Non compliant bellows

[wes]

Being a bit lazy by nature, I purchased a bellows for a quite nice 20b lach fine fretwork from an Ebay seller by way of co Kerry instead of spending the time to make them myself. They looked well made, robust as I have on a Crabb angle, not the more delicate looking bellows that a good lach usually has. I do think that the robust bellows is more suited to brash Anglo dance style. 

Anyway, I've been fighting these bellows ever since install without progress. The other eve I played for about 15 minutes under my favorite bridge and my hands and forearms were in pain. I've put them in a compression device for weeks, treated them brutally as an excersise spring between the knees with air button full on and nothing helps. What kind of glue was used here?? Regrets for sure, but am hoping someone has an idea to bring this stubborn bellows into compliance as it affects the instrument response greatly.

[Chris Ghent]

Some cheap bellows are made with folded card rather than hinged card. They may break in eventually. 

[Tiposx]

I bought two sets of these (They are presumably from the same source as yours) just over a year ago to fit on english 'tinas. They were a very good price and well made to my request for a seventh fold in very quick time, only 2 weeks.

I noticed that they were quite springy, but definitely made to a high standard with seperate bellows cards. Yours sound much harder work than mine were, perhaps that 7th fold masked it. I felt that they were probably more suited to anglo than e.c. but at around half the prices I had been quoted from other makers.

I sold one of the 'tinas to someone who was very happy with them. I kept the other one and still play it every day. The bellows took a long time to loosen up, in fact they are still much bouncier than I would like. They don't settle in a closed position, and gradually open up a couple of inches. 

However they are much more supple than when new. I noticed a big improvement when I started to stretch several elastic bands lengthwise around the 'tina in between every playing session. I guess it might take another year to really relax them!

I make my own bellows now, and the springiness is designed and built "out" before they are finished.

 

Edited March 13, 2021 by Tiposx
Tipo typo

[Frank Edgley]

Another factor in a good bellows is the depth of the folds. Shallow bellows may have seven or eight folds, but never reach good playability because the folds are too shallow. It's simple geometry.

[Mike Jones]

I have bought two sets of bellows from the same supplier over the last few years, one set fitted to an Anglo and the other to an English. I very much like the quality but they did take some time to break in and I think they suit the Anglo better, even so I'm very happy with them. The instructions for fitting were good too.

[wes]

I think Frank got part of the problem with the folds being too shallow. I measured 1/8th less depth than older bellows on 3 other instruments. The material used for the valley hinges or gluing that hinge cloth without the individual cards being completely flat or just gluing them too tight. I know because I've done the same on my first sets. Ah well, I'll struggle on, thank you all. Sliante!

[ttonon]

On 3/13/2021 at 11:02 AM, Frank Edgley said:

Another factor in a good bellows is the depth of the folds. Shallow bellows may have seven or eight folds, but never reach good playability because the folds are too shallow. It's simple geometry.

Hi Frank, interesting point, and I want to make sure what's going on here, in detail.  I think the depth of folds and the number of folds are independent parameters.  Correct? 

 

It also makes sense to me that a shallow fold will require more force to open than a wider fold, simply because the part of the fold that flexes assumes a greater part of the fold material, resulting in less of a "lever distance" available to the musician, who must then exert more force.

 

In addition, since the force required to bend individual folds is in series with all the other forces associated with the other folds in the bellows, the total force is equal to only one of the forces.  Thus the total force to pull the bellows is only about equal to the force required to open only one of the folds.  This applies to the force required to close the bellows, if the equilibrium position of the bellows is in an open position. 

 

Is that about how you'd sum it up?  Thanks.

 

Tom

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