Leveling rolled tone holes

[pied_piper]

I have to second most of Joe's comments. The mandrel and ball technique should be reserved for badly damaged tone holes. Leveling undamaged tone holes is more about finesse than brute strength. It's really the skill that counts more than the tool. Tools are great and necessary but the repair tech has to know which tools are appropriate for different situations. In unskilled hands, a tool can often do more damage than good.

[fluteguy18]

When are we going to get a 'Like' button around here? I'm desperately wanting to use it right now...

[mirwa]

Well, it appears I am in the minority, but even so I would not change my process.

Joe, very surprised you are of the school of levelling a tone hole via an abrasive is better than burnishing the internal edge of a drawn hole

When levelling a tone hole via abrasive process for anyone, please consider the thickness of the metal, most flutes have a wall thickness of around 19 thou thick, then draw and roll that metal and the tip of the tone hole (the area you are about to cut), could be as little as 8 thou, that is A4 paper folded in half, before you start filing

Steve

[HMannfan]

It is obvious to me that the flute that I am working on has NEVER had its tone holes leveled and it is over 30 yrs old. Granted, I cannot slip a a shim thicker than 2 thou. between the tone hole in my picture above and the plug gauge I'm using, so it's not out of level very much but enough to make fitting a Lucien Deluxe pad without partial shims impossible.

Steve, respectfully, 8 thou. is enough to drive a Mack truck through, so it seems there would be room enough to level these with an abrasive. How much out of level are we typically talking about?

fluteguy 18, I'm curious at your teacher's response to your objections to the mandrel and ball technique especially as he was presenting it as a normal and acceptable method. What alternative did he suggest? Regarding the tool you suggest using to "roll the surface of the tone hole downward", does it actually roll the tone hole further or simply compress it. I have my doubts that it would actually roll the tone hole more without supporting the inner surface of the tone hole chimney which would require precisely milled plugs for every tone hole on every different flute. Did you make this tool during the flute repair portion of your classes, or did you purchase it?

This has been an interesting thread! There are divergent opinions on leveling rolled tone holes each of which has their supporting arguments for what I initially assumed would be a consensus methodology.

Thank you all for your directions and opinions.

Mark

[JButky]

Well, it appears I am in the minority, but even so I would not change my process.

Joe, very surprised you are of the school of levelling a tone hole via an abrasive is better than burnishing the internal edge of a drawn hole

When levelling a tone hole via abrasive process for anyone, please consider the thickness of the metal, most flutes have a wall thickness of around 19 thou thick, then draw and roll that metal and the tip of the tone hole (the area you are about to cut), could be as little as 8 thou, that is A4 paper folded in half, before you start filing

Steve

Oh I most certainly have. I've purposedly file through tone holes of all different materials just to see how much it takes to actually do it. You have to know where the endpoint are and what is acceptable. I've taken filed tone holes and subjected them to hammering to get the rim to fail. I am quite familiar with the limits of abrasive levelled tone holes enough to know that most leveling of this type is perfectly fine unless a tone hole is really bad, in which case different methods must be used. One must remember that a rolled thickness is pretty structurally strong. I've tested a thouroughly thinned rim by putting a piece of metal between a tone hole and keycup and pressing as hard as I can to get it to fail. They are stronger than one might think.

Like all things there are limits. You just have to be trained well enough to know what they are. There are all sorts of ways to fix a non level tone hole that various techs are comfortable with. As long as the tech has a level of experience and mastery with their method, so be it. With every method there are undesirable tradeoffs. I prefer for a variety of reasons to keep my body tube and tone hole wall chimneys undistorted and focus on the rim itself.

[mirwa]

Fair enough joe, I have levelled tone holes with abrasives before as well, just not my preferred method, too many times I have seen flutes come in with lever marks on the tone hole edges, usually IMO because the rim is no longer structurally as sound as it was previously.

[fluteguy18]

fluteguy 18, I'm curious at your teacher's response to your objections to the mandrel and ball technique especially as he was presenting it as a normal and acceptable method. What alternative did he suggest? Regarding the tool you suggest using to "roll the surface of the tone hole downward", does it actually roll the tone hole further or simply compress it. I have my doubts that it would actually roll the tone hole more without supporting the inner surface of the tone hole chimney which would require precisely milled plugs for every tone hole on every different flute. Did you make this tool during the flute repair portion of your classes, or did you purchase it?

You have to understand that Lucas (my teacher) has an odd sense of humor and likes having fun at the expense of others. Nothing mean, but definitely a sarcastic personality. He did not suggest any alternative because in his mind it truly was an acceptable method. That being said he was approaching it from the perspective of a teacher who is teaching students where the vast majority will only rarely work on something better than a student/lower intermediate flute. He and I would often discuss other methods in private because my career goals were to work on higher end instruments. On 'better' instruments the manufacturer usually takes more time to finish the roll of the tonehole to get it closer to being flat. In those cases, rolling the tonehole or filing seems to be an easier and IMO a more appropriate approach. One the really high end instruments the toneholes are often soldered and filing is the only way to level them.

As for the way the tool works, it's hard to explain. It does actually roll the tonehole, but you have to have an understanding of how metal moves when it is being worked. Basically... once metal starts moving in a direction, it keeps moving in that direction unless something changes it. Toneholes are rolled by a flat disk being pushed down onto the tonehole. The tool does almost exactly the same thing that the machines in the factory do: apply downward pressure. Because the metal was already splaying outward, it keeps rolling in the same direction. It's kind of like rolling up a mat. Once you start rolling it, as long as the force stays in the same direction, it won't suddenly wrinkle or bunch up. It keeps rolling.

As for the tool... I do not own one, but they are readily available from places like Allied and Ferrees.

[HMannfan]

fluteguy 18:

Thank you for your response and the explanation. It was thoroughly understandable. I have not seen the mentioned tool on Ferree's, and I do not have access to Allied yet (I haven't felt the need).

I bought the flute tone hole leveler from Ferree's and tried it out today. It worked perfectly well. It has a diamond encrusted surface and will remove only a very small amount of material at a time. Since I didn't need to remove much material it worked fairly quickly and easily. Now I need to re-profile the tone hole edges inside and out. I don't have Joe's experience to enable me to do this with a head joint scraper, so I'll devise another way. Joe, as well as being a very fine repairman, is obviously very creative and resourceful and a good example to us all in that respect.

JLSmith sells a set of special tools for this procedure, but they cost more than I can afford at this minute. My repair friend at Bellwood Violin and Recorder should be able to help me with this project.

I look forward to seeing a new posting on your site about your experiences and specifically with repairing flutes. Continued well wishes during your training and my thanks.

Mark

[mirwa]

Adam, you should not assume that more expensive flutes means they have taken longer in doing things like rolling the edges, that is incorrect.

To this end, you will not know what works for you until you do it for a living, Joe and myself have 10s of thousands of instruments under our belts, and we both do things differently (sometimes)

When the first Muramatsu crosses your bench or high end haynes, lets see which approach you take then, as remember if you damage it or get it wrong you pay for it, being over confident with tone hole filing may bring you undone, I speak from experience, I have seen many flutes done from other repairers where they have overfiled the tone holes, and the customer has brought it to me for correction, my bill in this situation has come close to 1000 dollars to repair some over zealous repairers approach, and I guarantee you that bill was forwarded back to the previous repairer.

As far as getting to work on high end instruments, that usually only ever comes about from word of mouth, from doing years and years of grunt work on student models, learning to prefect your skills.



To this end, Im going to measure a flute on monday when I go back to work in regards to wall distortions, and see what I come up with, joe has got me intrigued. I own a 3d laser scanner, accurate to 0.0005", so Ill laser scan a flute in with a low tone hole, burnish it and laser scan it again, to see what difference has happened within the tube and or if that difference is within the design constraints also measured at other locations where the body has been drawn

Steve

[fluteguy18]

Mirwa-

I actually graduated in May and currently work on flutes and double reeds for a living. True, I don't have as much experience as I would like but that will be quickly remedied. I have already been in the situation you described, and after assessing the problem and remedies, I took appropriate action. Have I messed up yet? Not quite. Will I in the future? Undoubtedly. And in those moments I will continue to learn (as should we all). But I'll remember your encouragement and vote of confidence in the future. It's greatly appreciated to know that technicians openly foster such warm and supportive rapport amongst colleagues (even young ones).

[JButky]

To this end, Im going to measure a flute on monday when I go back to work in regards to wall distortions, and see what I come up with, joe has got me intrigued. I own a 3d laser scanner, accurate to 0.0005", so Ill laser scan a flute in with a low tone hole, burnish it and laser scan it again, to see what difference has happened within the tube and or if that difference is within the design constraints also measured at other locations where the body has been drawn

Steve

Nice, I look forward to your report...

Most of the distortions of tone holes chimneys I've seen were caused by the washer and screw method. I am aware of one person who uses a flat piece of plexiglass to tap down the high spots. I tried that and it just didn't work well for me. It's OK for people to have different techniques, just so long as they understand what they are doing and have developed the proper technique to get the job done...

[mirwa]

Yep, I have tried Gordon's method as well, did not work for me either, not that I doubt it works for Gordon.

[HMannfan]

Steve,

I, too, look forward to hearing about your results. I visited your website and was extremely impressed by the tools you have amassed particularly noting the CNC machines and 3d laser scanner.

Mark

[fluteguy18]

I had a few extra minutes at work today and decided to grab a flute out of the graveyard box just to see how far I would have to file in order to get through the tonehole rim. While I'm sure that it is certainly possible to file too far, my specific venture to do so was unsuccessful. I settled on a 600 grit diamond abrasive and went to work. 45 minutes later and a lot of valve oil on my apron and I still hadn't gotten through the tonehole. I thought that the grit had loaded with metal, but after a cleaning in the ultrasonic and inspecting with an eye loupe, I discovered that I had worn out the file instead. There's a ring of smooth steel all the way around the file.

There went $40...

[mirwa]

I settled on a 600 grit diamond abrasive and went to work. 45 minutes later and a lot of valve oil on my apron and I still hadn't gotten through the tonehole.

That does not seem to equate correctly