In a somewhat lengthy previous discussion

Staff replaceing

about the use of a #50 staff removal tool was questioned by some for damage to the balance wheel. I tried to explain how this staff remover worked without doing damage to the balance wheel, but to little or no avail.

Below is what is the result when I use a #50 on an Illinois 9th model Bunn special. The perfect rivet ring removed from the staff by the #50 remover is a little small for pierced ears unless you know a tiny fairy floating around somewhere.

Dave,

Both Elgin and Waltham recognized the potential for harming the critical hole dimension and shape in the balance arm utilizing this tool. Your picture of the ring sheared off does NOT preclude what is left of the rivet tearing thru the hole on its way out the other side. I see this time and again where after a couple of staff replacements a new staff will no longer friction fit into the hole for riveting. I stand by my statement that just because a tool is made to do a job, doesn't mean the tool is a good tool OR that it does the job better than another method. By cutting the hub away from the opposite side of the rivet, all danger of damage to the hole is removed PROVIDING the person doing the cutting knows what they are doing. There are usually several methods to accomplishing a task and usually some methods are better than others. I respectfully submit that the tried and true method of cutting is the best and ONLY way to avoid the chance of distorting the hole...again providing the person doing it knows what they are doing and after all don't we want to preserve these parts for future generations? The number 50 staff removal tool will not help in this respect in my opinion.

one question would this tool be safe for none riveted or just pressed balance staff's. t.i.a. george

Roger, I apologize for any offense you take with this post. I have no argument with you.

George, press fit staffs need to be carefully removed with the regular stumps and stakes available with most staking sets. The issue in removal is to make sure the balance wheel staff hub (an extra parts in most cases) is supported when the old staff is tapped out of that hub, otherwise you will knock out the staff and hub.

installing a press fit staff is explained by Fried:

Thanks I will look that up..george

Dave,

No apology necessary. I was not offended. We both have strong opinions regarding this tool and that has created a good discussion.

Kind Regards,
Roger

I'm confused.

I've read the posts thoroughly and agree with Roger in that damage will occur to the balance wheel arm unless the rivet portion of the staff is completely removed. Roger's approach is to mill off the rivet burr while chucked in the lathe.

Having never seen the L&R #50 in action, I'm assuming the ring in Dave's picture is what's left of the rivet burr after it's sheared off. Wouldn't his method also protect the balance arm from being reamed out?

I still agree with Roger on this one David, but I think it would be an interesting exercise in conducting an experiment with a balance wheel and a small hand full of staffs using the K & D tool. Fitting and then punching a half a dozen staffs with the same wheel, taking measurements after evry removal to see what changes occur with regard to hole size. I know this would be an expensive proposition but I have a few kits some with a large lot of staffs so when I get a little time (always at a premium) I might have a go at it and record the results for everyone.

So let say after 6 staffs the hole in arm get
bigger.
Now how many staffs have been change in watch life
since roll out of production(we might never know since they are older them most of us)
So if the hole is bigger I will order new balance wheel install new staff problem solve.
Lathe=few hundreds $ and skills you will have to have.
#50 remover fewer skills and $50 in equipment
just my point.
I will love to have and use the lathe since I have the skills over 25 years in machine shop from manual lathe to 5 axis CNC mill.
With no lathe and no room to put I will us the #50 till I get lathe and find room .
Just my one cent.
Best regards to Dave and Roger as both are excelet watch makers.

Eric,

The rivet side is not cut, it is the hub side that is cut and then the staff pushed out the side the rivet is on so the rivet never comes thru the hole in the arm. Attached is a picture of the ring that is produced when the staff is cut from the hub side. Once enough material is cut away there is no resistance to simply pushing the staff out toward the rivet end.

Peter,

Replacing the balance also removes the serial number that is engraved on the underside of the balance arm. Most of us would like to preserve parts and keep these serial numbered parts with the original movement.

You might want to go back to the original thread:
Staff Replacing
where Patrick inserted the Waltham explanation of why the proper method is to cut the staff out. Read it carefully. Why would we try to second-guess the people who manufactured the watches???

That part I get, Roger. The peened-over part of the rivet (red arrow) is what you're milling off in the lathe so the staff just pulls back through the balance arm.

Doesn't Dave's method shear off the same part, leaving that tiny hoop he showed in the picture? Or does that #50 thing do something else entirely?

No Eric...It is the opposite side that gets cut. See the picture in Patricks post that Waltham put out. The tool shears the folded over rivet and leaves the ring that Dave shows, but it also leaves the ragged edges tearing along the wall of the hole in the balance arm (IMO, Waltham's opinion and Elgin's opinion). Cutting from the other side, you are going in with the graver to a smaller diameter than where the staff comes thru the arm. You push the staff out with no ragged staff edges coming in contact with the wall portion of the hole.

So you're cutting through the thicker portion that forms the shoulder for the roller table? I got it now; that's a fair amount of hardened steel to cut through.

That is correct Eric, but a sharp graver (I like to use carbide) cuts like butter.

With a precision Jeweler's Lathe like the Cowell offered for $2999.00 on eBay right now, machining out the riveted staff would be easy. In the final round, I side with our top watchmaker who I quote: "When a watchmaker has a bad staff the best option is a new Balance wheel/Staff assembly from the manufacturer".

This is an interesting topic but on the topic of just replacing the balance if it is marked with a serial number I would rather keep it rather than replace it even if the staff needs replacing. Others might feel differently but to me that would be like just swapping the balance cock and all from a parts watchm yes it happens and most of us grumble when it does because it takes something away from the originality of the watch.

The Cowell lathe that Dave shows is not one I would ever use for watchmaking purposes. It may be very nice and well made, but certainly is not made for a watchmaker IMO. This looks like it would be great for a model maker. For those looking for a lathe, my personal opinion is an 8mm WW type which was made by Boley, Levin, and many others. Attachments/accessories for these are plentiful. While you may find a lathe for a few hundred dollars you won't be able to do much of anything with it unless you have a full set of collets and various other accessories. For a nice lathe with a decent assortment of collets and accessories you will probably have to spend at least $1500.

I could never understand why,back when these watches were built,they didn't just make a brass bushing pressed into the balance arms, with it's ID sized so the staff could be either friction fitted or riveted to it, rather than directly to the steel arms.That way, no matter what method you use to get a busted staff out,there would be no chance of hurting the balance itself.The bushing would be a sacrificial link.Doesn't that make sense?Not being a watchmaker myself, I can't think of any reason that couldn't be done.

I almost hate to resurrect this, but I finally got around to taking an old junk wheel and removing the staff using the K&D no. 50 tool. The pictures speak for themselves. The ragged edge tearing thru the balance arm hole will damage the hole. I took a brand new staff after removal and placed the balance over it as if I were going to stake it. There was no friction fit over the staff. Just to be sure, I tried two other staffs and they all fit loosely over the hole in the balance arm. Since we are all interested in preserving these watches for posterity, I see no good reason to try to validate the use of this tool. It is destructive by its very nature.

pic two

pic 3

pic 4

Roger,I have replaced staffs both ways and must observe "tight" fitment of the balance wheel bore to the staff shoulder is "iffy" at best.

In all cases after a test fit, I carefully peen the staff bore with the correct radius tipped stake to assure a well centered, light press fit.

My life has been spent figuring out how to make things work, ranging from Singer Sewing Machines to Space Shuttle Re-entry Tiles, a task in itself. Proving these things WILL NOT work is far easier.

Dave,

You make a very important point that in all cases a light press fit is necessary. Using the correct radius tipped stake is the only way to attempt to bring the hole back to a semblance of originality and I find that I have to do that as well many times when I have cut a staff and then found a loose fit of the replacement staff. I can also almost always predict when this is going to be necessary by observing that the balance has seen prior staff replacement. The evidence may be circumstantial, but I firmly believe that prior use of a staff removal tool such as the K&D no. 50 has caused the hole deformity. I would rather avoid this in the first place instead of having to try and repair the damage after the fact, which is really only a best effort at that point. I don't ever remember having an instance where it looked like I was replacing the staff in a particular balance for the first time, cutting the staff and then having an oversize hole in my balance arm. In the end, each of us must decide for ourselves which method to use and whether we possess the skills and tools necessary for our preference. I have a rather large investment in lathes and microscopes and have garnered the skills to use them so I can perform tasks in what I consider the best way possible. I can appreciate that others may not have that investment and if they want to replace a staff then the only method they can use is a tool like the K&D 50. This discussion sort of reminds me of someone with a nail in the tread of a tire. The quick fix is a plug inserted from the outside of the tire which is what many if not most facilities would do. The correct repair is patching the hole from the inside, but that of course is much more work and much more expensive.