My First Reeds

[alex_holden]

My latest pair of blog posts are about how I made my first prototype reeds:

https://www.holdenconcertinas.com/?p=657

https://www.holdenconcertinas.com/?p=685

[David Hornett]

I enjoyed reading your blog, Alex. The end product certainly looks excellent. If you are interested I can email you a photo or two of my home made tapping jig -- I would never have thought of doing it the way you did, fascinating: such a simple idea.

 

David

[alex_holden]

I enjoyed reading your blog, Alex. The end product certainly looks excellent. If you are interested I can email you a photo or two of my home made tapping jig -- I would never have thought of doing it the way you did, fascinating: such a simple idea.

Thanks a lot, David! Yes, I'd be interested to see your tapping jig. My email is alex at holdenconcertinas dot com.

[StuartEstell]

Fascinating reading -- thank you.

[Steve Wilson]

Thanks Alex, very interesting. This is a futile mission you're following you know, there's no future in concertinas! Just joking, what you're doing is great but as you know I think an inexpensive midi concer would be the way to entice new young players. You are the sort of fella that could possibly make that happen. Perhaps you should think about that along side your traditional concertina creative adventure.

[Dana Johnson]

Nice job Alex! Hard free machining brasses may help with your chips. 260 Brass is common and widely used, but not great for machining compared to 360 or similar . I used to use a stereo microscope with the parallax problem. Had to look at the reed horizontally which put the problem only at the reed tip. I ended up buying a zoom monocular head which I stuck in an adapter for my binocular stand and attached a nice HD usb digital camera like you use for video chats. Works brilliantly ( with "eyeglasses" software that lets me mirror the image so moving the reed one way looks correct in the monitor rather than opposite.

Have fun. Off to a great start.

[alex_holden]

Thanks Alex, very interesting. This is a futile mission you're following you know, there's no future in concertinas! Just joking, what you're doing is great but as you know I think an inexpensive midi concer would be the way to entice new young players. You are the sort of fella that could possibly make that happen. Perhaps you should think about that along side your traditional concertina creative adventure.

Thanks Steve, I do have some ideas for an electronic instrument ('inexpensive' is the difficult part). I'm tackling traditional reedmaking first though, because my first instrument is going to be a prototype for MatthewVanitas's small rectangular Hayden 'Campaign Concertina'.

[alex_holden]

Nice job Alex! Hard free machining brasses may help with your chips. 260 Brass is common and widely used, but not great for machining compared to 360 or similar . I used to use a stereo microscope with the parallax problem. Had to look at the reed horizontally which put the problem only at the reed tip. I ended up buying a zoom monocular head which I stuck in an adapter for my binocular stand and attached a nice HD usb digital camera like you use for video chats. Works brilliantly ( with "eyeglasses" software that lets me mirror the image so moving the reed one way looks correct in the monitor rather than opposite.

Have fun. Off to a great start.

Thanks Dana! I started with standard CZ108 brass because I struggled to find a source for small plates of CZ120 (leaded) brass in the thickness I need. My initial attempts that went badly wrong were basically using the same settings as I'd previously used successfully for aluminium but with the feed rate turned down a bit. Actually I believe the root cause of my problem was that the waste chips were building up in the bottom of the slots, so when the tool came back round for a second pass the chips got 'smooshed' and friction-welded themselves to the flutes and the sides of the slot. The aluminium probably worked OK because the chips are much lighter so were thrown clear more easily. I don't currently have an enclosure suitable for flood coolant so that wasn't an option. What eventually solved the problem to my satisfaction was: modifying the DOC and feed rate to make bigger chips; increasing the RPM to the maximum my spindle can handle (10K) so as to better lift the chips out of the slot and throw them clear; adding a compressed air blast to blow the chips away from the work area and clear out any remaining chips from the bottom of the slot (it probably helps to cool the tool a bit, too). I also changed from two to three flute end mills, though I'm not sure if that made any difference to the chip clearance problem. I had some useful advice at the time from a Swedish harmonica maker called Joel Andersson on Instagram.

 

A better way to take microscope photos would certainly be handy; I'm currently just holding up my iPhone to one of the eyepieces!

[JimR]

The QA (Quality) dept at my job uses Celestron USB microscopes. Less than $50 US with great resolution plus 10x-40x magnification.

[Patrick McMahon]

It's a great blog Alex.

 

Did you notice much difference in tone, between your aluminium-framed reed and your first brass-framed one?

[alex_holden]

It's a great blog Alex.

 

Did you notice much difference in tone, between your aluminium-framed reed and your first brass-framed one?

Thanks Patrick! I didn't notice a big difference, but I wouldn't like to say more than that due to the tiny sample size and differences in profiling and other factors.

[Patrick McMahon]

Just out of interest, Alex, I notice your tuning marks go across the reed.

I've always filed up and down the reed, on the premise that you're not weakening one point excessively, if your filing is less than even.

What do you think, or others, on the subject ?

[alex_holden]

Just out of interest, Alex, I notice your tuning marks go across the reed.

I've always filed up and down the reed, on the premise that you're not weakening one point excessively, if your filing is less than even.

What do you think, or others, on the subject ?

Hi Patrick, the filing action at the rough profiling stage isn't exactly straight across, I slide the file sideways slightly as I push it forwards, which reduces the tendency to cut a groove. The file leaves a lot of shallow scratches across the reeds but I see those on the original reeds I am copying too.

https://www.youtube.com/watch?v=iCUK4iI8Fag

 

Also I did the final tuning using a fine diamond "file" (really more of an abrasive grinding stick) using a circular-ish motion, which leaves a lot of very small scratches in random directions.

https://www.youtube.com/watch?v=S37oliF8J78

 

I'm figuring this stuff out as I go along and would be very happy to take suggestions from the experts if I'm doing it wrong!

[Patrick McMahon]

would be very happy to take suggestions from the experts if I'm doing it wrong!

 

Me too. I have no idea if there's a right or wrong way. I do often notice that marks that were done in the factory are often pretty crude deep scratches, but done lengthways. But that might be just the ones I've noticed.

I have heard people say that using a rotary tool is not good. But I like it, I have one that's got variable speed right down to stop.

It makes it easy to grind along the length, keeping it moving to avoid too much in one spot. And I keep dabbing with a damp cloth, just in case some heat builds up. (which I doubt, but I do it anyway)

 

I was wondering what grade of steel you used for your first reed? If it cuts ok with the bench guillotine, and is easy to straighten after, maybe it's not a very hard springy steel?

Maybe the original reed was high carbon old british 735 steel, or similar, and that accounts for the brighter tone?

(the only reed I ever made was from a stainless steel razor blade, and that had a very soft tone, like brass)

Edited August 17, 2016 by Patrick McMahon

[alex_holden]

I was wondering what grade of steel you used for your first reed? If it cuts ok with the bench guillotine, and is easy to straighten after, maybe it's not a very hard springy steel?

Maybe the original reed was high carbon old british 735 steel, or similar, and that accounts for the brighter tone?

(the only reed I ever made was from a stainless steel razor blade, and that had a very soft tone, like brass)

It's hardened and tempered 1.1274 (C100S). Apparently it's similar/equivalent to 1095.

http://www.steelnumber.com/en/steel_composition_eu.php?name_id=358

[Patrick McMahon]

It's all a mystery to me, the properties of steel. I was surprised that you could cut the reeds so easily and straighten them afterwards, but I really don't know enough about it.

Maybe Dana Johnson can fill you in on what is the best grade to get. His Kensingtons have a great tone, and he makes his own reeds.

 

I would imagine that if you were making significant quantities, you would get best results by buying the steel non hardened, then cutting the reeds and grinding them to shape, before case hardening and tempering the finished reeds. Quenching steel hardens it, and then tempering reduces the hardness to the required level. But it would take lots of experience to arrive at the best compromise for the best performance, I think.

[Dana Johnson]

It's all a mystery to me, the properties of steel. I was surprised that you could cut the reeds so easily and straighten them afterwards, but I really don't know enough about it.

Maybe Dana Johnson can fill you in on what is the best grade to get. His Kensingtons have a great tone, and he makes his own reeds.

 

I would imagine that if you were making significant quantities, you would get best results by buying the steel non hardened, then cutting the reeds and grinding them to shape, before case hardening and tempering the finished reeds. Quenching steel hardens it, and then tempering reduces the hardness to the required level. But it would take lots of experience to arrive at the best compromise for the best performance, I think.

I use UHB 20 C strip steel from Uddeholm, but minimum orders are way beyond most people's needs. It is provided in slightly harder temper than the typical dark blue tempered 1095 carbon steel, but 1095 makes perfectly good reeds. It is incredibly impractical to start with annealed steel and harden and temper it after filing or grinding. That works fine for thicker things, but reeds cool off much too quickly, would decarbonize at their thinnest part before they could be quenched. Normal reed steel is hardened and tempered in controlled atmosphere furnaces to protect the thin steel from oxidization. If you buy a lot of it, they will custom temper it for you.

The UHB20C is designed to shear cleanly despite its hardness, though it is denoted as flapper valve steel ( for compressor valves) one of its listed uses is accordion reeds. When shearing spring tempered 1095, you need to use a low shear angle. High shear angles take less effort, but creates high bending at the leading edge of the cut. This can cause little curved micro ( sometimes not so micro ) cracking into the side of the reed. It can also create a cannelated cut where the shear breaks alternately on the upper and lower edges, looking like shallow battlements under the microscope. Those must be filed away or cracks can form at the corners. The harder the steel, the more readily it cracks. If you can rig up some support for the reed being cut with the bench shear, it will help to reduce the bending and help reduce or eliminate the twisting. that said, Geoff Crabb has the definitive info on using the bench shear for cutting reeds.

Dana

[Dana Johnson]

One further note, I have found that while the steel used can effect the ability of the reed to hold its set, variations on hardness within the practical range for reeds, had no discernible effect on tone. ( I made a reed after hardening the steel too hard to file. Then tested it over and over as I varied the temper to soft enough to stay bent when lifted. ) what does affect the tone is the length to width ratio, ( narrow reeds are smoother sounding ), clearance ( tight fitting reeds sound crisper to the point of harshness if overdone. ), mounting method and materials ( direct contact with reed pan as in traditional concertinas, or rail mounted as in hybrids.) The wood matters more than anything you do to the reed. The construction, chamber dimensions, end materials and thicknesses, all matter more than the reed, though when you make a single shoe reed to fit a concertina reed pan, but use an accordion style window in it, it sounds more accordion like. The vast majority of the sound produced is created by the reed modulated airflow, not wood vibration, which is heavily damped. The wood does absorb various frequencies selectively, and can color the tone by removing energy from the reed's wave form at those frequencies. Things like reed pan thickness, wood species, density and stiffness effect the final output of the reed. The same set of reeds in concertinas using a denser or lighter or softer reed pan even if the same species of wood, will sound different. Changing chamber depth has a substantial effect on tone and is worth trying different values to find your preference. Dimensions of instruments you like, are a good place to start, but given how many things effect tone, those dimensions may not translate completely to your own design and are still worth experimenting with.

Dana

Edited August 19, 2016 by Dana Johnson