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About alex_holden

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    Heavyweight Boxer
  • Birthday 02/06/1980

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    Wood carving, metalwork, Morris Minors, folk music.
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  1. alex_holden

    Introducing Alex Holden's #3: A Crane!

    Thanks very much RAc, it was a pleasure to work with you and I am glad you like the instrument! I look forward to hearing more recordings once you have had a chance to get used to it. The post @saguaro_squeezer referred to is the writeup on my blog here: https://www.holdenconcertinas.com/?p=1528 Regarding the reed frames, I can make them in either brass or aluminium (6082-T6). Brass is more traditional and has some advantages, but aluminium gives an appreciable weight saving per button. I discussed that in a bit more detail in the blog post. @Don Taylor here is the keyboard chart. The one for @Little John will be slightly different. Side point, is it the case that the stated button count for a duet includes the air button if present, whereas the count for an Anglo doesn't include the air button? This one has 45 notes + air. P.S. if I recall correctly RAc was the first to contact me about a Crane, and I was still thinking about whether to take it on when a couple of days later I received a very similar inquiry from Little John, which told me there are still players out there who are interested in this system.
  2. Well remembered, I forgot I recorded a video of that experiment. The owner of the instrument did later tell me he thinks it has a slightly mellower tone with the new wooden ends (which in his case was what he was hoping to get).
  3. I suspect it might not be feasible to build the action without rearranging the reed chambers so they are somewhat in line with the appropriate buttons. The Müllerization concept is possible because the new keyboard still follows the English pattern, it's just shifted and spaced out more.
  4. alex_holden

    old pitch and temperament - again

    Why not? It sounds like it's already pretty close to in tune with itself.
  5. Hi Brendan, I tend to use "reed' as a shorthand for "reed assembly comprising a frame, clamp, two screws, and tongue". I don't have an accurate way to measure the clearance - I fit the reed tongues to the frames by eye, looking at the light coming through the gap under a backlit microscope. I aim to get it as tight as I can without the reed misbehaving if I apply moderate finger pressure to the frame while I sound it on the tuning bellows (simulating what happens when the reed pan expands due to humidity and squeezes the frame). The tip to frame clearance can be very small because the frame doesn't tend to distort lengthwise. The side clearances have to be a bit wider if the reed is to perform reliably. As Chris suggests, it's possible to go tighter near the clamp than near the tip, though ideally you want to always have some clearance all the way to the clamp or the reed may be prone to misbehaviour (I've seen this on vintage reeds where a microscopic bit of oxide or dust or something is interfering with the almost-zero clearance near the clamp). The clearance should be even on both sides for good pitch stability. Shorter reeds can get away with tighter clearances than long ones because long frames are more easily distorted. As a very rough rule of thumb, I'd guess good concertina reeds have approximately 1-1.5 thou side clearance (25-40 microns) on the sides near the tip, tapering down to a bit less near the clamp, and they have maybe 0.25-0.5 thou at the tip (5-10 microns). There are one or two South African makers making acrylic reed pan boards for stability. There is some debate as to how this affects the tone of the instrument. Incidentally in the video there's a part where you refer to the shim blade thickness as "0.01mm or 100 microns". By my calculations that would be 0.4 thou or 4 thou. Did you mean "0.1mm or 100 microns"? This discussion gave me a thought. What if the clamped part of the tongue sat in a rebate that was milled a thou or two below the surface of the frame? I think it would have a similar effect to the harmonica "reed shaping" technique without the need to form a tight downward bend at the root of the tongue.
  6. Interesting idea, but it's a workaround for inaccurately fitted reeds. It shouldn't be necessary on high quality concertina reeds and would probably increase the likelihood of reeds sticking and buzzing due to reed pan movement. That said, it might be worth a try to 'soup up' a very cheap concertina particularly if it contains harmonica-style reed plates.
  7. alex_holden

    Desert island concertinas

    A desert island is an island that is uninhabited by people (deserted), not necessarily a dry sandy place. For example Rockall.
  8. alex_holden

    "tenor treble"

    Yes, that was the experiment I referred to. It was, roughly speaking, a normal reed with a second, upside-down frame screwed to the top of it, with the tongue clamped in a recess between the two. The main problem was that the two frames interfered with each other in a way that prevented the reed operating efficiently, reliably, or at anywhere near normal amplitude. It was also more time-consuming to make than a pair of standard unidirectional reeds.
  9. alex_holden

    "tenor treble"

    The reed assembly. The tongue alone wouldn't do anything if it wasn't clamped to the frame. It's the regular interruptions to airflow as the tongue is sucked down and temporarily blocks the opening that generates the sound of the reed. If you blow air through it the other way, the tongue just lifts up a bit and it makes a quiet hiss.
  10. alex_holden

    "tenor treble"

    Normal reeds don't sound when drawing air through them in the wrong direction. I once attempted to make a special bidirectional reed but it wasn't very successful.
  11. alex_holden

    Remaking ends by hand

    Well done!
  12. alex_holden

    Tapered Reed Pans

    Yes, but that wouldn't give you a tapered fit between the bellows frame and the reed pan, so it would be very difficult to get the pan out if it swelled a little due to humidity.
  13. alex_holden

    Tapered Reed Pans

    That's right, you make it too big to start with, then use the sanding machine to bevel the sides. At first it won't go all the way into the lined frame (and you tend to get an uneven fit because the frames probably aren't geometrically perfect), so you keep nibbling away at the sides a fraction of a mm at a time until it goes in snugly. You can see from this drawing what I mean about how the angles are different on each side with a tapered pan.
  14. alex_holden

    Tapered Reed Pans

    I suspect I'm failing to understand the question. Does this drawing help? Tilting the pan and then milling the top flat automatically gives the tops of the walls the correct angles to fit flat against the action board. The obvious way to taper the edges of the pan is to use a large disc or vertical belt sander with the table tilted away from the abrasive surface at the appropriate angle, then put the reed pan on the table bottom-down. The problem is if it's a sloped reed pan, the sides have different angles relative to the bottom. The way around the problem is to turn the reed pan upside down so you're referencing off the tops of the walls and tilt the table towards the disc instead. Unfortunately most disc sander tables won't tilt much if at all in that direction, so you have to either modify the table or make a wedge-shaped board and put that between the table and the reed pan.