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Valve leather punches


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I've pretty much got all my tools in place for making most part of a concertina. 

 

The final set of tools that I need to make is a set of valve punches. 

 

My thought is to use lengths of tube of various diameters and squash in a vice to the shape of the valves, grinding down the edge (as with wad punches used for the pads) so as to make a sharp edge.

 

What have makers/repairers done in making valve punches?

Edited by SteveS
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I'm not saying it's the best way to do it, but I CNC milled mine from solid blocks of O1 tool steel and hardened them myself. I had originally planned to use them in my arbour press but it turned out to be less hassle to just whack them with a big mallet.

 

There are companies that will make "leather clicker dies" from a CAD drawing. Something like this:

https://www.weaverleathersupply.com/custom-clicker-dies

I'm not sure if they might struggle to make something as small as a concertina valve die.

 

There are similar dies available for cutting paper, card, foam. etc.

http://arrow-cutters.co.uk/Cutters-dies-formes.htm

 

(I haven't used either of those companies - they were just the first that came up in a quick Google search.)

 

If you go down the DIY steel tube route, you would probably want to at least case-harden the edge or they won't stay sharp very long.

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If you can find a company that makes clicker knife dies they will make them for you and it probably won’t be very expensive. They typically work for leather industries like the shoe industry. Here’s the outfit that made mine https://lucris.com.au


Clicker knife making is a dying industry but there will still be makers in your country. I wouldn’t be surprised if there were makers in or near Street in Somerset, former home of Clark Shoes. Cornish’s, who supply bellows leather parts are there and they would know of a clicker die maker. 

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I have been looking for press knives for valves for some time. Lucris weren't able to help. I have purchased some punches (pre-formed sets) from Ebay - some of the shapes match some valves but most of the larger knives are too big. I am going to try re-shaping in the workshop, though I don't hold out much hope of getting an acceptable shape and retain the cutting edge. The image shows a couple of the punches that work (15mm & 19mm). The larger one illustrates the problem. The upper valve was cut with this punch and is compared with a "shop bought" valve.

If anyone does find a maker who can make sets, I would be glad to find out.

IMG_0359.JPG

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Richard, don’t know if he is still in business, he is getting on, but try Peter Saville from JamesDeanDesign@bigpond.com.au, 0414 992 000. He is on the Princes Highway in Tempe, Sydney. He made a couple of knives for me a couple of years ago, well made. He has been in the shoe manufacturing business all his life. 
 

I think the principal at Lucris might have retired, his daughter is running it now. 
 

Both use a form of strip steel which they have on rolls. It has one sharpened edge (single sided) and they bend it to fit. It must be possible to buy it but whether it would be at an economic length would be something else. Either Lucris or Peter might tell you what it is called, which would make it much easier to find. Lucris used to work from a cardboard template, specifically manila folder! Peter worked from examples.
 

The only good reason for wanting a set of knifes is you can stamp out a large number of valves quickly.  The shape of them  is usually a taper with rounded ends. While the rounded ends have no function once the valves are installed, the taper may make a difference as the smaller tip area would have less square area and the root end would be similar in stiffness to a parallel one meaning the speed of lift and return could be different. But you can cut a taper into a square valve easily if you want that. I often find my standard valves will not fit a repair or some of my own chambers and have no hesitation in cutting one from scratch with square ends or trimming the sides down on an existing valve. If I was reordering a set of knives I would get a number of shapes in each length. 

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2 minutes ago, Chris Ghent said:

Richard, don’t know if he is still in business, he is getting on, but try Peter Saville from JamesDeanDesign@bigpond.com.au, 0414 992 000. He is on the Princes Highway in Tempe, Sydney. He made a couple of knives for me a couple of years ago, well made. He has been in the shoe manufacturing business all his life. 
 

I think the principal at Lucris might have retired, his daughter is running it now. 
 

Both use a form of strip steel which they have on rolls. It has one sharpened edge (single sided) and they bend it to fit. It must be possible to buy it but whether it would be at an economic length would be something else. Either Lucris or Peter might tell you what it is called, which would make it much easier to find. Lucris used to work from a cardboard template, specifically manila folder! Peter worked from examples.
 

The only good reason for wanting a set of knifes is you can stamp out a large number of valves quickly.  The shape of them  is usually a taper with rounded ends. While the rounded ends have no function once the valves are installed, the taper may make a difference as the smaller tip area would have less square area and the root end would be similar in stiffness to a parallel one meaning the speed of lift and return could be different. But you can cut a taper into a square valve easily if you want that. I often find my standard valves will not fit a repair or some of my own chambers and have no hesitation in cutting one from scratch with square ends or trimming the sides down on an existing valve. If I was reordering a set of knives I would get a number of shapes in each length. 

 

It's called die maker's steel rule, or more specifically "cutting rule" is the type that has a sharp edge. There are different varieties for different materials.

https://www.partwell.com/die-makers-steel-rules?page=all

 

I haven't seen how they bend them to shape; I'm guessing they do it cold to avoid having to re-harden the edge, which implies it must be supplied at a fairly soft temper so it doesn't snap.

 

When I made mine I copied the six standard Wheatstone sizes; if I was doing it again I probably would have made a few more with smaller steps between them (though it's not a big deal to go to the next size up and trim a bit off it). I sometimes find my biggest valve die isn't enough for a long bass reed, and I have to cut one out with a ruler and knife.

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Is is just tradition that we are expected to fit those “standard” style of concertina valves I wonder. I ask because I use leather accordion reeds, which are around 1/3 of the cost and work well. I mainly restore old wrecks where the cost of valves is significant to the value of the instrument.

They are not as pretty as concertina valves but seem to do the same job, given that the reeds are fine tuned after installing the new valves.

20210108_150207.jpg

Edited by Tiposx
Photo of valves added
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On 3/3/2021 at 6:33 PM, alex_holden said:

Incidentally, I have wondered whether the radius at the ends of the valve is partly because it would be more difficult to make a clicker die that has sharp corners.

My thoughts also...

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On 3/3/2021 at 7:17 PM, Tiposx said:

Is is just tradition that we are expected to fit those “standard” style of concertina valves I wonder. I ask because I use leather accordion reeds, which are around 1/3 of the cost and work well. I mainly restore old wrecks where the cost of valves is significant to the value of the instrument.

They are not as pretty as concertina valves but seem to do the same job, given that the reeds are fine tuned after installing the new valves.

20210108_150207.jpg

If they work then they work...

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