davewhite
Luthier / Guitar Maker
Luthier
Aemulor et ambitiosior
Posts: 3,548
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Post by davewhite on Feb 22, 2017 8:08:49 GMT
"Never knowingly under complicated" should be your motto Rob. If you had leoroberts there as your assistant there would have been a lot of whistling I suspect  Who'd be a luthiers dog  |
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R the F
Luthier / Guitar Maker
Posts: 1,135 
My main instrument is: bandsaw
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Post by R the F on Feb 22, 2017 8:25:12 GMT
Who'd be a luthiers dog I'm expecting a visit from the RSPCA Acoustic Soundboard Members Interest Group at any moment... |
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leoroberts
C.O.G. 
Posts: 26,145
My main instrument is: probably needing new strings
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Post by leoroberts on Feb 22, 2017 9:48:26 GMT
"Never knowingly under complicated" should be your motto Rob. If you had leoroberts there as your assistant there would have been a lot of whistling I suspect Who'd be a luthiers dog All f-f-f-f-fixed  |
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R the F
Luthier / Guitar Maker
Posts: 1,135
My main instrument is: bandsaw
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Post by R the F on Feb 23, 2017 20:40:56 GMT
Things went quite well today. If I don't seem to be making very rapid overall progress, I have to confess that I'm also trying to earn money by mending and polishing furniture so bear wiv...
I noticed the other day that davewhite , one of my several gurus, used lime for his end-block. "Aha!", I thought. "Of course... There's no point in using pretty wood - or even structurally strong wood - when it's quietly doing a fairly easy job in the dark right at the far end of the box." So I found an old table-top made of something very light and nondescript which I think is probably tulipwood. Tulipwood is what I understand to be the American name for Poplar or some such innocuous timber - though I'm happy to be put right on this. Anyway, it got the job and here it is:
or, at least, that's one side of it - the side that will be stuck to the inside of the rim and will join together the two ends of the sides. Again following blindly where Dave leads I will be sticking a bit of bling to it which the aforementioned sides will butt up against:
If you don't recognise that as laburnum by now, then you haven't been doing your homework. I'm going to be bold and not put any neat little strings between the sapele side and the laburnum end-graft, thus:
At the other end things will be even simpler:
What I hope you will also notice is that the ends of the sides have been neatly trimmed and I have managed to snatch the beginnings of a guitar from a writhing mass of gluey veneer. Both top and bottom edge will need sanding down to precisely the correct profile but I have checked that there is indeed enough meat left to do that and to still match the plans. That's why I am quite content today - all f-f-f-f-fixed!
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R the F
Luthier / Guitar Maker
Posts: 1,135
My main instrument is: bandsaw
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Post by R the F on Feb 28, 2017 8:54:21 GMT
Having glued one end together, it was time to glue the other end. This would be slightly more complicated. The head block was last seen looking like this i.e. full of metalwork:
I obviously had to remove the "bolts" in order to glue that side to the inside of the rim (sides) but what about the cross-dowels/barrel-nuts? Well, the plan is that it should be possible to remove/install them after the guitar is finished should there be some wear-and-tear issues I have not catered for. However, it will be tight: here is a drawing of the headblock from above with the cross-dowels coloured in pink/red and their exit route marked with a blue dotted line. You can see that, if things are slightly out of kilter, the dowel will jam against the inside of the rim and won't come out without "proper encouragement":
If none of that makes any sense, I wouldn't worry about it if I were you. However, I am not you so I am slightly wary of the potential difficulty. A second potential problem is the fitting of the ends of the "flying buttresses" which fly through space inside the box from the inside of the waist, where they will be securely anchored, to the head-block where they are can push into the head of the neck, as it were. Of course, it's much easier to make your housings before installing the block. This got me thinking about the buttresses themselves. davewhite uses carbon fibre rods (round) and in my last effort I used oak (square). This time I think I may inadvertently have used ash (which looks a bit like oak from many angles) but I decided to make it round in section so that I could drill the housings. I therefore set about turning some 10mm diameter rods from some kind of native hardwood:
(They're not as massive as they look here: 10 x c. 180mm.) I then drilled some holes in the block at what I hope is the right angle, 28o, (but you know me...):
Can you see the other holes in this (inside) side of the block by the way? That's because I have cunningly drilled the turnbuckle-bolt holes right through the block so that I will be able to accurately extend these holes through the rim once the block is glued in place. (If you are finding this a bit hard to follow, imagine what it's like to design the bloody thing and then work out the procedures to match! It's no wonder I make the occasional mistake. "Stick to standard guitar plans!" is my advice... "Never knowingly under-complicated..."!!) Anyway, Here's the resulting combination - not glued in place yet, of course:
(The other holes are still there, by the way; they just haven't come out clearly in the photo.)
It only remained to glue the block to the rim. This was a little critical since it dictates the precise position (vertically and horizontally) of the neck-adjusting metalwork. With this in mind I decided to take the sensible route: I glued it half at a time. In fact so far I've only glued half. Here is how it stands:
(The right part of the side may look bent and broken but it is, in fact, only bent - pushed out of the way for the time being to allow room for the cramps. It'll spring back when I let it.)
Before all this messing round with the head-block, of course, I had had to make sure that the contour of the top of the rim (sides) was more or less right. This provides the raison d'être for the sanding trough which I spent so long building earlier in the thread so we can hardly miss out the action photo which illustrates its use. This is me in my action-kit and amongst the detritus of what I had been doing before I did this:
Technically this is known as "shoving it up and down" - how appropriate for Shove Tuesday. The result should be a top edge which precisely meets the contour of the soundboard. However, I think I got a little over-animated once I knew the camera was counting down and a little fine-tuning will be required with some guides cramped on to the sanding trough. I'll do that once the head-block is attached. Here's another picture I seem to have taken:
Hope you like it!
Rob
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leoroberts
C.O.G.
Posts: 26,145
My main instrument is: probably needing new strings
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Post by leoroberts on Feb 28, 2017 9:20:42 GMT
I won't pretend that I am understanding even 1/10th of the technical stuff you're writing about here, Rob - but it sounds mind-blowingly complicated and looks excellent!
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ocarolan
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Post by ocarolan on Feb 28, 2017 10:19:53 GMT
Brilliant thread is this, Rob. Enjoy yer pancakes!
Keith
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R the F
Luthier / Guitar Maker
Posts: 1,135
My main instrument is: bandsaw
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Post by R the F on Mar 1, 2017 8:34:41 GMT
Pancakes a complete success though/since I had no part in their making. (I, however, nipped to the Co-op for smoked salmon, cream cheese, spinach and lemon, all of which contributed hugely. Actually, I had to return to the Co-op because I had not got enough salmon but you wouldn't expect me to get it right first time, would you?)
Earlier that same day I had been in the workshop gluing the other side of the rim to the head-block, thus completing the rim. Here it is all cramped up:
Once I felt it was robust enough to suffer shoving up and down, I continued to sand the top profile - but notice the difference this time:
That's it! Guides to keep it precisely on the straight and narrow. The problem had been that even the slightest lateral straying from the line caused the corrugation to narrow as its sides were rubbed away. I also discovered that the join at the neck end, where it is critical to be accurate if the adjusting mechanism is to work, had managed to get itself slightly out of the vertical. An act of god, I reckon. (Me, avoiding responsibility, davewhite ?!) This means that I had to put considerably more weight on the right (as you look in the picture above) in order to bring it up straight again. Luckily - or did I plan it? - there is still enough meat to allow for such misfortunes. Unluckily, the sandpaper is getting a bit tired in the areas that count and I still haven't managed to get it straight. On my list of things to do this morning...
I omitted to mention that while the glue was going off on the head-block, I turned my attentions to the raised lining of the sound-hole. You may remember it last appeared looking a bit rough and ready:
So I set about rounding off the sharp bits to make it look a bit more artistic. This does not, as it turns out, involve much artistry; it involves a good pair of glasses and some sharp chisels and scrapers and a steady hand and quite a lot of time if you don't want to end up with a ditch around your ring-fort. Well, we got there in the end without too much damage to the soundboard:
I'm not sure if that's the final profile but it's getting quite close and I've got a rim to finish off so it'll have to do for now... (Nasty old glue line in there though, isn't there? I don't suppose anyone will notice when it's all polished up.)
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davewhite
Luthier / Guitar Maker
Luthier
Aemulor et ambitiosior
Posts: 3,548
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Post by davewhite on Mar 1, 2017 9:34:51 GMT
An act of god, I reckon. (Me, avoiding responsibility, davewhite ?!) That would have to be a mighty fine act indeed as I don't believe in God. I do believe in acts of wood though and - as you have experienced too, acts of dog  Ah ... VPL can be vexing - just tell everyone that it's a technique that the old Cascamites used and is very tricky to get right Looking good Rob  |
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R the F
Luthier / Guitar Maker
Posts: 1,135
My main instrument is: bandsaw
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Post by R the F on Mar 4, 2017 9:54:55 GMT
This is a bit of a long shot and I don't really expect a big response but.... As a corollary to what I was saying about breaking up larger areas of soundboard into smaller areas to encourage high frequency harmonics, I have been drawing all sorts of potential finger braces on pictures of the soundboard without coming to any conclusions... so I was wondering if any of you builders have any thoughts as to which area I might have a go at (from the top: red, black, blue or green - though they don't come out very clearly as different colours on here) and whether it's enough just to do one side or mirror image on both sides and exactly how I might have a go at them? You'll notice I haven't included the severely arched/corrugated/cylindrical areas since I don't expect them to be doing too much responding anyway. (I do, of course, reserve the right to ignore all suggestions if I think of something myself!)
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Post by nkforster on Mar 4, 2017 12:30:50 GMT
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Who'd be a luthiers dog 
Jo whoever he is.
