Elimination of Bb/Bb Thumb Lever/Key Action Differential

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flutego12
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Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by flutego12 »

Dear Fluteland

This is my first case with a mistimed Bb/Bb action and I'm hoping I can confirm the approach to tackling this.

This used student flute came in for its first anniversary service.

"AS IS"
A quick visual check shows the pads are largely neatly & "relatively" evenly flush across the cups.
Regulation appear to be spot on APART FROM THE Bb thumblever /Bb key action - the Bb key lags the Bb thumb lever by a 0.6mm differential (when Bb thumb lever is pressed fully).
Cigarette paper check shows most seals are tight with several vulnerable spots with light seal.

WHAT I DID
Usually I start regulating/ shimming from the bottom (D) up (Bb), but with this Bb/Bb differential problem, I regulated it by shiming the Bb key. This however caused it to throw most of the downstream regulation and seals out of whack which needed full adjustment.

[A thought came that perhaps I should just find the regulation screw but I don't believe there is one. Hence the shim. As most keys were flush in the cup, the shim then raised the Bb pad to peep out of the pad cup. ]
I then proceeded to re-regulate and shim the rest of the key mechanisms downstream.



Thank you.
FluteTwelve
Last edited by flutego12 on Mon May 19, 2014 1:03 am, edited 1 time in total.
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fluteguy18
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by fluteguy18 »

Flex the lever.

mirwa
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by mirwa »

There is nothing wrong with a pad being prominent above the keycup, when I repad a flute, my goal is for 0.015" projection of pad surface above keycup edge, this IMO gives best intonation and response, to achieve this, I use various thickness's of pads and or modification of the approach geometry of the key.

Key height is achieved by modifying the foot of each key

Steve

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flutego12
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by flutego12 »

fluteguy18 wrote:Flex the lever.
That would be most efficient - everything else played almost nicely.
At which point would you flex it?
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flutego12
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by flutego12 »

mirwa wrote:There is nothing wrong with a pad being prominent above the keycup, when I repad a flute, my goal is for 0.015" projection of pad surface above keycup edge, this IMO gives best intonation and response, to achieve this, I use various thickness's of pads and or modification of the approach geometry of the key.

Key height is achieved by modifying the foot of each key

Steve
Thanks Steve, for clarifying the terminology and difference between the two.
I'm just thinking that they should all sit at the same projection rather than just three. Because all things being equal, perhaps flexing the lever is not a bad solution, then shim all the pads equally to achieve the same projection.
flutego12 wrote:
fluteguy18 wrote:Flex the lever.
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fluteguy18
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by fluteguy18 »

When I posted my response I was assuming that all padding had been completed. Things need to be done in order. All pads must have protrusion set and must be sealing before you go about regulating anything. I was assuming by 'differential' you meant that it was not closing by the indicated amount.

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flutego12
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by flutego12 »

fluteguy18 wrote:When I posted my response I was assuming that all padding had been completed. Things need to be done in order. All pads must have protrusion set and must be sealing before you go about regulating anything. I was assuming by 'differential' you meant that it was not closing by the indicated amount.

omg. you are right. overconfidence and forgetfulness is not a good thing. :oops: :oops: :oops:
hadn't done this in 5 months but it's no excuse. Thank you for the apt reminder.
from now I must always have chronological checklist in front of me.
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fluteguy18
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by fluteguy18 »

Keeping a list is a good idea until things become habit. Here are basically the rules that I think of and the order in which I approach things:

1. Is it clean? There is no point in doing further work if it is not clean. Dirt and grime can cause damage as you work on the instrument.
2. Does the body seal by itself and has all body work been done? All dents need to be removed, all solder work done, all joints fitted, bore polished, and the body checked to see that it is sealing by itself.
3. Do all of the keys function mechanically without problem and without lubrication? If the keys are working properly, they should function smoothly without oil. This helps reveal small mechanical problems. Oiling only serves to make things even smoother, protect against excess wear, and against corrosion.
4. Do all of the pads seal? If they don't seal, it won't play.
5. Are all regulations correct? If the keys aren't sealing at the same time, it won't play.
6. Are all points of lost motion (or lack thereof) adjusted correctly? On flute, having lost motion is a bad thing.
7. Is it now lubricated? Make sure it's oiled before you finish.
8. Have you cleaned it again? Customers don't like getting a dirty instrument.

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pied_piper
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by pied_piper »

FG12 - Here's a couple of links that you may find useful. The first is a guide to a complete student flute overhaul. It was written by Lars Kirmser and he has shared it on the Yahoo Musical Instrument Repair group, so I don't think he will mind it being re-shared here. This sort of takes FG18's outline to the next level...
https://www.dropbox.com/s/njkjv7f3i1itd ... erhaul.pdf

The second is a link to a doctoral dissertation that was written about flute repair. It has lots of good information about flute repair, but it is written as a guide for a professional flutist rather than a repair tech. It is not comprehensive for all repairs, but it can serve as a good all around basic repair guide. Hey, it's FREE - what you you want for nothing? :lol:
https://etd.ohiolink.edu/ap/10?0::NO:10 ... UBID:66939
"Never give a flute player a screwdriver."
--anonymous--

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flutego12
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Re: Elimination of Bb/Bb Thumb Lever/Key Action Differential

Post by flutego12 »

Thank you sO much. I honestly LOVE you guys! :wink:

Thanks f18 for the checklist and pp for upping the checklist to a whole nuther level. I believe you have sent the links to me before and I had devoured the material every bit of it but that was last year, and I had become a little over confident whilst forgetfulness encroached a little.

And giving honour where it's due, thanks for your generous knowledge sharing, I couldn't have done this without you.
The money that is generated from my refurbishment/ repairs project, a sizeable portion goes in to support theA21campaign. It's been a slow start but since April last year you have helped me raise $X amt from basic servicing alone. I really have you guys to thank without whom it would not have been possible, esp PiedPiper Bob and mirwa Steve, and fluteguy18, including a few others, thundergirl ++. You may not know it but your generous skill sharing and mentoring have given me the tools to generate the funds toward stamping out global human trafficking, the work initially focused in the EU but now also in Asia. You have unknowingly helped educate (for prevention), rescue, rehabilitate, retrain countless girls who have been tricked from poverty into slavery, but who now being restored to have a HOPE and a future. So, thank you. :) :D

You my dear fellows, are priceless!
flutist with a screwdriver

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