needle files

[Willow]

Hi hope everyone hope you are all well, just a quick question do i need needle files as well as cutting and polishing broaches when bushing if so are there a certain  size i should be looking for

thanks Paul

[watchweasol]

Hi Willow  as long as you have 5 sided cutting broaches and smoothing broaches you will be ok you will some time need to trim a bush using a bulls foot file (look it up).  I have a full selection of needle files used for a variety of jobs, they are always usefull.

[Willow]

Thanks watchweasol yes i have the broaches will have a look at the bulls file

[rodabod]

I’ve learned something new today!

https://sherline.com/wp-content/uploads/2016/03/tip_070.pdf

Great idea. 
 

Alternatively, use a rose cutter like what is included in the Bergeon bushing sets. And some staking sets, actually. 

[oldhippy]

If you have a lathe you do not need a bulls foot file. Needle of various shapes and cuts  as well as slotting files are always handy to have. I always preferred to turn the bush down to the right size and height without using files, bulls foot file will mark the plate you are bushing. I always made my own bushes.   Sinkers are good to have as well.

[Willow]

thanks everyone for your input

[Orologi67]

The only time i need a needle file is when the pivot hole is extremely worn. 

Say one side of the pivot hole is elongated away from its original center.  I use the round needle file to open up the pivot hole on the unworn side opposite to the elongation.  Thus when i go to center the bushing machine its a bit easier to ream out.

Usually the pivot hole wont need the filing.  This is extreme instances where the hole is so whacked that attempting to ream may shift the plate or break the reamer.

[Willow]

Thanks Orologi67 i will keep that in mind

[oldhippy]

With 5 sided cutting broaches you don't need to file elongated holes, the broach will automatically find the center as long as you use the tool properly.  

[Willow]

Thanks Oldhippy that sounds much easier

[nickelsilver]

I don't necessarily agree that a broach will find the center of a worn hole. With some reamers the tool may well center in the oil sink, which in most cases is concentric with the original pivot hole, but a broach will tend to average over the original center and new center. In the image the outer circle is the oil sink, the black portion is the original hole and the cross the original center. The light blue portion is the worn area, the red circle its center and the magenta circle is the "average center". If we just broach the hole open the broach will tend toward the average center, or perhaps a bit more toward the original hole as it's larger, but will still be off. That the clock ran until its current state of wear, it will almost certainly run and run better than before even with the new "average" center, but it could be better. The upside is if a bushing is put in, even in the semi-wrong location, future wear will be in the bushing, which will be replaced and be in the same location (i.e. you won't be stacking up wear errors).

 

Personally I tend to give a few licks with a file or drift broach to get the hole reasonably centered, but in some cases especially if the wheel or pinion isn't right next to the plate I trust that the oil sink will center my tool.

 

 

[oldhippy]

With a five sided reamer it will work from the original hole and miss the elongated part at first only when it is cutting will it cut the outer which will be the worn part. If you use the right size tool and insert it in the hole you can see it isn't touching the elongated part. 

Looks like we will have to agree to disagree. Stay safe my friend.  

[Willow]

I respect both of your advice as i am doing it on a cheap clock for the first time to see if it will run i  will bow to your experience 

oldhippy and do it your way, thanks to you both

[Orologi67]

5 hours ago, nickelsilver said:

Personally I tend to give a few licks with a file or drift broach to get the hole reasonably centered, but in some cases especially if the wheel or pinion isn't right next to the plate I trust that the oil sink will center my tool.

I can, 9 times out of 10, use the bergeon bushing tool dead center bit to center the hole to be reamed out.  Once the plate is secured in the clamps, the dead center will have a slight gap on the side where the pivot hole is worn.  Then i find the smallest reamer that will fit the hole and i use that to cut only the side that is unworn FIRST by turning the reamer 180 degrees only.  After im confident ive enlarged the hole on the one side i go for a larger reamer that will fit the hole and turn that one 360 degrees until its completely sunk up to the shank of the reamer. Then ream to bushing size.

If the pivot hole is terribly out of shape i file the unworn side first because the reamer has a tendency to snag the edge of the worn part of the pivot hole.

I cant see how a 5 sided reamer will find the original center because to use that type reamer youre working with your hand instead of both plate and reamer being stationary/clamped like the bergeon bushing machine allows.

So i agree with you @nickelsilver

 

 

[nickelsilver]

As I recall OH didn't use a bushing tool (I don't either), and I'm sure he got terrific results from his technique. I can see what you're saying OH about the broach tending to center up in the original hole but will agree to disagree about how well in all cases- but it's not a criticism, more of an observation and a feeling. I come from a background in prototyping of watches and do fall into the trap of being a little too finicky with clocks- haha.

 

One thing we very much agree  on is making bushings as needed and to size- I hate seeing bushings standing 1.5mm out of the plate, especially as sometimes the pivot doesn't even reach the oil sink which has its own set of problems.

[oldhippy]

Try it with a clock depthing tool and you will see what I mean. 

[Willow]

thanks appreciate all your views i have learnt a lot, take care

[Michael1962]

I have an Emco Unimat lathe which I bought and have yet to really use in anger on turning any bushes.

If I turn a bush, how do I ensure that the bush will definitely fit the plate hole correctly after being friction fit? It is quite possible that the bush may not go in far enough or could go to far through the plate. Sorting out the angle to turn is going to be a bit awkward as well. I have a thought about getting the angle of my cutting broaches and then setting the compound slide to the angle and leaving it at that. Going to be a bit of mucking around, but hey-ho.

Sure, you could keep checking the plate hole against the bush as you are turning it, but that still leaves a fair bit of guesswork as to whether the bush is at the correct finished size to be able to be inserted into the hole and to be flush on both sides.

I have seen reference to bull's for files and have had to look them up as I had never heard of them. I agree with @oldhippy that marking the plate with the file would be very easy to do.

I am wondering about riffler files? Another term I had not heard as when I did my time, that just weren't required for anything that I did. I only saw them at a job I recently left.

Would these be an option for finishing a bush to the plate due to the curves built into them?

[oldhippy]

I was very fortunate when I started the workshop was well equipped with loads of needle files and screw slotting files. Suppliers sell a good range so have a look you don't need rough cut ones but smooth. If you buy cheap the cutting edge will soon wear, so buy the best you can afford, you can pick them up in a plastic wallet in a good assortment. Loads normally on ebay but be careful with secondhand they could be worn or clogged up.