colins
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Post by colins on May 17, 2015 14:56:33 GMT
Well Leo the formula for fret spacing if building an normal temperament instrument with a 12 semi-tone octave is of course, : d = S - (s / ( 2 ^ (n/12))) where d = the distance from the nut, s = the scale length, and n = the fret number. This can be simplified by simply finding the distance from the nut to the first fret by dividing the scale length by 17.817. The second fret would of course be the scale length minus the distance to the first fret divided by 17.187, and so on for the rest. I usually do this in my head. Handily thought there are a number of fret position calculators in the interweb which will do the calculations for you. I don't bother with all this though for my standard scale lengths, I let the jig do the work for me. The fingerboard blank is double taped to a notched template. The body of the jig has a registration pin to fit the notches To cut the frets, simply register a notch onto the pin and cut the fret, move onto the next notch and cut the next, do this 21 times, (20 frets and the nut position) and a Robert's your mother's brother. Simples Colin
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leoroberts
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My main instrument is: probably needing new strings
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Post by leoroberts on May 17, 2015 16:58:35 GMT
Yeah, that's what I thought
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colins
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Post by colins on May 18, 2015 14:26:49 GMT
So far we have two fingerboards with fret slots cut, now as these are to be steel string guitars it is conventional to add a radius to the board, classical players of course manage perfectly well with a flat board, but steel string players can be a bit precious so better pander to their inadequacies and add a radius. I use a 16" radius on them, I rough this in with the drum sander and a series of shims that raise one side into the sanding drum, this gets me pretty close to the final radius as you can see in the second picture. The radius is then refined with a radius sanding block, I always do this sanding on the bed of my bandsaw which is perfectly flat. The radius is checked with a 16" radius press insert and the board checked for straightness along its length. This is really the start of the fretting process, making sure that the board is straight along its entire length at this point will save a lot of phaffing about later, though it will be checked again after gluing to the neck. Those paying attention, the swots among you, will have noticed that I cut the fret slots when the board was flat, and as I have now sanded a radius into the board that I will have sanded away part of this slot at the outside edges, some get over this process by cutting the slots deeper initially, but I like to have the fret slots even in depth across the finished board, so I re-cut the slots using a depth stop on the saw, this ensures that the slot is also at 16" radius and of even depth across the board. Will this make any difference to the final product? I don't know but it would bug me if the slot varied in depth across the board. Colin
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colins
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Post by colins on May 27, 2015 15:12:24 GMT
Sorry for the hiatus in the thread, got a bit distracted by my new bow. Martin here it is, a thing of pure carbon fibre beauty, quite, vibration free and the smoothest release you ever had! Anyway, back to the guitars, we had the fingerboards shaped and the neck scarfs cut and glued up, next step was to measure the required neck angle. I know that I want just under 2mm clearance at the bridge position to the neck face. I use a straight edege and the 2mm spacer on top of the guitar and using an adjustable protractor against the face of the guitar to measure the rquired angle, this is transfered to the heel stack which is then glued on to the neck at the 13th fret position. The necks are then rough shaped on the bandsaw. I then shape the necks on a spindle sander, to a semi-finished profile, and shoe shine sand the neck to 180 grit. I don't use templates for neck shaping, when it feels right it is. The front and back plates are added to the walnut neck and two necks are now ready to be fitted to their bodies. Oh, one other thing completed is adding the position markers, this was done against my will as I don't like them, but as the claro player wanted them I fitted the standard faux MOP ones to that fingerboard and as I don't know who is going to end up with the all English guitar I put my bone side/face markers on the bog oak board. Now back to the bow! Colin
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Post by earwighoney on May 27, 2015 15:29:07 GMT
Not sure I can click 'Like' on the most recent photo update after seeing Colin's fingers which were a difficult thing to see for someone as squeamish as myself!
Fine work on the guitars as ever.
I'm in agreement about the lack of fretboard markers, maybe down to spending most of my time playing nylon strings.
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colins
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Post by colins on May 27, 2015 15:46:44 GMT
Not sure I can click 'Like' on the most recent photo update after seeing Colin's fingers which were a difficult thing to see for someone as squeamish as myself! Fine work on the guitars as ever. I'm in agreement about the lack of fretboard markers, maybe down to spending most of my time playing nylon strings. I'm so used to them that I sometimes forget they are not the full nine yards! Colin
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Post by earwighoney on May 27, 2015 16:51:49 GMT
Not sure I can click 'Like' on the most recent photo update after seeing Colin's fingers which were a difficult thing to see for someone as squeamish as myself! Fine work on the guitars as ever. I'm in agreement about the lack of fretboard markers, maybe down to spending most of my time playing nylon strings. I'm so used to them that I sometimes forget they are not the full nine yards! Colin I'm like that but it's my head which isn't the full nine yards :/
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leoroberts
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My main instrument is: probably needing new strings
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Post by leoroberts on May 27, 2015 17:15:07 GMT
I love the idea (and example) of side markers on the fretboard. I have them on my DeFaoite instruments. I've just had a little check and realised that on Suki and Naomi they are there too - but so are fretboard markers. I'm not sure in what contorted position I would have to hold the instruments to make use of fretboard markers... Now, get on with the build colins. I'd suggest that you knuckle down but...
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colins
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Post by colins on May 27, 2015 18:07:49 GMT
Leo, the advantage, as I see it, of the ones I do is that they operate as both side and face markers, just a bit more discrete than the more usual style. I guess it's because I also played a lot of classical guitar, where of course people would point at you and laugh if you had fret-markers! I am a few knuckles down. Colin
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R the F
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My main instrument is: bandsaw
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Post by R the F on May 27, 2015 18:38:18 GMT
These ones are so discrete you can't actually see them when you want to...
... not quite sure what they're there for!
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colins
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Post by colins on Jun 2, 2015 17:16:30 GMT
So, (see I did it, I started a sentence with 'So'!) far (wait 'So far' at the start of a sentence is acceptable English, so I'll start again.) So far we have two wooden boxes and two sticks, time to join them together. To cut the mortise in the top for the neck extension I clamp the complex jig to the guitar and drill through the bolt holes into the body, the jig can then be bolted to the body. Using my small router and a guide bush I then rout the mortise incrementally to the exact depth of the extension. Repeat the process for the second guitar. At this point I drill through for truss rod adjuster access, I forgot once and wondered why I couldn't adjust the rod. I now need to put the inserts into the heel, to line up the inserts I use two registration plugs in the bolt holes and press the neck into position. The holes are then drilled and the inserts screwed in with a little epoxy, and squeeze-out cleaned up with some alcohol. When the epoxy has set the necks and bodies are bolted together and the cheeks of the heel (do heels have cheeks, I know my face does and my backside, but heels?) anyway, the heels are flossed with some 80 grit sanding belt until they are nice and flush with the sides and the neck is on the centre line. I also need to make sure that the neck is at the right angle so a straight edge is put onto the face of the neck and the gap measured at the bridge position, I'm aiming for a 2mm gap, and bingo, spot on, sometimes I amaze myself. Now we have two boxes with two sticks bolted to them, starting to look like guitars now, Oh, and I managed to put the correct neck on the correct body, wonders will never cease. Colin
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davewhite
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Post by davewhite on Jun 2, 2015 18:33:38 GMT
Me likey Or should that be - So . . . me likey Is "The Tree" top sounding promising when tapped - it certainly looks nice.
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colins
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Post by colins on Jun 2, 2015 19:18:47 GMT
Dave, "The Tree" does look amazing, even more so in hand. The tap is very promising, it has a rich 'chocolaty' sound. It does seem a little tight at the moment, I'll probably thin the perimeter a little, but I have high hopes for it.
By the way, your billet splitting was bang on, the top has zero run-out and is perfectly on quarter.
Colin
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leoroberts
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My main instrument is: probably needing new strings
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Post by leoroberts on Jun 2, 2015 22:05:14 GMT
colins, can you let me know: a) when you've finished 'em b) your home address c) your holiday plans. No particular reason, just being polite...
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colins
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Post by colins on Jun 3, 2015 9:30:27 GMT
colins, can you let me know: a) when you've finished 'em b) your home address c) your holiday plans. No particular reason, just being polite... Leo, I know you as a gentleman, so to answer your questions.
a) A while yet b) Fifth oak on the left, 100 acre wood c) Three glorious days in Halifax!
Colin
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