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Question About That Tubing


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First of all, Hello. I'm Mark 996 and I'm brand new to this. I inherited a 30 button "Regoletta" Concertina from my grandmother. It looks like new but I noticed that some of the buttons would disappear when pushed. When I took it apart I saw that all the little rubber tubing used to hold the buttons in place was dried and crumbling.

I tried to replace it with clear plastic tubing but it was way too stiff. Do I use surgical rubber tubing? It seems to measure 5mm outside and maybe 3mm inside. I can't be sure. Also would anyone know the approx. worth. There was a Concertina "Regoletta"

With 20 buttons going for $329.00?? Thanks to anyone who can help Mark Occhipinti

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Common Repairs

The 30 button Bastari/Stagis will eventually have a problem with the rubber bushings, or sleeves, holding the buttons to the pad levers. The rubber will eventually get hard and the pad lever will wear a groove in the rubber where it bears on the lever. Thus the buttons will cock in their movement and tend to stick in their holes of the endplate. The first thing to do is to use model airplane fuel tubing rather than surgical tubing for the replacement. I use Aerotrend “Blue Line” silicone (www.aerotrend.com). I have experimented with two sizes of tubing; 3/32” ID (part # 1003,)and 1/8” ID (part # 1005). The 3/32 has an OD of 7/32”, while the 1/8 ID’s is ¼”.

Either size will work, but I have found that the smaller seems to be best. There are some places where there can be a clearance problem with adjacent levers, so the smaller OD has an advantage.

In order to get the best performance from the buttons one must understand the mechanics of the action. When pressing the button it should travel perpendicular to the end plate. However the valve lever moves in an arc, so the attachment of the button to the pad lever must act not only as a hinge, but the attachment to the button shaft must have some flexibility to move slightly along the axis of the lever as well. Otherwise the button would also move in an arc and bind in the endplate. With this in mind the length of the sleeve should be just long enough to hold the button on the lever. Too long a length will hold the button too tightly to the lever and not allow any motion along the lever. It should not be enough to let the button slide on the lever, but shift a little using the flexibility of the tubing. Again, too long a length will compress the tubing limiting that flexibility.

While replacing the sleeves, it may be noticed that some of the lever arms have been bent sideways as a result of the cocking of the buttons. Also, the arms themselves may wobble due to the U bracket holding the axle being too wide. A good quality pair of needlenosed pliers will be necessary to effect the adjustments.

Cheers,

Geo

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Common Repairs

    The 30 button Bastari/Stagis will eventually have a problem with the rubber bushings, or sleeves, holding the buttons to the pad levers.  The rubber will eventually get hard and the pad lever will wear a groove in the rubber where it bears on the lever.  Thus the buttons will cock in their movement and tend to stick in their holes of the endplate. The first thing to do is to use model airplane fuel tubing rather than surgical tubing for the replacement.  I use Aerotrend “Blue Line” silicone (www.aerotrend.com).  I have experimented with two sizes of tubing; 3/32” ID (part # 1003,)and 1/8” ID (part # 1005). The 3/32 has an OD of 7/32”, while the 1/8 ID’s is ¼”.

    Either size will work, but I have found that the smaller seems to be best.  There are some places where there can be a clearance problem with adjacent levers, so the smaller OD has an advantage.

    In order to get the best performance from the buttons one must understand the mechanics of the action.  When pressing the button it should travel perpendicular to the end plate.  However the valve lever moves in an arc, so the attachment of the button to the pad lever must act not only as a hinge, but the attachment to the button shaft must have some flexibility to move slightly along the axis of the lever as well.  Otherwise the button would also move in an arc and bind in the endplate.  With this in mind the length of the sleeve should be just long enough to hold the button on the lever.  Too long a length will hold the button too tightly to the lever and not allow any motion along the lever.  It should not be enough to let the button slide on the lever, but shift a little using the flexibility of the tubing.  Again, too long a length will compress the tubing limiting that flexibility.

    While replacing the sleeves, it may be noticed that some of the lever arms have been bent sideways as a result of the cocking of the buttons.  Also, the arms themselves may wobble due to the U bracket holding the axle being too wide.  A good quality pair of needlenosed pliers will be necessary to effect the adjustments.

Cheers,

Geo

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Thank you all. Especially shipcmo. Your advice was right on the money. Somehow I understood it all. I just ordered 10 ft. (minimum order) of latex rubber tubing from

McMaster-Carr. The closest I could come was 1/8" I.D. 3/16" O.D. with a 1/32" wall.

With your excellent advice I should be back in business in no time.

Thanks again mark996

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