alex_holden

Try saying his name out loud.

That's interesting. It implies unusually narrow chambers.

Thanks, that would be very interesting!

You could be right. I was assuming his finger was over one button rather than between two. That doesn't explain the presence of a left thumb button though - does this instrument have 30 buttons plus a drone?

It's hard to see much detail in the photo, but it could be the same design as the one in @Stephen Chambers earlier photo. The rows appear to me to be closer together than normal, and very near to the front/top (depending on your perspective). This implies a different internal layout from the standard 6" Jeffries 30b, because there wouldn't be room for the pads around the front end. Also, the earlier photo appears to show a truncated (4 buttons?) outer row on the left hand, and a left thumb button. My guess is this was done for reasons to do with action layout difficulties.

Here's the direct link - you can read the text of the book online for free, or pay a small amount to download it with the accompanying recordings in MP3 format (funds go towards the Concertina Journal's running costs): House Dance

Would you say there are drawbacks to building a 30 button that small, like limited dynamic range or stiff action (from too-short levers)? Is the keyboard spacing standard or did they move the buttons closer together? It would be interesting to see internal pictures of the reed pans and action to see how they did it.

If they don't have a single board wide enough, it should be possible to glue two narrower ones edge-to-edge like they do with violin backs. That is a bit more of an advanced woodworking technique though.

Most hardwood you buy from a reputable large timber dealer (not a little backyard sawmill) will already have been kiln dried. In my experience you do need to cut it oversize and let it acclimatise to indoor conditions, ideally for a few months. Weigh it regularly and write down the measurements. Once the weight curve flattens out, you'll probably find that it has warped a bit, so you will have to plane it flat and parallel again before you can use it. If using commercial birch plywood instead, I wouldn't recommend going thinner than the original, and it's not ideal to go a lot thicker either. You could start with 6mm ply, which is probably actually about 5.5mm, and plane it thinner. When I do that I always seem to find patches, knots, voids and other crap (one time I even found woodworm tracks!) hidden in the internal plies.

Traditional is quarter sawn European sycamore. American hard maple is similar and may be easier to obtain. Or perhaps some sort of mahogany.

I guess that explains how Wim was able to build it 3/4" smaller than a standard 48b treble. Nice.

Thanks Dana! It sounds like it could be worth combining multiple strategies.

Thanks. This photo is from the previous instrument I mentioned. It's a 6" wide C/G Anglo with long scale reeds, 31 buttons + a low D drone. My next client doesn't want the 31st button on the left hand, which happens to be connected to the chamber next to the drone, so theoretically I will have spare room to do something unusual with the shape of the chamber. I'm now thinking that the approximately L shaped arrangement in the final picture could be worth a try. I'll do some experiments and get back eventually. I do put tapered pans in the duets I build, but it's trickier to implement variable chamber depth on an anglo and leads to some other compromises (I did it on the first anglo I made). Theoretically for the drone chamber you could glue an extra deep section on the bottom of the pan, but I'm not sure it would be worth the effort.

From experience with the instruments I've built that have inner chambers, that wouldn't give me the effect I'm looking for here. It changes the tone slightly but doesn't noticeably reduce the volume.

Thanks Dave.