First bushing attempt

[Stevelp]

Hi everyone, I hope this message finds you well.  I am currently attempting my first re bushing of a clock plate.  I have been using the KWM reamers along with Bergeon bushings in the KWM sizes.  I have to say this system seems to work quite well, as this is the first time I am doing this and so far so good.  The question I have is in regards to the height of the bushing.  The plate I am bushing is just over 1mm, and the bushings sizes I will have to use are 1.4mm and 1.9mm in height.  So my question is, do I need to shorten the bushings to plate height after installation, or is there an acceptable maximum height above plate height?

[watchweasol]

 When bushings such as yours are thicker than the plate they will need to be filed down to plate thickness and then an oil sink cut.  Ideally with bushing plated you should not be able to tell when its finished that it has been bushed at all. Once done polish the plates.

The old fasioned method was to use a bulls foot file but if you protect the surrounding area and are careful it should be ok.

[Stevelp]

Thanks for the reply watchweasol!  Thanks for confirming what I thought would be the correct practice.  I've never seen a bulls foot file but the concept is excellent!  I may have to attempt to make one at some point.  Another question I have is I see some people recommending "setting" the bushing by peening it.  Is this a necessary step?   

[nickelsilver]

I personally hate when bushings stick out of the plate. I don't mind if they are visible, but they should be flush. Two of my favorite clock brands to work on, Le Castel and Zenith, put bushings in all locations at the factory, nice bronze (Zenith), or bronze or teflon- set in bronze (Le Castel). I just replaced two bushings in a Zenith today, made from beryllium copper, cut to match the originals. Zenith has massive oil sinks and on the arbor side they are cut so a round surface meets the shoulder. Small detail to reduce friction.

 

Nothing wrong with commercial bushings, but yes, trim them to the plate thickness.  Some file them intalled, but even if a master of the file it's pretty much 100% sure you'll file the plate a bit. If a mid 20th century German movement, no huge issue, they are rough to begin with. But on a nice movement, it's unacceptable (personally also for crappy movements).

 

If you have a lathe it's quick and easy to adjust a bushing height. Making them is just a little more time...

 

If you don't, find a piece of metal or even plastic the right thickness, drill and stick your bushing in, file to height, and start saving for a lathe!

[watchweasol]

Setting the bush using a bearing or round punch is usually not required if the bush is fitted in tight, they are friction fitted. the recomended practise if fitting by hand is to broach from the inside of the plate as the broaches are tapered. When the bush is pressed in from the rear the tapertightens down on the bush and it will dnot move when broaching the bearing surface to fit the pivot.

[nickelsilver]

18 hours ago, Stevelp said:

Thanks for the reply watchweasol!  Thanks for confirming what I thought would be the correct practice.  I've never seen a bulls foot file but the concept is excellent!  I may have to attempt to make one at some point.  Another question I have is I see some people recommending "setting" the bushing by peening it.  Is this a necessary step?   

I've known some who make their bushings from standard brass bar stock, and drill the plate with the corresponding same size drill. Then with plate on a solid steel block, bushing in place, whack it with a round punch and hammer to expand the bush and form the oil sink at the same time- and it hardens the brass. I've tried it and it works, but I much prefer friction fitting.

 

 

[clockboy]

I have found it easier to reduce the height before installing the bushing into the plate. For this reason I try to purchase the correct height bushing. If the purchased bushing does not have a oil sink then I fit a bushing just a little thicker than the plate and reduce it down while creating the oil sink which helps hide the new bushing. 

[transporter]

I’m very lucky in having the bergeon system for bushing can’t complain at all but I do choose their bronze bushes over the brass ones.

i have in the past had long bushes and was taught by my mentor to part fit the bushes if too long and file them down to size whilst still poking out of the plate this reduces the risk of marking the plate.

then push the bush in to seat correctly, also buy some rose cutters as these are brilliant and doing the job.

[rodabod]

I noticed nobody mentioned using rose-cutters here. That's what Bergeon supply in their big bushing tool kit. I quite like them - handy for trimming their off-the-shelf bushes and it does actually give a nice finish. Not what I usually use, but worth mentioning nonetheless.

[transporter]

7 hours ago, rodabod said:

I noticed nobody mentioned using rose-cutters here. That's what Bergeon supply in their big bushing tool kit. I quite like them - handy for trimming their off-the-shelf bushes and it does actually give a nice finish. Not what I usually use, but worth mentioning nonetheless.

Yes they are very good, I’m in the process of purchasing a couple now as I’ve had to use a 3mm bush in a 1.75mm plate. 
I’ve used them before ( mentors ) and they are excellent and negate the risk of scratching the plate with file marks.