Melodeon.net Forums
Discussions => Instrument Design, Construction and Repair => Topic started by: Gena Crisman on October 09, 2018, 06:14:00 PM
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Hello, as per the title, I'm curious about Stops and Couplers, so, after searching around for a few days and finding little functional information, I've made a post. A lot of information I have has been gleaned from pictures, in particular those that were shared in this thread (http://forum.melodeon.net/index.php/topic,21478.0.html), this post specifically (http://forum.melodeon.net/index.php/topic,21478.msg258513.html#msg258513).
I imagine we're all familiar with the external function of registers/stops; you push a button or move a plunger up/down and it turns off some of the reeds in the instrument.
Usually a slide with holes/blocked off areas moves in and out of alignment with holes in the fondo/reed block. Sometimes this is moved manually, with a direct physical connection, or mechanically, with springs and levers (I guess?)
However, this means that the part of the mechanism that you interact with is on the 'outside' of the instrument, and the part that stops the reeds from playing is on the 'inside' of the instrument. This means the mechanical connection must travel through the barrier separating the two sides.
So uh, I guess how does that work? Are the holes just a really tight tolerance? Are there any particular things one is supposed to do to mitigate issues in that regard?
I'm also quite unsure the mechanics of how mechanical coupler switches actually work, and am very interested in reading more about them. However, I have no leads on what the school of engineering related to it would be called to search out more information.
I ask because a) I'm inquisitive and b) I'm considering my options for adding a Thirds stop to a Black Pearl 2 that I own. First concern: The thirds do seemingly all share plates with one another, so a stop slide should be fine on that front. Second concern: because of the giant fundamental reed block next to it, there should be plenty of clearance to do things underneath the chord reed block that might raise it up, as there's no chance of the melody and bass chord blocks touching one another. Other instruments may have issues.
I believe that, principally, the standard process would be to
1) Remove the existing padding from the fondo
2) Create a sandwich of thin pieces of wood or metal, with a slidable filling, to prevent direct pressure from the block (once secured) on the slide
3) Restore the reed block mounting points (presumably a very fiddly step)
4) Put a new layer of padding on the top of the sandwich
5) Mechanically link the slide to an external plunger, which will involve putting a hole in the case and probably removing part of the bellows frame end so that there's space for that.
6) (I presume) fine tune the reeds as they'll have been pushed 1-2 mm farther away by the slide mechanism
7) ????
Are there other concerns of which I am not aware? It sounds quite involved but not implausible as something a dedicated individual could do themselves. I have other... strange ideas, but, I think I should first try to understand the reality of how existing solutions would work, and ideally test on an instrument that isn't my main instrument.
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Adding a thirds stop can be even simpler. (1) no need to remove the gasket (padding) (2) no need to make a sandwich, just one layer works well. thats how most Italin made thirds stop work.
Other things to check"
(1) all the thirds reed plates are on one side of the block, move them if not.
(2) the reed plates are spaced far enough apart so that the sliding register plate can park the holes in between the reed vents.
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Well, that's interesting information! Just having the slide held in place by the reed block would be simpler. However, well, I'll attach a photo and see if that works (if not, it can be found here (https://i.imgur.com/VD17Ojh.jpg)) - attached ought to be a photo of the present state of the bass end.
The thirds are all on the one side, the side with the 4 holes (it seems anyway) - they're the top side as viewed of the trio of air holes, so, there doesn't appear to be any obvious issue there which would require them to be moved. Also, there is clearly plenty of space for the parking of said holes, so, those (very valid) concerns are alleviated in this case. I am kind of surprised that that is the situation, but, there you go.
But, so, you'll have to help me a little here. When you say there's no need to remove the gasket, are we saying one could build a slide mechanism floating on top of the gasket, effectively placing the physical slide on the reed block side of the equation, but, just clamped in place via the reed block fixing down mechanism? That would be much simpler, but... I haven't seen that. I guess I got stuck thinking the gasket would have to be in a particular place but... there's really no reason for that to be the case I suppose, it just needs to be part of the clamping mechanism and anything that will transfer the pressure could be added in between the block and the gasket, right?
When you say one layer, do you mean, no static flat plate of 'bread' at all? Or, just 1 'slice', ie, Fondo, Gasket, Bread, Slider/Filling, Reed block? I.. should probably draw a diagram at this point.
I should also ask, are there material concerns such as friction etc? I've seen both wood and metal slides. Presumably friction is both bad (hard to move) and good (stays in place). I've heard of magnets to help a low friction slide stay in place but, I'm not sure how to avoid having a high friction slide.
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Your reedblock looks ok for fitting a slide. The slide does indeed just run directly between the base of the block and the gasket. When these are factory fitted the block has a shallow channel routed into the lower face of the block. When retro-fitting you can glue the same material on either side to form a channel. I’ve usually used 1mm aircraft ply to make the slide.
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I've retro fitted a thirds stop to many Italian boxes. I always rout a 1.5mm deep channel in the reedblock then make a 1.5mm plywood slide to fit.
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Well, huh, yeah, ok then. I guess I have another project to work on. I think I may have access to the right kind of equipment to shave the reed block down, but, being that I'm a bit of an amateur in this regard, I assume I should do my best to make sure anything I do can be undone.
Given the above, for double confidence, I disabled those reeds by sticking a bit of card over them temporarily, and ran the instrument through a spectrum analyser. Output is attached, and shows that it is indeed all the thirds that are disabled. I could have done the reverse and just used a tuner I guess but I also wanted to hear what it sounded like (weird!).
Am I correct that adding something in as a spacer, rather than shaving down the block to fit one, would affect the tuning? I have a layout tweak on my agenda sometime soon that I feel is outside of my experience level to do, and while I think I could do the work discussed here myself, I'm not confident I could also retune the chords competently if they are likely to drift. So, it'd be helpful to know if you would expect that kind of change, so I can kinda plan things to pan out, I guess.
And, do you really just put a hole through the side and a metal rod through it, and that's fine? It seems like it shouldn't be fine, for some reason...
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If the holes in your register slide don’t obstruct the vents in the reed block, and if you only add a mm under the block then any tuning change will be hard to detect.
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"And, do you really just put a hole through the side and a metal rod through it, and that's fine? It seems like it shouldn't be fine, for some reason..."
Yes, absolutely fine, there are four on a one-row four stop melodeon, so it definitely works. I have drilled holes in many a Castagnari :)
My method. Glue block of wood (stopblock) to stop slide. This is a shear joint so drill shallow "grip" holes in both plywood slide and stopblock, lightly sand off burrs. Use Araldite not wood glue. Don't clamp!
Fit stop slide in place under reedblock (channel already cut).
Make a temporary woodblock that fits dreckly between the top of the reedblock and the bottom of the stopblock jamming it against the top of the instrument casing.
Drill a pilot hole for the stoprod thread through the casing and through the stopblock.
Remove temporary woodblock, reedblock and slides.
Drill casing to diameter of stoprod. Make sure the rod is a snug fit in the hole and try to drill the hole at 90 degrees. :-\
If you wish to get a bit nerdy, bush the holes with Teflon, a la Doug Briggs (hero :) )
Re-assemble and screw the damn thing home.
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A bunch of info here as well: http://forum.melodeon.net/index.php/topic,7527.0.html
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A bunch of info here as well: http://forum.melodeon.net/index.php/topic,7527.0.html
Thanks for this!
So, I've worked out basically the following.
First of all, there's actually a bunch of clearance between the bass and treble reed blocks (at least 4 mm) so, I could probably put a bunch of stops everywhere, if I wanted to. I guess if I'm doing a thirds stop I might as well consider a low fundamental stop, too.
I really appreciate the information that's been shared already, but, I do have an issue that I don't think anyone has yet alluded to a solution for yet.
With the way the reed blocks mount currently, there's kinda a lot of material in the way of any mechanism. Currently, metal tabs are screwed, with a single screw, into a block of wood (block A), and these apply pressure on the edge of the reed blocks to hold then in place. These are long metal clips, like this (http://www.cgmmusical.co.uk/CGM_Musical_Services/Hardware_Misc..html#25)
Past this block, there is another block (block B). At first glance this exists for the bellows clip screw to fix into, but, I believe is actually there to provide space past the separating wall for the rotella bolt to advance into. This block B is probably larger than it needs to be, but I don't think it is a big factor.
The bellows frame also extends into this part of the instrument, and when attached the gap between the bellows frame and the barrier wall measures around 8 or 9 mm, so some amount of the frame may need to be removed.
So, if the slide must extend out past the foot print of the reed block in order to be connected, there appears to be a puzzle laid out in terms of exposing enough slide in the right place to attach a stop rod to it, while also being able to secure the reed blocks in place at the same time. I've attached a photograph of the area in question and tried to annotate it showing the wingspan of the metal plates.
Due to the amount of material I believe I would need to remove, the answer that I would think to go with would be to attempt to separate Block A from the instrument entirely (I guess it's hide glued in, so, warm + moisure + pallet knite?) and then create a new clamping system that allows a clear path for a slide mechanism beneath it. The other end of the block is held in with a clamp like this (http://www.cgmmusical.co.uk/CGM_Musical_Services/Hardware_Misc..html#24) - my inclination though is to produce a solution that offers a similar clamping force to the existing one. Is any of that a sane course of action? Clearly this is an issue that would be confronted fairly frequently, so, am I missing a, let's say, more trivial solution?
I have some 1mm thick PETG plastic sheeting that I intend to make some test slides with to see how that goes. I have no idea if that's a terrible idea since I've never read of anyone using plastic, so, I guess maybe I'll find out? (Reasoning is that it's super cheap and I have a bunch)
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Ah yes, you do have rather a lot of timber in the way so surgery will be required. You are, however, on the right track.
Plastic slides are fine, Weltmeister have been using them for years.
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Not sure if this helps, but here is a photo of the interior of a Castagnari Laura. The top end of the instrument is to the left.
The photo shows the clamping arrangements for the reed blocks and the exposed portion of the aluminium slider which passes beneath the thirds reeds in the chords reed block, and which has vent cutouts to open/close air flow into the reed chambers. The upper reed block is for the chords; the lower block for the basses.
The left-hand end of the slider is not visible in the photo but it is glued to a small block of wood which, in turn, has the shaft of the external thirds 'mushroom' stop screwed into it.
As you can see, the LH reed block clamps are screwed into a rectangular wood block. The block and the line of the clamp are both offset slightly to allow space for the slider. There is no bass fundamental stop on this particular instrument but if one were to be fitted, a similar off-set would be required on the bass reed block clamp.
From your photo, it would seem that the clamping arrangements are the opposite way round: the top end of the instrument is to the right and this end also has the flat clamping plates. You would need to modify your wood block 'A' and cut a shallow channel for the slider to run in, and also modify block 'B' or drill through it for a slider stop shaft.
It might also be worth investigating whether the clamping plates could feasibly be swapped from one end to the other, so you have the flat plate at the other end of the reed block, as in the Castagnari photo. This would then allow you to have a smaller wood block 'A' which might give you more working room to install your slider (not sure about that though - would need to see the whole bass-end interior).
Anyway, the Laura photo might help you as an example of how it is done on Castagnari instruments.
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Thanks Steve, that saves me opening up a Castagnari :)
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This is the coupler I have fitted for thirds on my Pressed Wood
https://photos.app.goo.gl/8ADDHyU5WzibeXtg7 (https://photos.app.goo.gl/8ADDHyU5WzibeXtg7)
The block that holds the reed block in place had to be cut in half and the chord side removed and notched so the the slide could pass under it. It was the refitted (glued and screwed) and modified to place a clamp for the reed block which used to slide under rather tan be clamped.
https://photos.app.goo.gl/wXeNuyxkJjnT9rbo9 (https://photos.app.goo.gl/wXeNuyxkJjnT9rbo9)
Reed block in place to show block clamps.
Can do better photos etc when not in a holiday cottage in Norfolk
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Clever design, Lester.
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Steve and Lester, the photos posted help a lot, I don't have access to any instruments with slides and I have been able to find surprisingly few pictures showing the mounting solutions in use & what sensible options look like.
It might also be worth investigating whether the clamping plates could feasibly be swapped from one end to the other, so you have the flat plate at the other end of the reed block, as in the Castagnari photo. This would then allow you to have a smaller wood block 'A' which might give you more working room to install your slider (not sure about that though - would need to see the whole bass-end interior).
You are correct that the clamps are currently the other way up in my instrument vs the Laura. I've investigated simply swapping them from end to end, and good news, I can absolutely reverse the mounting solutions. I guess drilling a small hole into the reed block to allow swapping them over is of little consequence, so, a solution like that shown in the Laura is likely the route I shall take, as if I make a complete mess of everything else, the reed block could still be perfectly clamped in place with the remaining material.
I believe my plan then would be to first reverse the mounts, and see how far over I can comfortably offset the thinner sort. If I establish this, then I can consider simply removing parts of Block A entirely. My preference is to try and avoid having to remove, work on, and then reglue any parts as I have no experience with hide glue and I know there are reasons not to use eg PVA. So, my plan would be to do the work in situe by using eg a hand drill with depth indicator to gently make most of the cuts across the block, finish the cut with a small file or blade, and then remove the offending sections via detaching their glue.
If I make a slide that just runs underneath just the set of holes I wish to block, I'll need my slide to serpentine from the 'inside' side of the reed blocks to the outside. I noted though that Lester's slide appears to run the whole width of the reed block. I imagine that increases the friction somewhat and most importantly increases the risk of the slide being able to move left to right out of alignment if you don't have enough going on to prevent that from happening, which is an issue I may run into.
So, I believe I have a plan:
A) Relocate the mounting hardware to a more convenient orientation and check that the reed blocks don't fall off. Also order some Stop plungers.
B) Use a scanner/copier to produce an orthogonal projection of the instrument and reed blocks and spec out my slides and work out what looks it would make sense and will actually be able to move enough to do the job. I suspect the holes in the blocks and the holes in the fondo are out of alignment so pick one of those to match up with I guess.
C) Try to actually make the slides out of the material I've considered and see if it works or if it's garbage.
D) If successful, believe in myself enough to remove parts of wood from my expensive instrument and test fit the slides, see if they work etc by manually moving them up and down with the instrument open, then reassemble play etc.
E) If successful, Drill holes in to my melodeon... presumably while screaming? Then put the Stop rods through them.
I will update with any progress, pictures or diagrams etc as I generate them. Thank you for the guidance & sharing of experience.
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"Drill holes in to my melodeon... presumably while screaming?"
You're a better man than I am, Gunga Din!
(No sexist or racial smears or slurs intended, so there's no need for any recriminations, thank you, Big Brother!)
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I noted though that Lester's slide appears to run the whole width of the reed block. I imagine that increases the friction somewhat and most importantly increases the risk of the slide being able to move left to right out of alignment if you don't have enough going on to prevent that from happening, which is an issue I may run into.
The reason that the slide is the full width is because I was working with a hohner chord block which, even after some clever tuning stuff*, has the thirds reeds on alternating sides of the block.
O O O O O O
O O O O O O
*Hohner in their wisdom don't put the thirds for the pull and push on the same reed plates
eg G chord G B D
D chord F# A D
So as a start it is necessary to do tuning wizardry to end up with
eg G chord G B D
D chord A F# D
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....If I make a slide that just runs underneath just the set of holes I wish to block, I'll need my slide to serpentine from the 'inside' side of the reed blocks to the outside. I noted though that Lester's slide appears to run the whole width of the reed block....
As Lester has explained, the thirds reeds in Hohners tend to be on both sides of the reed block.
However, on your Dino Baffetti instrument, in common with most Italian instruments, and as you have mentioned in your earlier post (http://forum.melodeon.net/index.php/topic,22920.msg274100.html#msg274100), the thirds reeds for both push and pull are on the same reed plates on one side of the reed block, so your slider doesn't need to be the full width, only half width, which makes the job easier.
As Theo mentioned earlier (http://forum.melodeon.net/index.php/topic,22920.msg274101.html#msg274101), you could use thin strips of 1 mm aircraft ply to form channel edges on the base of the reed block, each side of your thirds reeds for your slider to run in. You would also need to attach a similar strip of ply along the other edge of the reed block adjacent to the tonic/fifths vents, and short strips of ply transversely to isolate each pair of tonic/fifths, otherwise you will get leakage of air between those reed chambers of adjacent chords.
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A) Relocate the mounting hardware to a more convenient orientation and check that the reed blocks don't fall off. Also order some Stop plungers.
Stage A complete!
The larger metal clips were a direct translation from one side to the other. In order to fit the smaller clips to the other side, I decided that I would position them so they could mount into the original holes left by the larger clips, because from this position, when rotated ala Steve Freereeder's picture of the Laura, they would be well within the margins of where I expect to trim this block in the future - the margins informed from how close the existing holes were to the edges of the block. The different kinds of metal clips are of differing thickness, and as the main screws that secure the clips were identical at both ends, the holes in the wood were of different depths, so, one side was now too shallow. I measured 12mm depth for the original holes where the smaller clips had been, and used a hand drill to extend the existing holes on the top side of the instrument (noting that the pieces of wood were of the same size at either end). I attached the clips to these mounting points, and made pilot marks on the reed block - the smaller holes into the block take smaller screws, measured to 7mm deep so, I drilled them to that and then screwed the whole lot together to I guess little to no fanfare, but, I felt pretty good about it. Then, I took it apart one last time, rotated the mounts into the intended offset position, made even more holes (to the 12mm depth again) and put that all back together.
It currently seems stable and not like the reed blocks are being pulled at an angle or unevenly as things stand, so, I'll have a good play tomorrow and see if anything feels different, and then await the arrival of some new ink cartridges so that hopefully my scanner will stop being off limits as the part of it that is also a printer is constantly screeching until appropriate tribute is paid.
I should say, I noted Lester's slide construction being of full width mostly because I personally would actually find it easier to make a single, reed block footprint sized slide rather than several strips that must all have straight, parallel edges and interlock. Given the thirds and bass fundamentals are all located on the 'inside' side of my reed blocks, it would also perhaps simplify the construction if the whole thing can move, but, again really I'm keen to design to a scanned image rather than a measured copy as I don't have any good measuring tools, and the equipment is sadly out of action. I would love to know, how does your full width slide feel, Lester? Appreciably different or awkward in any way?
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Stage A complete!
It will only get easier now you have drilled your first hole in your melodeon (:)
I should say, I noted Lester's slide construction being of full width mostly because I personally would actually find it easier to make a single, reed block footprint sized slide rather than several strips that must all have straight, parallel edges and interlock. Given the thirds and bass fundamentals are all located on the 'inside' side of my reed blocks, it would also perhaps simplify the construction if the whole thing can move, but, again really I'm keen to design to a scanned image rather than a measured copy as I don't have any good measuring tools, and the equipment is sadly out of action. I would love to know, how does your full width slide feel, Lester? Appreciably different or awkward in any way?
Full width slide is fine and, as you say, it saves having to make the parts separately. Though if I were doing a box like yours and my routing skills were up to it I would follow Rees' suggestion of routing a channel for the slide in the reed block.
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Good progress so far Gena!
A few points occur to me:
1. The block which supports the rotella wheel is still going to cause you problems at the moment. I suspect it doesn't need to be as large (long) as it actually is. If you could make it shorter at the end nearest the chords reed block it would help in getting the slider and the stop shaft in a better alignment.
2. Your newly positioned clamp at the top end of the chords reed block has the screw right where you need your slider to be. The offset for the screw/clamp needs to be further down, i.e. towards the tonic/fifths, nearer the air button pallet.
3.
I should say, I noted Lester's slide construction being of full width mostly because I personally would actually find it easier to make a single, reed block footprint sized slide rather than several strips that must all have straight, parallel edges and interlock.
Lester's full width slider works well because of the alternating side layout of the thirds reeds. In his photo (https://photos.google.com/share/AF1QipOMrcqquGYjh1QcDTuhlOfsfUpsA4WJBb3cpCQdzOPE469kPV_c3opnt7V1FUsPCw?key=RXpNaUpvTW9KRjlRVlZEaW9qMDN5aTd6WkpteEVB), you can see that he has an elongated cutout for the tonic/fifths reeds; these must be always kept open regardless of the position of the slider. The alternating layout allows room to make the elongated cutouts because there will always be sufficient 'solid' wood remaining to accommodate the single thirds reed cutout to be in the closed, as well as open, position.
Your situation is different. All the tonic/fifths reed plates are on one side of the reed block and these must have airflow to them at all times regardless of the slider being open or closed. The tonic/fifths reed plates (and hence the chamber openings) look to be quite closely spaced, so on a full width slider I don't think you will have the room to make either individual or elongated cutouts for these reeds which would always ensure full airflow; either in one position or the other, some of the 'solid' slider would always obscure a chamber opening. Without careful measuring I can't be totally sure, but it seems that way to me just by looking at your photos.
In this instance, one solution for a full width slider would be to have a single elongated cutout running the full length of the slider to ensure air is always getting to the tonic/fifths. However, such a long cutout may risk weakening the slider; the last thing you want is a broken or distorted slider occurring at some future point after everything has been glued down into place.
Edited to strike out stupid ill-thought out suggestion, sorry! See Lester's subsequent post!
This is why I suggested a narrower slider with minimal cutouts, and the 1 mm ply strips to guide it and also to isolate the tonics/fifths.
Disclaimer: my only experience with installing sliders has been on the two 1-row 4-stop instruments which I've made, where the sliders were built in right from the start. I've never attempted a retro fit on an instrument like yours.
... Though if I were doing a box like yours and my routing skills were up to it I would follow Rees' suggestion of routing a channel for the slide in the reed block.
Yes - I agree that this is the best option for your instrument. Perhaps you can find a joiner/cabinet maker locally who has a routing machine and could rout the channel for you? But failing that, I would go for the plywood strips option.
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In this instance, one solution for a full width slider would be to have a single elongated cutout running the full length of the slider to ensure air is always getting to the tonic/fifths.
If you do this air could leak from a tonic/fifths reed pair with the pallet open to all the other reed pairs. You would need to have four separate cutouts
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In this instance, one solution for a full width slider would be to have a single elongated cutout running the full length of the slider to ensure air is always getting to the tonic/fifths.
If you do this air could leak from a tonic/fifths reed pair with the pallet open to all the other reed pairs. You would need to have four separate cutouts
Yes, of course you're right, that wouldn't work. :|bl
Looking again at Gena's photo (attached again below for convenience) there should just be room for the four separate cutouts which allow the tonic/fifths pair to have air at all times. For each tonic/fifths pair you would need a cutout length equivalent to three pallet hole openings, and seeing as there is a pallet hole-sized equivalent gap plus a margin between the pairs, it ought to be feasible. (:)
Looks like you should be OK for a full width slider, Gena! You just need to be very accurate with the measuring and cutting of the slider cutouts.
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You don't need a full width slide in this case it just makes for extra complication. The picture shows what I do. The two hatced parts are glued on to the base of the reed blocks with holes cut to match the vents for the tonic and fifths reeds. between them they form a channel for the moving part. I have shown the holes as circular for convenience of drawing, but they should match the shape and size of the vents in the reed block.
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You don't need a full width slide in this case it just makes for extra complication. The picture shows what I do. The two hatced parts are glued on to the base of the reed blocks with holes cut to match the vents for the tonic and thirds* reeds. between them they form a channel for the moving part. I have shown the holes as circular for convenience of drawing, but they should match the shape and size of the vents in the reed block.
Best solution of all!
*I think you mean tonic and fifths reeds
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Corrected
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Scanner is back up and running. Attached is a close approximation of the reed block holes positioned in the bass end (should be 100 dpi). I scanned the bottom of the reed blocks and, crucially, mirrored them, then positioned them in their roughly correct location over a very blurry scan of the bass end. Should only be the 'blur' of the scan out of alignment at worst, so, a few mm left/right which isn't a grave concern to me as any final positioning based on this would be by hand anyway.
I also froze my fundamental reeds today to verify that if wishes were horses, I'd like to add two stops, and I can say that, yeah, freezing those big bass reeds makes my black pearl 2 much more mild mannered, and I mean, if I'm puzting around in here anyway...
One thing I would like to point out, that I feel has not been considered heavily is that, using a completely straight slide for both thirds and fundamentals, because these reeds are both located on the inner side of the blocks, the slide positioned very close to the center line. So, the stops, if you don't relocate them at some point in the mechanism, the plungers may be positioned such that they could block the top bellows clip from working (memories of the 2v Oakwood demo box keep coming to mind). I'm not sure how one might traditionally account for this, probably with the block the plunger attaches to? My intention is to try and make the slides themselves account for this by widening them at the top to move around the obstacles, hence offsetting the mounts inwards, rather than outwards. I was concerned that setting them outwards would, again due to the screw position, render the 'arms' that would run up too narrow, but, I'm not sure my plan is all that much better, so, I'll have to see how the material behaves and consider my options.
Now, I don't intend to make a full width slide, and as suggested plan to use hatched/static buffer material Theo/Rees/et al have used to make a track for a slide to follow. But, since I have to craft the slide from whole cloth anyway, I am considering my options for, let's say creatively getting around any issues that I don't want to solve by making modifications to the instrument itself - I don't really want to remove or alter parts of it that I don't strictly have to, even if I'm effectively just making more work for myself. I might find that some of the work I do impacts something outside of my expectations, so, my core methodology is driven by making sure I can basically undo it all at any time, and you'll likely see that I continue to make decisions with that in mind as time goes.
I'd also like to note that the wonkyness of the holes in the reed block is an interesting issue to contend with. I'm not sure how much of a border the holes cut into the 'hatched' section will require in order for the materials to remain strong - hopefully the answer is not a lot! I also found that there's just like, a hole, in the side of the fundamentals reed block that connects to the 2 of the chambers... they are at least for the higher and middle of the same fundamental note, but, I'm pretty sure the air isn't suppose to be able to get out that way, so, that's cool. I put some tape over it.
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I have had a very busy weekend! I have completed several of my stages and took photos as I went, so, while my journey is over for now, hopefully this will bring some people along for the ride. Plus, I've only been working on the stop for thirds so if I've missed anything crucial, I can get pictures of it while doing the Fundamental stop (if I don't die between now and then...)
Stage 2 - design 'something'.
So, I used the scan I posted previously to draw ideas for the slide on, just keeping to 200dpi (the attached image is at 100 dpi to reduce file size) and using an image editor to draw around the things I felt I needed - I knew this would just be a guide for things ahead so, approximations that would come out in the wash were fine. Knowing a full width block was fine, I investigated my options for making sure the material maintained a reasonable width by putting a funny old S bend in it.
Stage 3 - see if I can make it and believe that it might functionally work.
I arranged these coloured sections onto something that would fit on paper, loaded some card into the printer, and printed the graphics out. I cut them out with a scalpel and used some pritt stick to glue the templates onto an A4 sheet of this (https://www.amazon.co.uk/gp/product/B007JUSHG8/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1), an A4 sheet of 1mm thick PETG clear plastic sheeting which I happened to have. This is a pretty flexible plastic, honestly - since it's PETG, it's also a thermoplastic, so it can be heated up and shaped and it will maintain that shape, although since it's so thin it will still flex a lot. The material is quite easy to cut with a blade or a drill, but can be a bit of a pain with saws/files as it can end having loose stringy ends. But, it works for me - if you want to smooth edges, it responds well to polishing, especially machine aided polishing, but beware you can abrade material away really easily.
Anyway, I lined up the straight edges of the slides templates (where possible) with the external machine cut edges of the sheet, to try and reduce the the work involved in getting long straight edges, and glued them on. Then I cut them out - literally, with a pair of scissors. Once I had these, I decided the most efficient way to get them as straight as possible on both sides was to run a straight edge by the head my rotary tool of choice while it was cable tied to the leg of a table. This worked concerning well, and I had, where it counted anyway, straight enough edges on all of my pieces. I drilled pilot holes into all of the template holes to match the reed block and then slowly expanded these up half of the way with suitable tool in the dremel.
At this point, I removed the coating and templates from the plastic and made use of the fact that it's transparent to simply lay the pieces on the reed block and mark which direction the holes needed to be dragged in order to line up - I would then drag them over with a round & rounded file, and then actually round them out with the next size of drill I needed to use. They're not perfect but they're really very close to matching - far closer to matching than the holes cut in the fondo in the instrument, I might add. This took me pretty much all of my allotted time I wanted to spend on it on Saturday day time, important because that used up all of the day where power tools were friendly to use.
Feeling confident that the material seemed to be ok to use, and that the mechanics of the functionality made sense, it was time to advance onto Stage 4, hacking up the instrument to allow any of this to fit. I knew that I wanted to pursue this sufficiently that even if the slide breaks I'll just be looking to remake it out of a better material, so, I felt safe progressing. Plus, the rule I set for myself was no power tools to be used on the melodeon itself, only hand tools, so, I was able to make a bit more progress yesterday before packing up.
To be continued...
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Stage 4 - creatively relocating offending material
On my instrument, there were two parts of the instrument that are in the way. Firstly, there is a piece of wood directly above the reed blocks, that the block is secured to. Secondly, there's the bellows frame, which while it has a cutout to go around the existing block near the edge, would need an additional cutout to allow whatever it is that secures the external plunger to the slide to move up and down. It would have been possible, I suppose, to build in mind of having the bellows frame there, but I decided that I'd rather cut a piece out since there was already a large cutout on the bottom side of the frame for no reason, and this clearly couldn't be that bad of a thing to do.
I began the process by modifying the bass end - removing material from where the attachment block lined up with the corner block to just before the material curved away, to give, I suppose, 2 points of contact with the reed block. I used my trusty hand drill with tape on the bits to indicate depth to just slowly removed material. Once these holes were expanded up to the point of having no or very thin walls, I joined them up by using a scalpel, and then repeated the process along my other intended cut line. My goal was to get down all the way to the fondo beneath it, and just cut a perfect notch out.
This process was really hard work - this wood is hard and drilling all the holes by hand was quite a bit of effort - I got a blister from it. I'm reasonably happy with the result but, well. mainly of note is that the 'corner' that I left behind serves basically no purpose because the reed block doesn't actually touch it. So, it would probably be a lot easier to make one cut and just take the whole section off, if you can get the hide glue to detach or fancy trying to kinetically shock it off. I was far more cautious, only removing the glue when most of the wood was already gone - moisture worked well for this and made the glue go from clear to opaque and easily scrape away. In any case, having a proper chisel is probably the first thing I'd get for next time, and accepting power drill use the other.
I followed Rees' advice to Epoxy a block of wood to the slide, so I roughed up the faces, and just stuck them together with a 5 minute epoxy. After getting them on one another, I used trousered sticky tape to line the area where they would actually sit, and put the slide and reed block et all into the instrument, and ensured that the block lined up with the maximum position of the slide, flat against the top of the box. The tape would catch the inevitable drip of epoxy that would escape (it did) and help me feel confident the block was positioned correctly.
While waiting for that to set, I moved on to the bellows frame. I'd positioned the bellows on the instrument and marked the material I'd need to remove. I used the tried and true 'drill holes then link them together' technique to remove most of the material, and finished with scalpel and file. A small square shaped file was useful for getting into the corner. I also taped a piece of cardboard on to protect the gasket.
I then realised I'd removed the wrong part of the bellows frame - I'd removed material from the bottom side rather than the top side. I spent so much time making sure I was taking it off of the bass end, I forgot that it can go on either way up, so, I had to do all that again while feeling like a prat. I wrote 'woops' by the mistake and I'm pretty sure that absolves me of any wrongdoing. If this was the big mistake I was going to make, I'll take it.
Once the block was secure, I put everything together and manually actuated it into each position to verify that the stop was working correctly. After playing a few tunes in either orientation, it certainly seems to? I can't detect it being wrong. After playing and discovering no issues, it appeared that stage 4 was completed: the stop works, you can move it, all that remains is to be able to manipulate it from the outside.
To be continued...
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This is lovely to read, Gena. I'm on the edge of my seat, waiting for the next episode!
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Stage 5 - screaming
I measured out where the stop would go, externally - exactly 1/3rd of the way across, with the same distance from the edge as the bellows clasp screw. I mean, if I have to look at it I might as well try to position it as exactly as I can. I marked the point with the top of a scalpel.
I worked out on some test wood the size that the metal stop plugs (Thanks, Charlie!) would need. They might thread, if forced, into a 3 mm hole, but really wanted a 3.5mm hole drilled for them.
I clamped the block I'd attached to the slide in position as best as I could, with a piece of material under it to stop it flexing out of alignment. Because I was proceeding by hand, rather than with power tools, I figured this would be just fine as I would have time to fix any issues.
And then, well, in no uncertain terms: drilled a hole into my melodeon. It was easy, almost too easy honestly, the same way someone might nonchalantly pull out the plug out from the bottom of a boat.
I went up, size by size, in 0.25mm steps until I hit 3. At this point the next drill I had was 3.5mm. I was having trouble with the drill bits slipping in the hand drill - I ended up breaking a drill bit earlier in stage 4 in fact. The 3.5 mm cleared through the top of the box but was slipping trying to drill the slide block. No matter I thought - I'll just use the electric drill to finish the job - the box is done, I cleaned the edges up with a countersink bit (twisted by hand) so getting the hole in the block this is the last step!
Disaster strikes - under the power of the electric drill, the slide block split in half. I have a hole in my melodeon and the only plug I've got has nothing to hold onto. I contemplated stripping the block off and starting over, but, I decided to try and make the best of it. I epoxied the block back together and knowing it wouldn't take the drill, used my 3mm tungsten carbide cutting bit from my dremel once more in the hand drill to gently bring the size of the hole up to the needed size.
Finally, I was able to then thread the stop plunger into it and for the first time actuate the slide by the intended means. Every time I'd tried to move the slide with the reed block in place by hand, it had seemed almost impossible - I was getting very worried. Using the plunger stop top though, it was easy! It felt just fight. The wood block is a liability, and the hole into it has drifted slightly, causing the stop rod to be slightly angled, I think, but, that is something I can address in the future.
One final short update to go...
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That was like watching the heroine running upstairs to escape the monster, "Don't do it, don't go up the stairs!" It must be time for another cup of tea, all this tension!
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Thirds stop completed!
So, at least until that block breaks back in half again, I have a functioning thirds stop! It feels happy to move yet resistant when actuated, so, I'm pretty happy with how it feels. I'm done for this weekend though - next weekend perhaps I'll tackle the Fundamentals.
Anyway, I also made a quick little recording of Sportsman's Hornpipe - https://soundcloud.com/user-889775496/sportsmans-hornpipe-wout-thirds (https://soundcloud.com/user-889775496/sportsmans-hornpipe-wout-thirds)
It's in A dorian, and ending on the A bass + C major chord always sounds... wrong, so this has always been my go to tune for testing out a thirds stop. It seems to work. I run through all the chords with the chords in (order should have been G C D B, D C A E) first, too.
So... what have I learnt... well, I guess what I've learnt is that it is possible to add a stop to a melodeon. I know that probably sounds like a cop out but it's apparently what I have done, and I can hardly believe it. I can also take out all the bits and tape over the hole and be mostly back without it, too, so, that's cool. I should probably sort out a better fixing for some of the parts - the static slide parts are held in place with double sided tape, one of the block mounts has a spacer added while the other hasn't, so, should probably add one there, and I have a lot of hoovering to do. I've spent all this time working on it and barely any playing with it, now that I've actually done it that it hardly feels like I have even succeeded.
I wouldn't have considered doing this without all the advice provided in the thread, so, thanks to all who posted that (and for the encouragement). I hope that the photos and log of the experience is helpful or interesting to people, and if there's anything that I could elaborate on, let me know and I can try to do so when I try adding a second stop, whenever I muster the energy for that. I'll try and check the tuning, I suppose, as I'm taking the box to the local box clinic to have my D/F# swapped for an F/F#, a change that makes a lot more sense when you have, you guessed it: a thirds stop.
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As the most cack-handed person in the world I never cease to be amazed by the technical and manual skills of melnetters so I'm mega impressed with anyone doing this sort of stuff for the first time. Also, isn't it lovely that the box fettlers take the time and effort to share their knowledge freely and fully.
I have two 8 button D/G boxes - the Saltarelle L'Elfique and Hohner Pressed Wood, so one with stops and one without.
I much prefer the major/minor chord solution that doesn't require a stop on my Hohner, i.e. to have thirdless chords for A and B chords. Microbot replaced the thirds with an extra root/root octave or 5th (not sure which) when he put my Hohner together for me. So....if I'd have been you Gena, I'd have replaced 2 reeds rather than hack my box up. Actually, that's a complete lie - I'd have asked one of our expert repairers to do it!
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Well done Gena!
It has been very interesting to read your account and see all your photos. You will have learned a lot by doing this and also helped others who may be contemplating similar modifications. I especially like the way you approach the various tasks a little bit at a time ensuring that, as far as is feasible, you have an 'escape route' back if things start to go wrong.
...So, at least until that block breaks back in half again....
I think the problem is that the timber you have used for the block is soft pine with a relatively wide-spaced grain, which will be prone to breakage in such a small block, especially with the repeated stresses transmitted along it from the screw-thread shaft of the mushroom stop.
My advice would be to use a hard wood such as beech or ramin which has a closely spaced grain and will be inherently much stronger.
The block which holds the reed block clamps is beech - school desk, or kitchen chopping board timber.
Ramin is often used for decorative mouldings, picture frame kits, etc.
Perhaps you can find a small offcut or waste piece from somewhere? (try a picture framing shop for an offcut)
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I much prefer the major/minor chord solution that doesn't require a stop on my Hohner, i.e. to have thirdless chords for A and B chords. Microbot replaced the thirds with an extra root/root octave or 5th (not sure which) when he put my Hohner together for me.
Yeah, I think that's a really nice middle ground that someone should definitely consider because it might actually give them everything they want - you really want to go the route that gives you the best result for what you're playing. I taped off the 3rd on the B major chord on my first box, and adding an extra note to bulk up the sound makes a lot of sense if you never end up wanting it un taped.
But, for me, I've slowly grown a longing for pretty much every chord that I've got going on, as well as some of the ones I haven't... and I think I would miss the major chords in the places that I do use them - eg now I love the B major! But, I'm also looking to play around with keys I really probably shouldn't be, like C, maybe a bit of D minor, and a peppering of A major, mixolydian and natural minor. Obviously a sensible person would just get a CF but, well, I think this thread is a testament to the fact that I am not sensible.
I think the problem is that the timber you have used for the block is soft pine with a relatively wide-spaced grain, which will be prone to breakage in such a small block, especially with the repeated stresses transmitted along it from the screw-thread shaft of the mushroom stop.
Yeah honestly it's just a piece of wood that I have and cut a corner off of. Not really best practices, I'll admit - I guessed at which orientation might offer the greatest durability for drilling, and I was close! I almost got up to size! I thought about getting a plastic block and seeing about plastic welding the two materials together, but I wasn't sure how it would get on with the stop rod's thread. Anyway, I'll heed that advice, especially after the battle with the reed block clamp block, and go hunting for some more appropriate material to replace the block with; most of the wood stock I have is ratty odds and ends. I'm not seeing a lot of options that I can get to (easily) locally for in house picture framing, but a few leads I can have a go with. One option I could look at though is buying turning blanks, as they seem to be readily available in both wood types you mentioned, and roughly already on the order of being the right size. So far, this endeavor has cost me, fiscally at least, the stop plungers (http://www.cgmmusical.co.uk/CGM_Musical_Services/Melodeon_Stop.html#2) from Charlie and the £2.65 piece of plastic that I still have most of left. Investing in some mail order wood would be a small price to pay - the most valuable thing has been the information though. Well, that and the hand drlil, that thing's been my faithful ally.
Honestly throughout the whole process I was convinced I would try to move the rod and it wouldn't budge - every time I tried to move the slide with anything else it felt almost impossible. It's really perfectly fine though, now that it's got the correct handle on it.
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Hardwood would have been a better choice for threading.
PM your address and I can send you all sorts of hardwood offcuts.
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First of all, thanks Gena for this very detailed documentation (and congrats).
One thing I still don't entirely understand is how there isn't a huge air leak from the hole made for the rod. I know there's a rod going through the hole, but everywhere else in the box there are countless gaskets etc. and here they're suddenly not required.
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It is Stiamh! If you took the stop out and left the hole open the air would come flooding out, and in.
With the stop in place there will by a tiny amount of leakage, because of a close fit of the stop rod in the hole, and the relatively small size of the rod and hole.
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One thing I still don't entirely understand is how there isn't a huge air leak from the hole made for the rod. I know there's a rod going through the hole, but everywhere else in the box there are countless gaskets etc. and here they're suddenly not required.
There will be a slight air leak around the stop shaft, but it is barely noticeable even under high bellows pressure. Air leakage is proportional to the cross-sectional area of any gap. The cross-sectional area of the annulus between the shaft and the wooden block and end frames is really very small indeed. Contrast this with the potentially large cross-sectional area around the bellows frame if the bellows gasket were to be missing or removed.
Here's a rather crude set of calculations but the general point can be made.
1.
Stop shaft dia (say) 2 mm.
Cross-sectional area ∏r2 = 3.142 x 1 x 1 = 3.142 mm2
Diameter of hole for stop shaft (say) 2.2 mm.
Cross-sectional area ∏r2 = 3.142 x 1.1 x 1.1 = 3.802 mm2
Therefore cross-sectional area of annulus is 3.802 - 3.142 = 0.6598 mm2 (A)
2.
Now consider the bellows frames with dimensions, say of a Hohner Pokerwork, approx. 150 mm x 280 mm
Total perimeter of bellows frame (both ends) is (150 mm + 280 mm) x 2 x 2 = 1720 mm
Assuming the same gap as previously, if the gasket were to be missing: 0.2 mm (probably a conservative estimate).
Therefore the cross-sectional area of the gap of the bellows frames with no gaskets is 1720 x 0.2 = 344 mm2 (B)
3.
Conclusion
The air leakage around the stop shaft is very much less than the potential leakage around the bellows frames with no gaskets:
0.6598 ÷ 344 = 0.001918 (approx 0.2 %)
Which also demonstrates why a faulty or worn bellows gasket can have such a deleterious impact on the air tightness of a melodeon.
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It is Stiamh!
Just by way of explanation, Theo is contradicting an erroneous statement I made and deleted after about 20 seconds (having thought about the matter a little) - evidently not quickly enough to escape notice! Thanks, Theo.
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Thanks Theo & Steve, this makes a lot of sense!
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In addition, when the stop is right down the stop 'button' covers the annulus and when the stop is right up the internal block covers the annuls thus reducing even further the potential loss of air.
Posh boxes with stops usually have a small leather washer on the bottom of the stop 'button'.
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Easily sorted - make two little leather washers to fit on the stop rod, inside and outside, Castagnari style.
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The stop rod I have has very subtle ridges down its length, and when running it through the hole, it makes a cute little vvzzzzsht noise from how close a fit it is. Test fitting it in advance gave me a lot of confidence that I wasn't going to squeeze the bellows and have it shoot out or anything, but it was hard to believe before I saw it. Gives me an idea, actually, maybe I should try and document that somehow, since it would have helped me.
Anyway, Eshed, McGrooger, Stiamh, and especially Winston! I'm very glad to hear that people have appreciated the tale. I still have another stop to add, so, I'm more than willing to take on board feedback or take a picture of something that I did. I mean, on show mostly are just the ideas I had to solve my particular problems, so, hopefully people will let me know if I'm doing anything egregious. I've wanted a thirds stop for quite some time!
PM your address and I can send you all sorts of hardwood offcuts.
If my plan A doesn't work out, I shall do just that, thank you for the kind offer!
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I have a suggestion about drilling that hole. I would find it easier to use a power drill. Ideally on a floor standing pillar drill, or failing that with a hand held power drill with a nice controllable low speed. Maybe this is what you did, but I understood that you had used a hand powered drill.
Also on the drilling I think you will find it easier to drill a pilot hole, and then go straight to the finish size drill. Even better would be to finish with a drill that is .1 smaller that the stop shaft. That way you get a very snug fit.
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There are several versions of this https://www.amazon.co.uk/dp/B0001P19PO/ref=asc_df_B0001P19PO56252480/?tag=googshopuk-21&creative=22110&creativeASIN=B0001P19PO&linkCode=df0&hvadid=223168629794&hvpos=1o3&hvnetw=g&hvrand=14489010104604052102&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9045831&hvtargid=pla-421516047083&th=1&psc=1 (https://www.amazon.co.uk/dp/B0001P19PO/ref=asc_df_B0001P19PO56252480/?tag=googshopuk-21&creative=22110&creativeASIN=B0001P19PO&linkCode=df0&hvadid=223168629794&hvpos=1o3&hvnetw=g&hvrand=14489010104604052102&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9045831&hvtargid=pla-421516047083&th=1&psc=1)
Which is a substantial improvement on a hand held drill, and a good deal cheaper than a pillar drill.
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There are several versions of this https://www.amazon.co.uk/dp/B0001P19PO/ref=asc_df_B0001P19PO56252480/?tag=googshopuk-21&creative=22110&creativeASIN=B0001P19PO&linkCode=df0&hvadid=223168629794&hvpos=1o3&hvnetw=g&hvrand=14489010104604052102&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9045831&hvtargid=pla-421516047083&th=1&psc=1 (https://www.amazon.co.uk/dp/B0001P19PO/ref=asc_df_B0001P19PO56252480/?tag=googshopuk-21&creative=22110&creativeASIN=B0001P19PO&linkCode=df0&hvadid=223168629794&hvpos=1o3&hvnetw=g&hvrand=14489010104604052102&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9045831&hvtargid=pla-421516047083&th=1&psc=1)
Which is a substantial improvement on a hand held drill, and a good deal cheaper than a pillar drill.
I have one of those and they are for drilling holes in a wall or centred on a pipe. Not much use for drilling precision holes where you want them. I also have one of these which is quite a good (cheap) substitute for a pillar drill, if you have a mains drill, esp for light occasional use... I was unimpressed by it initially, but having used it a good few times find it perfectly adequate...though your drill needs a variable speed control and obviously a way to lock the power on.
https://www.powertoolsdirect.com/clarke-cds1-drill-stand?gclid=Cj0KCQjw9ZDeBRD9ARIsAMbAmoaNdIOeTCTxaPOznKJjt17GSRpGjQwcV95aaPPDMunSR92nXQ2BUxgaAvhxEALw_wcB
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I'd have a go at this, if I could fit it into my cupboard!
www.ebay.co.uk/itm/pillar-drill-Meddings-Single-phase/192690984744
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I have a suggestion about drilling that hole.
I'm not sure, honestly, I quite like a good hand drill. Well, more like Pin Vise, I guess - you can see if in several of the photos - in case anyone is uncertain, I'm certainly not using one of those hand cranky type things. I feel I have more control with it and can do things at a snail's pace, so can usually fix any problems (such as the hole drifting) before they're 'done' so to speak, and there's only ever as many rotations of the bit in the hole as I want . If this is in reference to the alignment, idk, I think in this case I failed to accurately clamp the wood block and it was in a slightly different place than it should have been. which I can believe because the plastic can be really very flexible, and then splitting and the final process of getting it up to size didn't help.
Going electric and having fewer jumps from pilot to final size to cut down drift - that's definitely something I'll consider when I come to replace the block with a better piece of wood. Should I worry about the grain direction particularly? Also I guess I'll have to figure out how to scour off the existing block without destroying the very thin plastic underneath. If I can manage that, I may cut the block slightly oversize, drill the hole, and slowly adjust the sides down until its perfect, and only then secure it to the slide.
I also think I'm going to release myself from my no power tools on the melodeon rule when it comes to removing the other part of the block mounting wood. That, and buy a proper chisel.
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... when I come to replace the block with a better piece of wood. Should I worry about the grain direction particularly? Also I guess I'll have to figure out how to scour off the existing block without destroying the very thin plastic underneath.
Since the main forces, up and down, are going to be perpendicular to the stop shaft axis, you want the strongest wood direction, which is along the length of the grain, to also be aligned along the stop shaft axis. Therefore I would recommend drilling and screwing into the end grain of the wood block. If you are using a hard wood such as beech, drill a pilot hole fractionally undersize first and then ease the stop shaft into it a bit at a time and then backing off and clearing the swarf/dust so that the shaft gradually cuts its own thread.
If at any future time, the stop shaft should become loose in the wood block, an effective remedy is to put a couple of drops of superglue into the hole, using a cocktail stick to quickly smear it round the inside of the hole. Then re-screw in the stop shaft before the glue has completely set. The glue will form a firm coating inside the hole into which the stop shaft will re-cut a thread, but will still allow the shaft to be unscrewed as needed.
(This works for loose bellows pins too!)
If you are concerned about removing the remains of the old block from the plastic slider cleanly, do you not have sufficient plastic sheet left so that you could make a new slider?
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If you are using a hand held power drill and the main worry is drilling at an angle, stick an old CD flat on the surface and the reflection will keep you straight. There's even a hole in the middle to drill through. A bit of blue tack will hold it in position if necessary.
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Steve has given the scientists answer. The practical woodworker would know that wood splits most easily along the grain and that drilling a hole into end grain and inserting a tight fitting screw has a wedging effect which will tend to split the wood along the grain. The strongest direction for holding a screw is at right angles to the growth rings.
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Yes - I know that. But it depends on the wood you are using, carefully drilling the pilot hole of the correct diameter, and being gentle with the initial threading of the stop shaft into the hole. Beech should be OK.
But if you are concerned about splitting then perhaps you should drill and screw transversely into the grain. I guess in this particular usage, the screw thread and the fact that the wood block is glued to the slider will help reinforce the block against subsequent splitting due to repeated movement.
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Probably the most used and most useful piece of advice I took away from Emmanuel Pariselle's melodeon building courses I attended was to wax the threads of screws in cases like this. Just some ordinary candle wax will help the screw cut its thread without causing other problems.
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I was given similar advice 50 odd years ago by an old woodworker, only he recommended soap. Although, in that instance, it was to ensure that the screws came out easily after being in situ for many years.
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Every screw in my hand built one-rows is waxed. I use Russian tallow, not Vegan friendly as it's made from melted cows, but it does the job.
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Screwing into end grain also gives the poorest grip.
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Screwing into end grain also gives the poorest grip.
Yup!
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Screwing into end grain also gives the poorest grip.
Yup!
<Rolls over with legs in the air. :-[ >
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There's a place here for engineering plastics. Dimensionally stable, self lubricating and easily worked. Not traditional granted but the slides Gena has used are plastic so why not the blocks?
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So, update! I ordered some turning blanks (for pens) that came with 4 pairs of different sorts of wood, including Ramin, and Beech, and also some American Tulipwood. Removing the old block from the slide was not a big deal, honestly the epoxy glue peeled off of the smooth plastic fairly easily. I don't think that will happen in normal operation because the flex of the slide between the attaching block and the reed block will likely absorb any wiggling. The wood sampler selection cost me around 6 pounds, and gives me lots of play with, so, I'm quite happy with that.
I used the Ramin to create 2 new blocks, and instead of epoxying the blocks on and then drilling the holes, I drilled the holes first. I drilled the holes only to 3mm this time, and tried waxing the threads of the stop rods, which did let me thread them in to this wood, and the blocks didn't show any signs of exploding. I re-taped up the inside of the bass end and epoxied the blocks on with the rods inserted, all in situ, giving little tweaks to the rod left/right/up/down etc to try and account for any unwanted off angle, and that seemed to work. Since the margins between rod block and slide were greater, I used more glue, so naturally there was a lot of glue leakage, all caught by the tape thankfully, and the rods are much more straight up/down. Epoxy is a very good space filling glue, so, I figure that this will be fine.
You'll note that I'm using a lot of plurals - I made my Fundamental slide and added that, too, so now I have 2 bass stops on my melodeon! Removing the needed section of mounting block was much easier this time - I allowed myself to use the power drill to drill the initial holes to remove material, and I also bought myself a narrow wood chisel, which the local hardware store guy game me a deal on because it was a bit marked up. The chisel made light work of splitting the grain and removing the material. The Scalpel though still seemed much better for whittling away material across the grain. When fashioning the slide, I drilled & expanded to 4mm holes, took the protective coating off of the plastic and positioned the slide on the reed block. I marked the plastic with 8 lines, like an *, to the edges of the actual hole in the reed block (since I could see through to it underneath), aand then used my 3mm tungsten carbide cutting head in the dremel to carve out an octogon to those points. I clamped the dremel in place and moved the plastic around, holding it taught in my hands. I then followed up with the Dremel's narrower sanding tool to round them out: It was much easier to put the slide in place, eyeball which way the hole needed to go, and circling it out there by eye, at least versus my previous method of trying to encourage the drills. Drilling the plastic really like to catch it and spin it out: as it's so thin, it's difficult to clamp it down and work on more than one area of it without just having it flex or otherwise act out. Plus, because of the axial grinding I did this time, the holes in the slide also needed less finishing work as a result, which was a bonus. There was really nothing massively different about the results of what I did vs the pictures I have already posted, but the way I achieved the goals felt like a lot less effort had been expended on my part.
Fundamentals slide seems to work, as does the thirds slide. I'm really pretty happy about this change as it's going to let me do a lot more with this instrument than I could otherwise - having the low fundamental stop helps me feel a lot better about subbing a bass note in for a missing melody note. I'll need to spend some time experimenting with them both.
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Well done, Gena. I think there'll be quite a few blokes who have been used to working with hand tools etc who wouldn't take a job like that on.
(Not being at all sexist there, as I'm perfectly sure that there are more males in that position than there are females!)
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For maximum strength and to minimize the chance of splitting, I would say make your own block material laminating slices of hardwood(s) oriented "cross-grain". Strong, artistic if you care to alternate dark/light woods (walnut and maple) and highly resistant to splitting.
Just an idle thought...
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... make your own block material laminating slices of hardwood(s) oriented "cross-grain"...
I think it's been done before. It's called plywood. ;D
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Just to give a sense of finality to adding bass stops to my Black Pearl, here's some photos of the new stop blocks and the 2nd plunger. The Fundamental stop has a bit more travel in it, but that's fine, the holes are bigger anyway. The stops are positioned evenly, however the button for clipping the bellows strap shut is not, so, makes things look a bit uneven.
Additionally I used both stops when playing for October 2018's tune of the month, the Hesleyside Reel (http://forum.melodeon.net/index.php/topic,22890.msg274947.html#msg274947). I think some of the bass reeds could do with tuning but not really as a result of this process, but that's something I'll try and investigate myself later.
Also, due to posting activity in it, I read a thread about the Castagnari Giordy. Due to its limited size, it uses 2 notes for its chord buttons. But, it apparently uses the 3rd and 5th (http://forum.melodeon.net/index.php/topic,16993.msg208408.html#msg208408), meaning to play the full chord, you simply play 'block' chords, so, the fundamental and chord button. This is a pretty weird way to have your chords work but does present a variety of interesting options, as the note make up becomes:
G/D chord: B+D / F#+A
C/C chord: E+G / E+G
D/A chord: F#+A / C#+E
B/Em chord: D#+F# / G+B
So that can clearly allow for some interesting combinations to form non standard or partial chords, especially for when you're playing with others. You can easily see in there D draw + G+B draw for a draw G chord, and B press + E+G press for a E minor press, as well as D chord + A chord draw for a F#+A+C#+E = F#m7... the list goes on, as it always does. And this is all at little cost if you're already playing mostly block chords for a tune.
Of course, to use a slide under the reed block, your reed plates have to share the tonics and fifths, maybe some do, I neglected to check, but, I imagine they probably don't in my instrument but next time I have it open, I'll check. I can see why Benammi Swift had his instrument modified to have a lot of bass stops for the individual notes (talked about in this thread starting here + posts from the man himself (http://forum.melodeon.net/index.php/topic,21624.msg260355.html#msg260355)) - it's a very interesting concept: I wish we had more control over all the reeds we have in our bass ends, or at least that the mechanisms to control them didn't take up so much space.
I've also learnt that Carini's (http://www.carinidena.com/) do seem to have a lot of coupler components etc on their site but it's all mostly indecipherable to me, both linguistically and mechanically.