Bushing larger diameter - no Broach available

[Garfield]

What would be the plan for inserting a bushing for something such as a barrel pivot when there is no broach available for the size.

The size of bush I need to install is 10mm OD, I'd have gone for something like 9.9mm perhaps a tad larger such as 9.95mm but these sizes seem to be no longer available. I could probably go a bit smaller than 10mm, the smallest pivot on the barrels I have is 4.8mm (rear) but the largest is 5.7 (front), the smallest OD below 10mm is 8mm - is 1mm of bush going to work once I open up the pilot hole to say 5.8mm - I'd prefer to use parallel broaches / reamers. The bushes are tapered on the OD. (From Cousins UK > Barrell Arbour Bushes

Has anyone had any luck with adjustable hand reamers ?

I'm concerned about the hole shape since a drill or reamer won't really find the centre.

 

[wow]

I do those in my mill but it could be mounted in a lathe with a three jaw chuck and center would not be a problem.

 

[RJSoftware]

What would be the plan for inserting a bushing for something such as a barrel pivot when there is no broach available for the size.

The size of bush I need to install is 10mm OD, I'd have gone for something like 9.9mm perhaps a tad larger such as 9.95mm but these sizes seem to be no longer available. I could probably go a bit smaller than 10mm, the smallest pivot on the barrels I have is 4.8mm (rear) but the largest is 5.7 (front), the smallest OD below 10mm is 8mm - is 1mm of bush going to work once I open up the pilot hole to say 5.8mm - I'd prefer to use parallel broaches / reamers. The bushes are tapered on the OD. (From Cousins UK > Barrell Arbour Bushes

Has anyone had any luck with adjustable hand reamers ?

I'm concerned about the hole shape since a drill or reamer won't really find the centre.

do yourself a favor, get aused movement from eBay

 

[gmorse]

Hi Garfield,

Industrial suppliers such as Drill Service Ltd can supply reamers in a wide variety of sizes and types, (some of which are pretty costly), but you still have the problem of accurately locating the true centre so that the arbor runs upright. Using the other plate as a guide, if the hole isn't so worn, is a possible way; ask Jerry Kieffer again!

Are you talking about the holes in the plates or those in the barrel itself? Clearly, mounting a barrel in the lathe is much easier than mounting the whole plate, so really the ideal solution here is a mill. From what I've seen of dedicated bushing tools, they all suffer to a greater or lesser extent from issues of runout and/or lack of rigidity, plus they're becoming very expensive.

Regards,

Graham

 

[Garfield]

The holes in the plates, one is distinctly not round, the front plate is significantly worse than the rear. I have bought a number of 'spares' and all are in various states of abuse. This is another motivator to finally get a machine / machines as I'm now running into challenges where I know I can fix but lack the means. I plan in this particular case to bush both back and front plates at the same time with them clamped together at least for the bushing hole, the bushes I planned to use have pilot holes already.

In fact if I had the machines I wouldn't even buy bushes I would turn my own.

 

[Willie X]

How bout a photo? If it's a clock, even a big one, the bushing work should be doable. You can buy big flanged bushing for huge clocks. Willie X

 

[Mike Phelan]

Yeah - what diameter is the worn hole on the plate where your arbor lives?

 

[Garfield]

Sizes described in original post, clock movement is currently assembled to stop parts going missing now that I know what it requires, it would run I think but there's a lot of play, the holes in the front plate are both worn oval, presumably because when wound the weight is all at the front, looks like it hasn't been allowed to run down far. As a result the back plate hole isn't concentric as the barrel has been running with a front down angle.I know what isa available to buy but fitting the bushes accurately is a different story.

 

[Willie X]

Regular Bergeon bushings and reamers go up to 8.5mm OD, with a 5 or 6.5mm hole ...

A 10 page description will never as good as a single photo. Ha, Willie X

 

[Jerry Kieffer]

The holes in the plates, one is distinctly not round, the front plate is significantly worse than the rear. I have bought a number of 'spares' and all are in various states of abuse. This is another motivator to finally get a machine / machines as I'm now running into challenges where I know I can fix but lack the means. I plan in this particular case to bush both back and front plates at the same time with them clamped together at least for the bushing hole, the bushes I planned to use have pilot holes already.

In fact if I had the machines I wouldn't even buy bushes I would turn my own.

As you have concluded, when properly equipped the solution would be quick and simple.

However, as a one time one off solution, it is possible to do a accurate repair with a little extra effort and creativity.

If I were in your shoes not knowing what tools you have at your disposal, I would probably repair as follows.

(1) Find a piece of scrap metal material (steel, brass, aluminum or whatever) and drill a 10mm hole in it if using a 10mm bushing or whatever size using. Enlarged hole in the photo is for illustration only and was handy.

(2) Center the hole in scrap on the original winding arbor hole and clamp in place per attached photo. You can now drill the 10mm hole in the plate guided by the work piece and be assured that the hole will be where intended. After drilling " lightly Chamfer" each side of the hole.

(3) Turn the bushing on edge on a flat surface with a course file on top and roll a knurl on the edge. This will give some friction fit for the next procedure.

(4) Install the bushing with an even amount exposed on both sides of the plate. Then squeeze the bushing tightly in a large vise causing the bushing to expand into the light chamfer locking it in place from both sides. The bushing can now be dressed flush with the plate on both sides.

Jerry Kieffer

 

[Garfield]

Much appreciated Jerry - a simple jig - seems obvious now but just wasn't thinking that way, I have a pretty substantial press at my disposal used for automotive stuff and a couple of serious engineers vices too, should be able to use some shims / penny washers as spacers to get them centred - the plates are 3mm thick, the bushes 4mm.

I shall drill both plates together, but bush seperately, I may put the plates back to back again once the bushes are flatted and then put a 4.5mm drill through the pilot hole of one bush and through the other then I'll hand finish to suit the worn spinde / pivots. Pity there isn't a clockmakers version of a line boring tool ....

Just out of interest has anyone ever filled holes then redrilled ? - I do have a pretty good TIG setup

 

[kinsler33]

The holes in the plates, one is distinctly not round, the front plate is significantly worse than the rear. I have bought a number of 'spares' and all are in various states of abuse. This is another motivator to finally get a machine / machines as I'm now running into challenges where I know I can fix but lack the means. I plan in this particular case to bush both back and front plates at the same time with them clamped together at least for the bushing hole, the bushes I planned to use have pilot holes already.

In fact if I had the machines I wouldn't even buy bushes I would turn my own.

An inexpensive drill press will do almost all of the work you'll run into, but it won't make bushings. But you can make almost any bushing with bushing wire

 

[Willie X]

Do you know how to prep the drill bits in order to drill brass? Unprepared drills can result in a disaster.

Shimey Step had photos of big bushings he was installing a few years back. His method was similar to Jerry's but he was using a flanged bushing with a chamfer on the inside of the plate and he peened the slightly protruding edge of the bushing into the inside chamfer. You can often leave the inside slightly proud on a clock that had excessive endplay at the start.

Willie X

 

[Mike Phelan]

For twist drills I have two sets - one for brass has the ends ground flat = difficult to describe but I'm sure that this has appeared in a few posts on here.
FWIW There are broaches of all sizes and taper reamers likewise.

 

[Willie X]

The best tool I've found to 'prepare' a twist drill for brass is a Dremel with a .020" cut-off wheel. The side of the wheel is held in plane with the center-line of the drill bit. The little flat you make will be perpendicular to the workpiece when the drill is in use.

You can also use a 'slip'. These little stones are often used to sharpen fish hooks and are rounded on one side and flat on the other. A diamond fingernail file works pretty well also.

The Dremel tool is fast. So, on a larger bit, you can use it first and true up your work with a slip, etc. which is more accurate.

Clamp your work good and run the drill at a moderate speed with slow feed.

Willie X

 

[Garfield]

I'm aware of the tendency for brass to grab machine tools / drills, I don't have a drill press either in fact I have very few 'fixed' power tools hence the thread I started elsewhere since it is time that I did have them.

As for broaches of all sizes being available not so much any more at least not from watch and clock suppliers, anything beyond 7 or 8mm is not something I have found. From engineering sources reamers of all sizes yes including adjustable reamers. If I had the machinery I'd make my own broach from rod stock - but I don't.

I am intrigued on the bushing wire - how would I bush a clock plate with bushing wire for a 5mm pivot. I could fill the holes easily with rod but then I lose the centres - but a jig could be made to locate the centres I suppose - just being lazy I guess.

 

[Willie X]

How bout a photo ... you mention "barrel pivot". Is that a bushing in spring barrel or a bushing in the plate Are the holes plain, or already bushed with a stepped brushing? Lots of basic questions are unanswered at this point.

Also, some kind of machine, at least a drill press will be necessary.

Also again, if the clock is dear, or valuable, it would be best to farm this job out.

Have you described the problem you are having with the clock? I might have missed it.

After16 hits, I don't think anyone knows what you have there, or the problem you are haveing?

Willie X

 

[Garfield]

Picture really wouldn't show it - think of it this way - if you hold the shaft where the key goes for winding you can move it up and down by at least 2mm, hard to show in a picture, the barrel does not run at right angles to the plates, I'll see if I can find a way to show but I'm not tearing the movement down again until I'm ready to do something with it. It wasn't particularly expensive but to me I still believe in the 'first do no harm' but farm it out nope I don't learn if others do and those others must have learned some place so I've bought some brass sheet to practice on, in fact I bought enough to make completely new plates as practice.

I am looking at a Sherline milling machine currently.

 

[kinsler33]

I'm aware of the tendency for brass to grab machine tools / drills, I don't have a drill press either in fact I have very few 'fixed' power tools hence the thread I started elsewhere since it is time that I did have them.

As for broaches of all sizes being available not so much any more at least not from watch and clock suppliers, anything beyond 7 or 8mm is not something I have found. From engineering sources reamers of all sizes yes including adjustable reamers. If I had the machinery I'd make my own broach from rod stock - but I don't.

I am intrigued on the bushing wire - how would I bush a clock plate with bushing wire for a 5mm pivot. I could fill the holes easily with rod but then I lose the centres - but a jig could be made to locate the centres I suppose - just being lazy I guess.

I think bushing wire is still available from Timesavers, even if they don't know quite what it is. You drill or ream the existing hole out to roughly fit the OD of the bushing wire. Then, using a jeweler's saw and more skill than I generally have these days, slice off a piece of bushing wire abou as long as the plate thickness. Place the plate on your anvil and the bushing wire slice in the hole. Vigorously apply the hammer to rivet the slice into the hole. This'll mess up the center hole but a broach will clear it out. Broach out the hole to fit the pivot, file off the bushing flush with the plate, and you're done. A countersink will make an oil sink if you believe these actually do anything. This bushing will never fall out.
Note that the above was standard operating procedure until press-in bushings appeared around 1960, and it still makes a better bushing.

 

[Garfield]

an 8mm or 10mm hole is hardly wire but do they still call it wire. The only reason I don't use brass rod is that the bushings come with centred pilot already. It is the creation of the larger holes accurately enough for the press fit of bushes or rod that is the challenge, I was hoping there were hand tool options but that is just making a simple task way harder than necessary.

 

[RJSoftware]

I literally went through this 2 clock acquisitions ago. I just found this guy on ebay who sold various main spring barrels. I was pleasantly surprised with the quality. Even the main spring was in better cleaner shape. All for about $15. Soo nice. My original barrel was ovaled, both lid and bottom bushing slack. I was glad just to get rid of it.

When the barrel bushing s are not tight the barrel will angle like that. The 2mm key slop is plate bushing. I would hold off doing plate bushing till after I installed new barrel.

One trick for large bushing. Once new brass installed, drill smaller hole. Taper open a touch, then force arbor through. This can make a tight fit. The trick is how much to taper vs how much to force. Twisting helps. There is a sweet spot where when the arbor just begins penetration as brass compliance felt.

 

[kinsler33]

The best tool I've found to 'prepare' a twist drill for brass is a Dremel with a .020" cut-off wheel. The side of the wheel is held in plane with the center-line of the drill bit. The little flat you make will be perpendicular to the workpiece when the drill is in use.

You can also use a 'slip'. These little stones are often used to sharpen fish hooks and are rounded on one side and flat on the other. A diamond fingernail file works pretty well also.

The Dremel tool is fast. So, on a larger bit, you can use it first and true up your work with a slip, etc. which is more accurate.

Clamp your work good and run the drill at a moderate speed with slow feed.

Willie X

I've modified several drill bits by hand with a diamond file. Despite my standards of craftsmanship they drill brass neatly and without drama. For a elegant finishing touch each modified bit is slathered with red nail polish on the fluted portion where it won't wear off.

M Kinsler

 

[Garfield]

I've bought some additional bushes so I can play some I shall try a number of options. I have the chance of a Sherline lathe but right now I think a milling machine would be more useful.

Red nail varnish - was it missed by the owner ?

 

[kinsler33]

I've bought some additional bushes so I can play some I shall try a number of options. I have the chance of a Sherline lathe but right now I think a milling machine would be more useful.

Red nail varnish - was it missed by the owner ?

Nope. I bought my own. I have a jar filled with various colors, ostensibly for touching up cuckoo clock figures.