Cannon pinion problem.

[Neverenoughwatches]

Hiya watch folks. I'm looking at swapping the cannon pinion on an Oris 291 i fixed up a month or so ago. The movement had an incorrect cannon pinion fitted, same size but for a sweep second family calibre whereas the movement is a sub second, the hole in the end bothered me . So one ive just found in a donor 291 the correct one, problem is a broken center wheel pivot is stuck inside it , probably the original had the same fate. I thought about drilling it out but its certain to damage the bore. The difference between the two looks like a 2 part press fit, one with a blind hole and one open, question is finding a way to seperate the 2 pieces of both cannon pinions to swap them over.

[caseback]

Could you perhaps tap it and insert a screw to get some grip? The risk in that, is that you could be expanding the broken off piece, wedging it tighter in the cannon pinion. 

Have you considered closing the open ended cannon pinion with a bit of solder, or is that cheating

 

[Neverenoughwatches]

  On 7/2/2024 at 4:03 AM, caseback said:

Could you perhaps tap it and insert a screw to get some grip? The risk in that, is that you could be expanding the broken off piece, wedging it tighter in the cannon pinion. 

Have you considered closing the open ended cannon pinion with a bit of solder, or is that cheating

 

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I could drill the center wheel pivot with carbide but it will be too hard to put a tap through. I did think about polishing a drop of solder on the end, i would have to pack the inside to stop it sucking in. Might be an option as the 2 pieces could be a tight fit and might buckle while seperating. J do havecan offset cannon pinion remover that might prise them apart. 

If i get the blind one apart i can tap out the broken arbor.

Tapping out the arbor may even push the top off

[Neverenoughwatches]

Still looking for an idea to remove the broken center wheel arbor stuck in a cannon pinion. The cp in question has a blind hole, if i can seperate the top and bottom pieces ( risk damaging the pinion teeth ) then its just a case of tapping the broken arbor out. 

[oldhippy]

Try alum. That is what I used to remove broken screws. Mix it with a little warm water and soak. 

[rehajm]

It’s hard to tell from the photos where the break is and if there’s a way to get some purchase to split the two pieces. Hairspring cutters? 

I expect you know but this is an available  and relatively inexpensive part…

I’ll watch this thread, maybe it will help me with two broken stud screws…

Edited September 1, 2024 by rehajm

[praezis]

Did I understand well, only difference between both is an open versus closed top?

[AndyGSi]

  On 9/1/2024 at 10:37 AM, oldhippy said:

Try alum. That is what I used to remove broken screws. Mix it with a little warm water and soak.

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Would alum not also just dissolve the pinion being made from the same steel?

I've only ever used alum to remove a broken stem from a crown.

Edited September 1, 2024 by AndyGSi

[nickelsilver]

  On 9/1/2024 at 12:02 PM, AndyGSi said:

Would alum not also just dissolve the pinion being made from the same steel?

I've only ever used alum to remove a broken stem from a crown.

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Alum would attack the whole thing, it is useful in removing steel from nonferrous materials though.

 

The main issue if you try to drill it out is the center post will want to spin with the drill. Though if you hold it rather tightly in the collet it may be ok.

[Neverenoughwatches]

  On 9/1/2024 at 10:41 AM, rehajm said:

expect you know but this is an available  and relatively inexpensive part…

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I know , just a few quid but buying one isn't going to teach me anything. I dont want to be in the habit of turning to a parts supplier everytime i have a problem. I've spent 40 years of my working life getting over problems, i cant change now

  On 9/1/2024 at 10:43 AM, praezis said:

Did I understand well, only difference between both is an open versus closed top?

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Not exactly frank the two cannon pinions both came out of 291 calibres that i bought which are sub seconds watches . One had a broken center wheel arbor jammed inside and was sat loose under the dial the hands flopping around and the other at some point in its life was removed from a 292 sweep second and used in one of the 291s, the one that I'm currently working on. The cp heights are different, according to cousins 2.6 the sub and 2.4 the sweep but in actual fact measure 2.90 sub and 2.84 sweep. The incorrectly used 292 sweep cp also makes the time setting very stiff and seems to be cutting the power reserve to less than half. The pinion shoulder of the sweep is shorter and the center wheel indents are higher up so i figure its pressing down too hard on the plate pulling on amplitude and power reserve. Probably taking up all the center wheel endshake, i didn't check this before taking it off and i would rather not refit it .

I could broach it out and re-dent it further down but i still would like the correct blind hole cp fitted

[praezis]

Normally the canon pinion cannot rob power or reduce vertical play as it sits on a step of the center staff.

Repair: how about drilling a smaller hole into the closed top, push the broken part out, plug and polish the top again?

Clamping will be a bit tricky.

[Neverenoughwatches]

  On 9/1/2024 at 1:56 PM, praezis said:

Normally the canon pinion cannot rob power or reduce vertical play as it sits on a step of the center staff.

Repair: how about drilling a smaller hole into the closed top, push the broken part out, plug and polish the top again?

Clamping will be a bit tricky.

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Thanks Frank, on the incorrect 292 cannon pinion the indents are set quite a bit closer to the top than the 291. I figure to reach the step on the center wheel arbor the pinion would be pressing down tight and rubbing on the mainplate . The small hole in the top seems like the best idea

This is a nifty little vice for holding rounds I spotted a few months ago.

[tomh207]

@Neverenoughwatches Rich, isn’t that “vice” for adjusting hand tubes?

 

Tom

[rehajm]

I’m still not sure where the division of the two pieces is but…push:  the pinion upside down resting in the hole of a jeweling tool base, pushing on the stuck pivot, or in the staking set hole and a tap with a punch if you can reach the pivot…pull: leaves in a pin vise (don’t crush) plucking the top off the pinion with a removal tool. Those things grip tight!

[Neverenoughwatches]

I went with Frank's idea , besides the hole i considered it the least potentially destructive. Cheers Frank. Its on it's way out 

[rehajm]

  On 9/1/2024 at 1:04 PM, Neverenoughwatches said:

I dont want to be in the habit of turning to a parts supplier everytime i have a problem.

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…I expect your not…but now may be one of those times. (says the man what just bought yet another handful of balance staffs)…

…how about a few laps vibrating in the ultrasonic?

[Neverenoughwatches]

  On 9/1/2024 at 7:26 PM, tomh207 said:

@Neverenoughwatches Rich, isn’t that “vice” for adjusting hand tubes?

 

Tom

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Could be Tom, i haven't seen it labelled as anything in particular, the biggest holes apparently are for holding crowns while drilling out a broken stem. I think   Its just a general vice for holding round parts, wheel arbors , balances etc. But no reason why tubes cant be closed up, i usually use a pin vice.

  On 9/1/2024 at 7:41 PM, rehajm said:

…I expect your not…but now may be one of those times. (says the man what just bought yet another handful of balance staffs)…

…how about a few laps vibrating in the ultrasonic?

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Its out matey, pretty sure the only way to get these out is to pull it out or push it out. The indents hold a broken piece as firm as they click onto a center arbor.

[Jon]

  On 9/1/2024 at 7:26 PM, tomh207 said:

Rich, isn’t that “vice” for adjusting hand tubes?

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I've got one of these tools, which are great for holding crowns for removing and replacing gaskets, as well as drilling out old stems and closing up watch hands. I'll do a little review on the tool in the next day or so. In fact, I've got half a dozen new toys... I mean, tools, so could do some reviews for them. I even got some boxwood tweezers from AliExpress for about a tenner, which are mind-blowingly good for picking up  bridges and the like

[Neverenoughwatches]

  On 9/1/2024 at 7:54 PM, Jon said:

I've got one of these tools, which are great for holding crowns for removing and replacing gaskets, as well as drilling out old stems and closing up watch hands. I'll do a little review on the tool in the next day or so. In fact, I've got half a dozen new toys... I mean, tools, so could do some reviews for them. I even got some boxwood tweezers from AliExpress for about a tenner, which are mind-blowingly good for picking up  bridges and the like

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I noticed these vices a couple of months ago and really like them, they're down for next months buying only 27 quid. I've spend a shed load this month on watches some tools and something to make a semi auto watch cleaner.

  On 9/1/2024 at 7:35 PM, rehajm said:

I’m still not sure where the division of the two pieces is but…push:  the pinion upside down resting in the hole of a jeweling tool base, pushing on the stuck pivot, or in the staking set hole and a tap with a punch if you can reach the pivot…pull: leaves in a pin vise (don’t crush) plucking the top off the pinion with a removal tool. Those things grip tight!

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The hole in the top seemed safe, if the top section is tight,tapping the arbor further in to pop the cap off .....risky me thinks.

The join at 1.  At 2.  the thickness of cap end i had to drill, thicker than i expected .

[nevenbekriev]

Me thinks... there is no cap at all, this is one whole part. Yes Rich, what You did is the only solution. The broken part is loose inside and will turn when trying to drill. It is hipoteticly possible to fix the piece with shellac and then drill it, then dissolve the shellac, but what You did is easier and safer.

[Neverenoughwatches]

  On 9/1/2024 at 8:20 PM, nevenbekriev said:

Me thinks... there is no cap at all, this is one whole part. Yes Rich, what You did is the only solution. The broken part is loose inside and will turn when trying to drill. It is hipoteticly possible to fix the piece with shellac and then drill it, then dissolve the shellac, but what You did is easier and safer.

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The top section looks like a sleeve Nev but may not be, the bore of the bottom pinion runs all the through to the top.  Either way I'm chuffed i choose the correct option.

[nevenbekriev]

The top section is just the place where the hand goes. No reason to be done separately like a cap. Now I see that the whole axe has been inside. This would make drilling and extracting easier. What I thought was only the upper half is inside...

[Neverenoughwatches]

Just to solder the hole now, it isn't so bad,  i used a cut down 0.4mm carbide bit, man those things are brittle. If the drilling machine you use has some run out ( i used an old minicraft tool in it's drill stand ) the whip on the tip snaps  the full drill bit flute as it hits the workpiece and flings it across the room, i found a dead moth later that had been speared . Shaving the carbide down to 2mm helped a lot, dont know why they have around 8mm on them. The cannon pinion will be packed inside with something easily removed, probably sponge, piece of leather maybe to stop the solder running inside. I'll let you know how the fire goes

  On 9/1/2024 at 8:41 PM, nevenbekriev said:

The top section is just the place where the hand goes. No reason to be done separately like a cap. Now I see that the whole axe has been inside. This would make drilling and extracting easier. What I thought was only the upper half is inside...

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It had some grip on the inside so it may not have spun while drilling . 

[nevenbekriev]

I would not solder it. Just prepare tapered pin from iron wire, then mark to where it goes in the hole and cut smooth the front part so it will not touch the axle, then press it in the hole (+locktite is OK), cut the excess, smooth and polish

  On 9/1/2024 at 8:49 PM, Neverenoughwatches said:

moth

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Poor thing...

[Neverenoughwatches]

  On 9/1/2024 at 9:14 PM, nevenbekriev said:

I would not solder it. Just prepare tapered pin from iron wire, then mark to where it goes in the hole and cut smooth the front part so it will not touch the axle, then press it in the hole (+locktite is OK), cut the excess, smooth and polish

Poor thing...

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I'll try that nev

 

  On 9/1/2024 at 7:54 PM, Jon said:

I've got one of these tools, which are great for holding crowns for removing and replacing gaskets, as well as drilling out old stems and closing up watch hands. I'll do a little review on the tool in the next day or so. In fact, I've got half a dozen new toys... I mean, tools, so could do some reviews for them. I even got some boxwood tweezers from AliExpress for about a tenner, which are mind-blowingly good for picking up  bridges and the like

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Ordered the vice Jon but I'll still read your review .   What i like about it , you can make a series of your own clamping plates with different profiles to hold anything you want. 

I keep looking out on ebay for the BHT ( same brand as the trupoise ) vice, sell for around 30-50 quid, i think this Chinese one will have more application.

Toys you say........ i wouldn't dare describe them this way if my missus asked what it was for,   " Its an essential tool that i can't do without darling, whats that you're running out of that perfume you like "