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Adjusting key height


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Would anyone kindly share a photo of their bending tool used to bend the lever arms in order to adjust key height, and how exactly is it used? Also, what’s optimum key height above the action plate (when released) for an anglo concertina?

 

 

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Here's my piece of high-tech eqipment.  It's a flat bar with a slot sawed/filed in it to suit the diameter (or depth) of an action lever.  The picture shows it fitted round a Lachenal lever in a location to bend up or down and hence raise or lower the pad.  The slot in the end can be used to bend the lever left or right to centre the lever over the pad hole.  There's another slot on the other end which is a bit narrower. I aim for a button travel of around 3.0 - 3.5mm so I measure the button height, add on 3.0mm and bend the lever with the new pad on the end to se tthe height, then repeat for all other buttons and try to get them all at the same height above the fretwork.  Any less and there isn't enough air getting to the reeds, any more and it'll slow the fingers down.  All of this is in Dave Elliott's excellent Concertina Maintenance Manual (page 19 with a diagram of the tool and the procedure) and corroborated by discussions with well known makers/repairers.

 

My preference is to have the button close to the fretwork when it's pressed as this is more comfortable and gives a bit more "feel". This isn't always possible, depending on the button dimensions, number of washers under the button, position of the lever pivot between the pad and the button and so on but this is for me what sets the total height above the action plate

 

Alex West

IMG_4897 (1).jpeg

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Ok I get it now, thanks very much!  yes I saw the diagram on the manual but I didn’t quite understand it; it makes sense now. Its time to find a flat steel bar now..

 

Edited by rcr27
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If you are replacing pads, I find it much easier to bend the levers before the pads are attached.  I like to attach the samper(little leather disc) to the pad, and put the end bead on the lever and set it all in place, measure, adjust- then glue.  When the lever end beads thread on to the levers they are often not completely symmetrical- the radius from the centre of the lever can vary quite a bit- so sometimes you can make small adjustments to the button height(without bending the arm) by rotating the bead so a thicker or thinner side of the bead makes contact with the pad.  Hope that makes sense (I just woke up and am only halfway through my first coffee!)

Edited by Bill N
typo
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Thanks for the tips, it makes sense however wouldn’t the glue add a little extra height once dry? 

 

Also, how thick does the bar (bending tool) has to be? Would a stainless steel ruler work? 

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I haven't noticed much difference after gluing (in theory it would lower the button height)- the Fish Glue I use makes a pretty thin film.  Also, anytime I've done this I've been replacing all the pads, so any slight change (maybe .5 mm?) is even across the whole keyboard.

 

I made my tool from a common 6" nail, pounded flat and filed at the business end to a thickness of about 3mm.  Could be a little thinner (I got tired of pounding and filing), but it has to be pretty stiff- not sure your ruler would be stiff enough.  Also, it can't be too wide, as you have to get into some tight spots with it.

Edited by Bill N
clarification
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Bill

 

I agree that I do the major lever adjustment before putting the pads on, particularly to get the lever centered over the hole.  However, I don't panic too much if I have to make minor adjustments (occasionally necessary to button height) after everything's glued up

 

Alex West

Edited by Alex West
Name spelled wrong!
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I find it is essential to make adjustments after fitting the new pads.  New pads certainly should be all the same thickness, old pads are unlikely to be.

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