Simon,

As Russell suggests … a substantially oversize bushing would be best.

You could even make a virtue out of necessity, and jewel the hole.

… or show-off a little, by inserting a chaton  

MichaelG.

Edited By Michael Gilligan on 22/08/2013 14:18:18

Edited By Michael Gilligan on 22/08/2013 14:29:39

The correct way is as suggested to drill and ream an oversize hole sufficient to completely encompass the location for your pivot. A push fit brass bush is made slightly longer than the plate is thick. This is then rivetted into the plate with a small hammer. Each side is then dressed off with fine files and/or emery sticks and polished. You should be able to do this and not see the join providing the materials are the same.

PS do not deburr the hole or you will get a ring around the bush. The mark of an engineer is not that he doesn't make mistakes but he knows how to fix them when he does.

regards Martin

Simon

Martin has it right. After years of footlin' about with ME, for a change, I enrolled on an evening class run by a local clockmaker. He was very successful at repairing clocks but the methods employed were not those of model engineers – his tool box by comparison with ours was rudimentary and I thought MY workshop untidy at times – you should have seen his. It was all a bit of a culture shock! If a hole is in the wrong place or if it is too worn then open it up and put a bush or plug in. As has been said before on this forum forget precision fits with clocks and just make sure everything has clearance and is free to run – friction is the enemy. Once you have done as Martin suggests you won't be able to see where you have inserted the plug. Just think – when some clock repairer comes to look at your clock in a hundred years or so he will likely do just the same with the worn holes on the plates and think nothing of your plug if he finds it. How about a 'photo of your progress?

Regards

Norman

yes mike has it been there t shirt et all; yes this method will save hours of makeing a new part

bob

I cannot agree more with John about hammering plates, sadly clockmakers use such methods not only out of ignorance but also for economic reasons, you do not get rich from reparing clocks. A good way for fitting bushes in tapered reamed holes, is using tapered bushes, either bought or self made. Place the larger diameter at the inside of the plates and rivet the other side, you will get a perfect fit without the need of using solder. Niko.

MichaelG, Brilliant link, best laugh I've had all day, unbelieveable what some people will do, I'm just thankful I didn't have the job of sorting that mess!

Niko, longcase winding barrel bushes in 3mm thick plates running 10mm diameter winding arbours will not take kindly to having new bushes reamed to size, they will turn no matter how tight you stake them, solder is the only way to effect a secure and virtually invisible fit!

These days I actually fit stepped bushes on the barrel arbours as it provides more support via an extra 2mm flange of the front of the plate, and with a 5 kilo weight hanging from them they need it, it slows down wear and is totally reversible should down the line, a restorer with anal views on 'originality' deem them unsuitable!

Smaller bushes are best reamed both sides of the plate with a tapered reamer, a parallel sided bush inserted and then staked, the bushing is then secured both sides of the plate with no chance of them coming out or loose, the solder is just for large bushings, but perhaps I didn't make that clear, apologies if not!

John

As a side note to my last comment, the exception to the solder on large bushings, would be on smaller bushings on American and German clock plates where they carve out so much metal there's near damn all left to suppot the staking of a bush!
If there's a risk of the plate edge 'belling out' when you stake the bush because the hole is close to the edge, solder it rather than deform the plate, if the plate deforms, it changes the pivot depthing and the bush won't be tight!

John

Edited By RJW on 22/08/2013 22:36:01

John, I had smaller sizes in mind, more like this **LINK** , sorry do not know what they are named in English. Niko.

Just bushings or less frequently Chatons Niko, Chatons are generally a referance to screw set jewel settings in pocket and wristwatches, where the jewel is set in a brass or gold setting then the whole is screwed into the watch plate – generally only on high grade movements!
often for really small size and odd ball bushings, I'll cut them from a length of bushing wire!

Those bushings shown in the link are certainly small, getting down to pocket watch sizes there, which are similar in sizes to the upper end of French drum and and high grade Vienna regulator wheel trains!
If they work for you and you're happy with the result and make a good repair, I'm certainly not going to argue about them!
You're also fairly unlikely to have a broach jam in a bush and turn it at those sizes!

I have to confess that these days, I use Bergeon bushings together with a Bergeon bushing tool, the bushes are machined to specific sizes and have a related reamer similar to a 'D' bit for cutting holes in the plate, the hole and the bushes are also parallel sided and lightly staked, but they broach easily and make an invisible repair the way i do them, and up to their maximum diameter of 8.5mm, rarely turn in settings, but I'll still solder them in really 'iffy' plate positions such as winding barrels or hammer arbours sitting close to plate edges when I'll touch the hole with a taper reamer so there's a seat for the solder to flow!

That being said, I did originally broach everything by hand and eye, but the final broaching to suit individual pivots still has to be done by hand, because after repairing and burnishing them, pivots are always random diameters!
I didn't mention the Bergeon routine earleir because it's very unlikely anyone here other than a pro' repairer/restorer will have invested that kind of money in kit to re-bush clocks, but for me, it cuts the time to rebush longcase, Vienna and French drums by at least half – I also confess enjoying the luck of the Gods when turning up at an auction room got the whole shebang including a full complement of bushes for half the cost of the reamer and staking set!
I would also say to anyone thinking of going the Bergeon route, learn to broach and bush by hand first, that way you'll get your eye in and bushes will always be accurately placed in the plates and pivots similarly!

Going back to Simon's OP, depending upon the diameter of the pivot, he may get away with just bushing the plate in the correct place, but only if the edge of the bush removes the edges of the old hole, if it won't, he'll have to plug it if it's not to be visible!

John.

Edited By RJW on 23/08/2013 08:11:44

Simon From what I gather you started depthing the train from the winding hole The usual way is to start at the centre and work up and down Prick punch each position then drill That way you don't use the cone The only time I use a cone centre is on repairs

Roy

Edited By roy entwistle on 24/08/2013 08:41:18