Building an ARCHTOP Guitar - Page 2
May 10, 2010
As things tend to do when I'm making a guitar, something happened. Something else, I should say, since
the back already had the big error of being glued up wrong (see April 12 for details). I had gotten the
outer carve on the back about where I wanted it and decided to go ahead and start the inner carve. This
time I used my drill press -- instead of the router fixture I used on the top (see the last photo in March 4)
-- to drill the guide holes.
Same idea as the router
fixture: set the depth stop
so that the bit stops the
proper distance from the
vertical stop (the thickness
you want the back to be),
then drill holes all in the
(flat!) side of the back and
the bottom of the holes
will guide your carving
But what happened is that the depth stop slipped and before I knew it I had drilled two holes right through the
back. After I finished cursing I thought about it. I had three options: trash it and make a new back; say 'what
the hell,' patch the holes and proceed; or figure out some kind of decorative scheme to cover or incorporate
Then a deus ex machina solution presented itself to me. Paul Lloret built a duplicating router for
rough-carving archtop tops and backs. It works well, but it needs a template. I have here a decently-carved
but otherwise screwed up back.... of course, I'll make it a template, then I can do another one (correctly)
using the duplicating router! So I plugged the holes and whistled on my merry way. Here are the plugs, and
the ugly knot that helped convince me of this course of action:
So I finished the drilling and got down to some serious carving. For this phase I found that my
round-bottomed plane, though tiresome (and tiring!) to remove all this wood with, is nonetheless the best
way to do it. I started yesterday, and tonight I got from here
So now I'll refine this template and start the search for the wood for a new back. Maybe I'll go ahead and
use maple after all.....
June 10, 2010
Raising money for the remaining components... I'll be back.
August 30, 2010
That was a fairly long time, wasn't it? Had to sell an effects pedal (a nice Original Ross compressor) and I
went round and round with the E-buyer... Then I spent time making some wedding presents for my sister...
But now I have in hand new wood for the back and sides and most all the components I'll need.
But can I just say first, look at this wood!
The wood (though it doesn't look like it in the picture of the body blank) is completely consistently
flamed, every cubic inch. Same with the sides. The back blank is over an inch thick. The back
will eventually be just under an inch tall, so there's some room for planing it so that it will sit nice
and flat on Paul's duplicating router.
And here's the first (abortive) back in process of becoming the template for the router. I refined the
carve and sanded it nice and smooth; now I'm gluing it to a piece of plywood, clamping them both to
a stiffer piece underneath to ensure flatness. I'll cut out plywood surrounds and fill the gap with
wood filler or something so that the router's stylus won't hit any bumps or dips.
It was only after I had carved out most of the inside of the back that I realized it was unnecessary, since
the template only has one side. D'oh!
September 3, 2010
Then I cut a 3/16 plywood surround and glued it into place. I filled the gap with wood filler and
sanded until the edges of the mahogany template were level with the surrounding plywood.
So now there's a nice smooth transition for
the duplicating router's guide pin to
follow. In the router there are two bays;
one for the pattern and one for the maple
back blank piece to be cut. We'll put the
blank on a piece of plywood the same
thickness as the template's backing board.
That way the maple will be shaped with the
edges the same thickness as the template's
By the way, that mahogany has an amazing ability to change color, doesn't it? Different light sources and
October 14, 2010
I've spent most of my shop time the few months on another project, but now I'm making some
progress! I joined the halves of the back. And tonight I started the outside carve using Paul's
duplicating router. This is quite a machine:
Here is a general view. On the left is my template, on the right is the maple back-to-be. The black
semicircles are saw burns and are inconsequential; I made some very deep cuts to remove waste from the
outside edges to minimize the work the router has to do. The way this thing works is (A) is the stylus that
rides the template. It's a rod with a little wheel and can be adjusted up and down to control depth of cut.
(B) is the very large 'mantle' that the stylus and router are attached to. It is balanced like a see-saw, lightly
weighted on the near side to keep the stylus and router firm to the workpieces. It is basically stationary; it
rocks up and down as the pattern is pushed underneath. (C) is the sliding plate that the pattern and
workpiece are clamped to. (D) is a screw that moves the stylus and router together sideways across the
plate. The screw is operated by hand with a cranked wheel; the number of rotations determines how far
apart each pass is.
Here I'm halfway through an intermediate pass. It's cutting far enough down to start following the arch,
but not fully yet. It's not easy, but if you look carefully and get the contrast right you can see the upper
bout emerging. The cutaway 'horn' is just above and slightly to the left of the toggle clamp. Here you can
see the crank wheel that turns the screw that moves the router -- two turns moves the cut 1/4 inch or so,
then push the plate under and back, two more turns, repeat. It's sort of tedious (it takes about an hour to
do one pass), but it's WAY quicker and easier than hand carving. Of course you have to hand-carve the
template, but then you're set. I like it.
October 18, 2010
And here's a detail shot showing the
surface texture left by the router. This
will be where I'm starting from with
sandpaper and scraper.
And here's the completed product fresh from the duplicating router. Yes, it's the same piece of wood, just
different lighting. The jagged 'frame' is the edges that were clamped down in the machine and thus not
routed away. This is the product of around three and a three quarter hours of work. Hand carving
(especially wood as hard as maple) I would have barely made a start in that time.
Also evident in this photo: imperfect bookmatch!..Again! But this time it's the unavoidable result of
carving so far down to the surface. OK, now I see two good reasons to start from angled flitches
like the top and original back were: first, obviously, it reduces carving time and effort; but second,
there's much less wood removal to spoil the bookmatch.
October 21, 2010
I did some sanding on the back and bandsawed it to the outline. It's looking pretty good but it's a
job scraping/sanding that maple. I'm increasingly glad for the duplicating router. Then I decided to
play with the top for a while, and laid out my f-holes. They're a little oversized to allow for the
binding. I know I could have done with one template, but I wanted to see them both on the guitar.
Sue me. I started thinking about cutting these with a coping saw and I admit I'm a little intimidated,
but I guess I'll just take a deep breath and do it.
I swear, those don't look even to me. I've measured them every which way, and I know they are
accurately laid out, but something seems off... I'll give it some more thought before I begin cutting.
October 23, 2010
Ah, Saturday. Got a few things done. I cut the f-holes. I laminated the f-hole binding. And I shaped
one of the top's parallel braces. Quod erat demonstrandum:
The f-hole binding is WBW. I laminated it using Stewart-Macdonald's handy little jig called,
interestingly, a "binding laminator." The f-holes themselves were a little more challenging. I drilled
the top and bottom holes with Forstner bits (3/4" for the upper and 7/8" for the lower). Then I
used a coping saw for the main cuts, followed by a file and sandpaper. Getting the coping saw
blade hooked up and then unhooked with the blade through the hole was awkward though. I used
a bar clamp to compress the frame, but I'm sure there's a better and easier way. The brace was
just look-and-trim tedium, but I got it fitting nicely. I'll do the other brace and then glue them into
place after I do the f-hole binding.