nice.   vin

It is a nice case.  A "fold out".  I've been refurbishing it.  It's got a plastic crystal which I think I'll replace with a vintage glass one.  As for replacing the movement itself, I'd be interested in upgrading the quality if I can find one.  Not sure which Elgin 16s movements will fit in the case.  Naturally if I do repair it I know I'll never get back the investment of time.  I do them largely to practice my skills.  I could re-jewel it but I think I'll practice turning a bushing instead.  I can see already that the movement is very forgiving.  The escape wheel pivot hole is pretty egged.  I put it together and let it run for a day and it kept time--not great but surprising, nonetheless.  Re-bushing will probably reduce the positional errors somewhat; though I'm not very experience in this area.  Thanks for your comment.  Doug

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DouglasSkinner

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9 hours ago, watchweasol said:

Hi   If you are going to repair the watch I should use a brass bush as that keeps the watches integrity, thats what the old guys would have done.

I think you're right.  I need to practice my lathe skills anyway so I'll give a try at turning a bushing.  Thanks for the comment.  Doug

nickelsilver Distinguished Member

nickelsilver

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A bushing will be fine. What will be tricky is getting the hole open large enough for one without drifting its position. The best way to do it would be in a faceplate using a cross slide to bore the hole. Lacking that, you can  drill it, smaller than desired, and correct any error in concentricity with a round file comparing with the original oil sink. You'd want to be close to the edge of the oil sink by now, and can now ream it out with a jeweling tool and turn up your bushing to fit. As it's the upper hole, it's quite a ways away from the wheel itself so a small error in placement won't have much effect if any. It's way more critical on the lower one which is right next to the wheel.

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vinn3 Distinguished Member

vinn3

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18 hours ago, watchweasol said:

Hi   If you are going to repair the watch I should use a brass bush as that keeps the watches integrity, thats what the old guys would have done.

    the "old guys would go to the jeweler" and have a NEW movement installed.  now there are no new mvts.!  i have my grand father's pocket watch.  vin

vinn3 Distinguished Member

vinn3

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9 hours ago, DouglasSkinner said:

It is a nice case.  A "fold out".  I've been refurbishing it.  It's got a plastic crystal which I think I'll replace with a vintage glass one.  As for replacing the movement itself, I'd be interested in upgrading the quality if I can find one.  Not sure which Elgin 16s movements will fit in the case.  Naturally if I do repair it I know I'll never get back the investment of time.  I do them largely to practice my skills.  I could re-jewel it but I think I'll practice turning a bushing instead.  I can see already that the movement is very forgiving.  The escape wheel pivot hole is pretty egged.  I put it together and let it run for a day and it kept time--not great but surprising, nonetheless.  Re-bushing will probably reduce the positional errors somewhat; though I'm not very experience in this area.  Thanks for your comment.  Doug

   there are many used mvts. out there.  elgin had a 21 jewel one in their "rail road watch"  would fit in your warch. vin

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yankeedog Distinguished Member

yankeedog

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Regardless, something has to be done about that bushing. You aren't doing that movement any favors in running it that way. Egg shaped holes mean misaligned shafts, misaligned shafts mean misaligned gears, and a cascade of new problems.

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DouglasSkinner WRT Addict

DouglasSkinner

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37 minutes ago, yankeedog said:

Regardless, something has to be done about that bushing. You aren't doing that movement any favors in running it that way. Egg shaped holes mean misaligned shafts, misaligned shafts mean misaligned gears, and a cascade of new problems.

You're absolutely right!  I just let it run a short while.  It's now disassembled and I'm making ready for repair.  

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DouglasSkinner

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7 hours ago, nickelsilver said:

A bushing will be fine. What will be tricky is getting the hole open large enough for one without drifting its position. The best way to do it would be in a faceplate using a cross slide to bore the hole. Lacking that, you can  drill it, smaller than desired, and correct any error in concentricity with a round file comparing with the original oil sink. You'd want to be close to the edge of the oil sink by now, and can now ream it out with a jeweling tool and turn up your bushing to fit. As it's the upper hole, it's quite a ways away from the wheel itself so a small error in placement won't have much effect if any. It's way more critical on the lower one which is right next to the wheel.

Thanks!  I'm not experienced enough to envision how to use a faceplate and cross slide to bore the hole.  Do you have any pictures so I can see how it works?  I have a Seitz jeweliing tool and I was just going to use one of the reamers to bore out the hole in the plate.  I've measured the diameter and think a number 230 reamer will work (actually 2.99 mm).  I plan to turn down some brass stock to 2.30 mm.  Then I plan to drill a hole (size 24 as near as I can tell) a little undersized.  Measuring the thickness of the plate will tell me how thick the bushing needs to be and I'll part it at that thickness.  For me the tricky part will be fitting it into the hole.  I'll need to get the outside diameter right so I won't have either a loose or overly tight fit--my lathe skills aren't all that great so I may have to make several attempts.  Then I plan to use a small broach to bring the hole to the proper diameter.  Check for end shake and side shake.  Spin it in place and then in train with the other wheels.  If it spins okay and all looks properly righted I assume it will be okay.  How does that sound?  Thanks again!  Doug

watchweasol Distinguished Member

watchweasol

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Hi   Lacking a lathe or bushing tool that sounds ok  just take great care in getting the hole  round and vertical. It is always stated in the books to work from the reverse side when bushing as the broaches/reamers are  tapered therefore when the bush is pressed in its a tight fit. I bush clocks by hand after drilling out the plate using a drill press undersized then finish with a broach. The bush should be level with the front plate and countersunk for an oil sink, any finishing done on the reverse side, patience and care are the watch words here.  Spinning it in place with its adjacent wheel and checking for depth and freedom before fitting the rest of the train is a must.

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