R the F
Luthier / Guitar Maker
Posts: 1,135 
My main instrument is: bandsaw
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Post by R the F on Aug 5, 2016 21:46:22 GMT
Before all the excitement I had fouled up by cutting the sides too short and gluing them to the tail-block. Well, I have now unstuck them and cut a new piece of mahogany(ish) - don't know what it is actually but it's not very dense - and shaped it to be my new tail-block. This was my plan if you remember:  ... and here is the tail block - the internal part at least - being glued to the strip of wood you'll see on the outside and whose name I can't remember:  The picture's a bit confusing because the tail-block is extremely oversized at this point and the strip of laburnum gives a better idea of the depth of the tail of the guitar. After attaching this piece, I glued maple constructional veneer (1.5mm) to the sides like this:  It suddenly occurred to me about now that what I was doing was what davewhite does as a matter of course in most of his builds and it really does make the whole thing quite straightforward. I don't suppose he stumbled upon it through making a mistake though. This is the unit I was left with all ready to be glued into place and to save a lot of trouble later:  Here it is being glued to one side of the rim:  And here are the results once both sides have been attached:   So there we are then. Saved the day and developed a new technique for the tail oojamaflip. Well, new if you discount Mr White. Nice to be back in the workshop, too, and no blood was spilt during the making of this post. |
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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 Aug 6, 2016 19:28:08 GMT
Just had a thought. The "Bryn Production" guitar weighs 1.927kg and is fairly conventional in terms of thickness of front, back and sides except that it employs laminated linings as in colins , which probably add a little to the weight as well as to the rigidity of the box. The "Beefy Bryn Flat-top" has plywood sides and a laminated back and weighs in at 2.625kg - considerably heavier but the theory was to add to the dead-weight of the supporting structure in order to allow the soundboard to produce more response. I am happy enough with this to be making another similar guitar, "the next one", with the same beefy sides and I was just coming up to having to buy the carbon-fibre reinforcements for the neck (not cheap) and the carbon fibre flying buttresses (not cheap) to transfer stress from the waist to the neck block when I had the aforementioned "thought". If I'm not trying to save weight, why am I bothering to spend so much on space-age materials when a good chunk of mild steel would do the same job. So what do you think? Steel bars to reinforce the neck and steel rod flying buttresses at about a tenth of the cost of carbon fibre? I will no doubt decide for myself, but can anyone think of reasons why I shouldn't? I'd appreciate your thoughts. |
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francis
C.O.G. 
Posts: 2,483
My main instrument is: Whatever I'm building...
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Post by francis on Aug 6, 2016 20:37:30 GMT
Martin's used to use either a metal 'T' or square steel tube (neither adjustable) as neck stiffeners - they're hardly truss rods! As for the steel inside - I'll leave that to others to comment on as it doesn't do it for me...  Just need to watch the overall balance of the instrument. |
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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 Aug 6, 2016 20:48:29 GMT
Martin's used to use either a metal 'T' or square steel tube (neither adjustable) as neck stiffeners - they're hardly truss rods! As for the steel inside - I'll leave that to others to comment on as it doesn't do it for me... Just need to watch the overall balance of the instrument. I don't mean to replace the truss rod, just the carbon fibre stiffeners. The "balance" of the instrument amounts to its being difficult to lift it off your lap! |
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francis
C.O.G.
Posts: 2,483
My main instrument is: Whatever I'm building...
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Post by francis on Aug 6, 2016 22:56:11 GMT
Martin's used to use either a metal 'T' or square steel tube (neither adjustable) as neck stiffeners - they're hardly truss rods! As for the steel inside - I'll leave that to others to comment on as it doesn't do it for me... Just need to watch the overall balance of the instrument. I don't mean to replace the truss rod, just the carbon fibre stiffeners. The "balance" of the instrument amounts to its being difficult to lift it off your lap! The CF stiffeners probably weigh in less than the timber you remove to fit them. The idea behind the internal CF to me is to reduce the body timbers to a minimum: top, back and sides, but I get the feeling that's not what your doing? |
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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 Aug 8, 2016 20:58:22 GMT
I made a little progress over the weekend, though I am lowering six dining-chairs at the same time. I started sanding down the top of the sides to fit the arch of the top by sliding it up and down my shaped sanding trough  but I lost interest after a while and had a look at the neck blank. I drew a picture of the headstock on the blank having glued some little ears on the side:  and, lo and behold, there's one of the dining-chairs in the background in case you doubted me. I've done some more today but the photos aren't back from the chemist yet so I'll write about it tomorrow. |
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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 Aug 9, 2016 21:42:17 GMT
I've been thinking about this business of carbon fibre and decided that I might get away with something I mooted a couple of guitars ago when trying to avoid spending all my savings on special luthier-price carbon fibre. I bought some square tubes (4 x 4 x 1mm walls), which non-specialist suppliers sell and are consequently a whole lot cheaper. You may remember the plan was to glue two tubes together to make up an 8 x 4mm reinforcement, two of which would run along the neck, one either side of the truss rod. Here's the plan and here they are glued together with Araldite:   I do slightly worry that, what with the three-part neck, the steel truss-rod and the double-carbon-fibre strip reinforcement, the neck loses all freedom to adjust itself to the pull of the strings and form a nice natural relief contour so I'm quite happy to lose a tiny bit of stiffness and not lose a few quid. The problem with using steel is that the same profile in steel appears to be considerably less stiff than carbon fibre so it's not just a matter of weight difference. The so-called flying buttresses are another matter; since carbon fibre is only of any use when it's under tension, I wonder whether it's the best thing to use where ability to counter compression is necessary. Still, in rod form they are cheap enough and will resist bending and will therefore do as good a job as a piece of oak, I suppose. I'm tempted to use a piece of oak, though. But that's all to come. Getting back to current progress, I routed out some grooves in the neck, to wit two groove 8mm deep and 4 wide each 3mm away from a central groove measuring 11 deep by 6mm wide. The truss rod is only 9mm deep but I lined the groove with a bit of thin felt to counter potential rattling and planned to cap the whole thing with 1.5mm of maple. Here are the grooves partially occupied:   The carbon fibre was glued securely in place with Araldite while the truss-rod was only itself attached at the heel, the maple cover being glued securely on top to keep it in place again using Araldite - other glues like Araldite are available. Here's a picture of it all cramped up, which shows nothing of any use at all...  ...except that I own a variety of different cramps. I don't suppose anyone follows this avidly enough to notice that this time I have decided to access the truss-rod from the head end. Previously, at least on flat-tops, I have taken the truss-rod right through the one-piece neck/neck-block right up to the soundhole and gained access through that. This always appears to me to be a neater solution since you don't need to start bothering about truss-rod covers and little screws and so on. However, the rod doesn't actually do anything once the neck thickens out at the heel and, more importantly, the wound third and fourth strings always seem to bear slight scars from my allen keys as soon as I start fiddling with the truss-rod. So this time I've turned it round and might even go for something like the ajlucas tasteful oval opening to avoid having to mess with those little screws. We'll see. Meanwhile, my mind has turned to the finish of the headstock and I've decided on a repeat performance of the last guitar with cross-grained laburnum. I like the look of it. It reminds me of well made furniture. Here is the piece I have made up:  and let's hope it looks better than that when it's finished! There's not much more I can say today except that the machine-heads arrived yesterday. This time they are German but almost exactly the same design as the Japanese ones I have used on the last two guitars. It's fascinating (to me, at least) how different a look they can have when they really are almost exactly the same design. Here's a nice big picture of them to end on:  |
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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 Aug 10, 2016 21:00:49 GMT
Things didn't seem to move very fast today despite good intentions. I began by slicing the excess wood from the back of the headstock. I don't trust the bandsaw to do this especially when it's got a quarter-inch blade in it which I can't be bothered to change over to a three-quarter so I opted for the Travis Perkins and a bit of sweat:   I then glued the piece of laburnum which I had previously prepared on to the face - I'm afraid it's another crush of cramps shot:  It's a rather sophisticated cramping caul, in fact, which involves a layer of cork and a layer of green baize because I always seem to be gluing a rather rough piece of wood on to the headstock for later sanding and it needs to be able to accommodate a bit of unevenness. And here's the result after a bit of trimming to shape and a bit of drilling:   And don't be fooled; those holes look pretty good but the other end of them (where they are narrower so that the pegs just fit through) have been completely botched and will need sorting out tomorrow - notice the use of the passive to deflect responsibility for the botching. I also spent some time dragging the sides up and down the sanding trough today. The top is done and ready to receive the soundboard but the bottom still needs quite a lot of dragging. No pictures. No video. So what's next (after de-botching the headstock holes)? I guess I'll finish shaping the headstock while I'm about it and then there's quite a lot of work to do at the other end in shaping the heel and block so that it'll receive the sides into slots with as little fuss as possible and then I'll have something a little like a guitar but without a front or a back. I'll have to make some flying buttress decisions quite soon, too, since they will end up in the heel block and I still don't have a perfectly clear idea of how they are going to connect to the waist. How exciting it all is, said Mrs Dalloway. |
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Post by ocarolan on Aug 10, 2016 21:43:12 GMT
................... How exciting it all is, said Mrs Dalloway. Indeed! I once had a guitar with the brand name Clarissa, but it wasn't at all exciting..... 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 Aug 12, 2016 22:23:52 GMT
Rather predictably, I sorted out the holes in the headstock well enough to be able to take a photo of the nasty side:  It was quite a successful recovery in fact. I'll even show you a side view to indicate that I've started shaping it in that dimension, too:  That was enough for that end of the neck for the time being because I know from experience that, if I finish things off too much whilst still working on the piece, they tend to end up rather the worse for wear and I have to start repairing things before they're even finished. So I switched to the other end: the neck-block. Unfortunately, I realised quite soon that my drawings of this had gone slightly awry. It all happened, I imagine, when I pushed the neck into the body by 18.1mm - the distance between fret 12 and fret 13 - and had to move the hole further into the body as a consequence. I somehow seem to have left the body 18.1mm too long and the neck block a similar amount too short in my drawings. Trying to get your head around that on a computer screen along with the exact angle that the neck needs to be canted back while a few feet behind you your 14-year-old seems to have most of Cottenham (a village in Cambridgeshire) visiting one by one and you're the only one who hears them knocking... well, it doesn't do much for the concentration so I had a lost afternoon at the very least. In the end I sorted it all out. I also finalised my plans for the so-called "flying buttresses"... I have decided to use CF for my flying buttresses - cellulose fibre. It's wood, actually. It's oak, to be precise. It comes from the top of this table which I modified for a customer about 7 years ago:  It's part of that end bit with the screws sticking out of it and here it is today:  with a screw sticking out of it! I've sliced a bit off the end and after this I discovered these pieces lurking inside the bit I'd sliced off:  They're about 10mm square by this time and, at only around 160mm in length, I don't think they're going to bend very much whatever the stress. They're also cheap. They also smell fabulous. Here's the plan:  We're talking about the bits that form this shape: /\ and connect the waist to the neck-block. They are "flying" in the sense that they are away from the soundboard (and the back) and will appear as struts inside the box. I'm letting them into the neck-block at one end and into the plywood side at the other and they will run near the soundboard and parallel to it, though it is in fact arched and they are straight. Here they are installed in the neck-block but not yet glued because there is quite a lot of work to do on the block and I don't want to do it with antennae sticking out of it:   I'm not sure they are quite low enough yet to avoid the braces that run up past the neck-block so you might see further modification at a later date. But not today. Today is run and I'm off to bed. |
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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 Aug 17, 2016 21:05:07 GMT
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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 Aug 18, 2016 20:08:22 GMT
Still stuttering forward. Today all I did was to cut a platform on top of the neck/heel-block to accommodate the neck-end of the soundboard. It's fairly critical that I make an attempt at the right angle here or it could throw things out of kilter and it also has to be arched very slightly to match the arch of the soundboard. Anyway, this is what it looks like:  Please ignore the cramp which is just there to keep things more or less straight. Please also ignore the fact that I continued the carbon fibre reinforcement right up into this block where it is doing nothing at all apart from making it more difficult to cut the platform! Then I cut little housings inside the waist to accommodate the ends of my flying buttresses. Not glued in yet but here they are in place:  All ready for gluing tomorrow morning. |
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francis
C.O.G.
Posts: 2,483
My main instrument is: Whatever I'm building...
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Post by francis on Aug 18, 2016 21:09:57 GMT
All very interesting - are you doing any further shaping to the neck before you glue up?
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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 Aug 18, 2016 21:33:14 GMT
All very interesting - are you doing any further shaping to the neck before you glue up? I'll probably trim it to near proper width because that's easier to do without a box hanging off the end. I've already trimmed the heel where it meets the box so that I don't have to do too much fiddling around there after it's fixed on. |
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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 Aug 19, 2016 20:11:10 GMT
If I'm honest, I hadn't necessarily planned to trim the sides of the neck down to size until francis mentioned it last night but, once I'd promised to do it, I thought I'd better start with that. So I did. It'll save doing it later and it is easier without the box on the end. However, even when the sides are fixed into their slots, the whole thing is still detachable if you follow the colins "don't glue your sides in" school of thought, which of course I do. So, having tapered the neck, I glued in the wedges but not the sides themselves if you follow. The point is that the sides will still move in their rather tight housings but will remain adjustable until the top and bottom plates are firmly glued in place; it's these that really hold the neck in place, the slots being locators rather than fixers. A picture may stop my wittering so here is the scene earlier this morning:  NB the flying buttresses are still only located in their sockets, not glued. So then it was time to turn to the soundboard. It's not actually got beyond this point yet:  Well, this morning I trimmed it to shape with a bit of spare around the edges and then drilled 2mm dowel holes through to where the bridge patch will finally end up; (you may remember that I had erroneously drawn a soundhole in the wrong place at an earlier stage so please ignore that):  I then set about carving the braces to shape first in their vertical/longitudinal dimension and, later, to make them a bit pointier (or even "parabolic") in their vertical/lateral dimension:  You may observe that, by the time Mrs RtheF came home from work, I hadn't quite finished this process so some are more curvaceous than others. Nonetheless, the long front legs of the spider, which stretch up past the hole, are more or less at their final height and I was able to test the positioning of the flying buttresses:  Despite appearances, there is a bit of daylight showing between the soundboard and the sides so not quite. the sockets in the neck-block will need to be sunk a little deeper so that there is no contact with the long braces. But a good day's work and, if I can rouse myself to do something tomorrow, I might make further giant steps towards that ultimate goal of a gold medal at Halifax; after all it's what I've been sweating and fighting and striving for for the last four years without lottery funding but with the belief that I could do it; and I'd like to thank my late parents and my coach if I had one and the whole guitar fraternity and, in fact, the whole world and why stop there - there may be a god even though They might not necessarily be on my side... Sorry. Here are some pictures:   |
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Jo whoever he is.
