There is the pragmatic side of the rosette -- actually doing the inlay into the soundboard of the guitar -- but there is the aesthetic side of it as well. Beyond the actual choice of tone wood for the top, the rosette is the luthier's signature. Consequently, I have been thinking about rosettes a bit lately, and if you'll pardon a bit of philosophy, I always come down on the side of simplicity. As a devotee of Fretboard Journal, those guitars with elaborate inlays for the rosette and headboard, do not much appeal to me. I can admire the skill (and it is much beyond me) but let's face it -- some are just gaudy.
Simplicity, for me, means nothing but wood (ok, and the BW perfling strips from LMI). So, the rosette I have planned will be a simple affair, just a BW perfling line, followed by 1/2 of padauk inlay, followed by a WB perfling line. There are two reasons for the padauk. One, I have some scraps and off cuts that I've rescued from the flood. It's the sort of thing that one can't bear to throw out, even if it has been soaked in pooh water, as my son puts it. Two, I think the color complements and off sets the redwood that I'm using for the soundboards. The perfling, with the white against the padauk, the black against the redwood, creates a border, and highlights it. It's an irresistible combination.
Beyond that, there is an embellishment I have been contemplating. Once the hardwood for the rosette is in place, it might be interesting to cut a channel in that, filling it with turquoise or another finely ground stone, drizzle it with CNA, then grind it smooth. I don't think I'd want to put it directly in the redwood, in part because I think the grinding might damage it. We'll see.
Wednesday, December 28, 2011
Tuesday, December 27, 2011
Radius Cutter
I found a little time to mess around in my shop this morning, and I came up with this radius cutter that I will use to cut my rosettes. I was able to get into the school shop, and we have a great band saw with a re-sawing blade. It cut the redwood like butter. I will begin work on the soundboard, beginning with the rosette. I have something in mind, but don't know how well it will work. I'll give it a whirl and let you know if it does. The construction of the radius cutter is fairly simple. I had some 1/4 inch oak scrap left over from the bench, so I cut a 1/4 in dado in the sides of the cuter, and at the same time, cut for the end pieces and the slide, but did them on both sides. The pieces are laid out on my bench.
The slide works fairly well. I took a section of what I'd cut for the end pieces, enlarged the dado slightly. I drilled a 5/16th hole for the blade, and squared it off with my 1/4 inch chisel. I drilled a 1/4 inch hole for the carriage bolt, then cut it in half with my gent's saw, pushing the blade up against one side of the dado. The slide is held in place by the carriage bolt, which pinches the two pieces against the interior slats, and the blade is held in place with a small shaped piece of the slat. It all pivots on a 1/4 metal pin that goes in the hole on the right.
The blade is made from an old jig saw blade. I did some very preliminary work on the grinder, but it will need some additional shaping. I have in mind a chisel point so I can turn it in both directions, and will work on some when I get up in the a.m. I should be able to do that without waking my wife and our guests. Even with the point only partially sharpened, however, it did cut a good groove in a scrap of birch ply, at about 1/32 of an inch wide.
Monday, December 19, 2011
Re-Sawing Prep
I did, however, put together what I will need to do my re-sawing. On the left, is a tall fence. I used it in making the raised panels for apothecary cabinet as well. I clamp the panel to it, then run it across my table saw with the blade set at a 15 degree angle or so. For re-sawing, I clamp it to the bandsaw fence, adjust the table so it is perfectly square to the blade, then back it away 3/16ths or so from the blade and slowly, slowly, slowly feed the stock. In front of it are my thickness calipers (will be buying a better soon) and a push tool. The push tool I put together from off cuts left from the bench. Next is the piece of redwood that I hope to re-saw, the template, and scrap perforated hardboard that I will tape over the re-sawed plates to protect them.
Sunday, December 18, 2011
Go Bar Deck & Molds
Yesterday, I fiddled around with a radius cutter, similar to the Lie-Nielsen tool, but I did not get anything approaching satisfactory results, so I set it aside. The next big projects, though I won't likely work on it much until after the holidays, will be the Go Bar Deck, the Mold, and a clamping station.
The Go Bar Deck should be a simple affair. I visualize a plywood base and a plywood canopy of approximately 24 x 24 inches. In the corner of each, a 3/8th or 1/2 inch threaded rod with a pair of bolts in each corner to hold everything together and allow for height adjustment. LMI sells the go bars (CLGO), but they are a bit pricey at about four bucks a pop. McMaster-Carr also sells 3/16 fiberglass rods at 5 foot lengths (8543K28) for about 2.50. I will go with the McMaster-Carr, and if they don't quite work out, will order from LMI later.
The base provides something to think about. It's easy enough to have a 1/4 dowel in the center to capture the radius dish, and a second (not through the dish) to keep it from spinning like a lazy susan. I have been wondering, however, should I make the base so it can serve as a sort of supplemental work station? It's not an original idea, but what I have in mind is a two level base, with one side covered with carpet remnant, the other bare or covered with sandpaper. The advantage would be a covered work surface that wouldn't mar the surface of the guitar while doing things like trimming bracing. It would also, so far as the go-bar-deck itself is concerned, make it a bit more convenient to attach the base. I will likely go for simplicity.
I have been procrastinating on the mold for a while, but have decided to press ahead at the next opportunity. I intend to do it much the same way that I did the blanks for the radius dishes. First, with a 1/4 spiral up-cut bit in my router, along with a brass bearing closest to that 1/4 inch diameter, I will trace the outline of the guitar into the MDF at approximately 1/4 inch depth. That will provide two things, the inside contour of the mold, and the outside contour of a clamping station as well as the pressure pads for the mold itself once complete. I will clean them up with the pattern bit. Then do it again until I have enough pieces to stack 4 deep on each side, or a 3 inch thick mold. I clean up the outside edges on the table saw. I will talk about the design of the mold as I built it, so I can use photos to illustrate, but it too is a relatively simple affair.
I use the clamping station for a variety of purposes, not least as a test when bending the sides or binding. It could also be used for a mold when bending sides with a heat blanket. I have never used that method, so won't attest to it, but I have seen it illustrated a number of times. I built my first on Sloane's advice, where the sides are essentially boiled soft, then quickly clamped in place. I never found that workable, but like his model, I use spring loaded clamps when I want to use it for actual clamping -- e.g. letting a side rest after bending freehand. Here again, it's a relatively simple affair, but I will talk more about the design as I build it. I figure, if you're building the molds, might as well build the clamping station at the same time and save some scrap.
In the meantime, I have a piece of redwood that I have been using for guitar tops. Since the parts have still not come in for my band saw, I have set up a time Tuesday to use the one at the school where I administer to re-saw some plates. The responsible dean found it all very amusing, the Provost in the wood shop, and wanted to be there with camera should I happen to cut off a finger. I can get a start on some sound-boards while slowly putting everything else together. I've made the jointing jig, and I will likely use the zip flex pearl from LMI for the rosette itself, along with some perfling material. I'll likely order all that after the holidays.
The Go Bar Deck should be a simple affair. I visualize a plywood base and a plywood canopy of approximately 24 x 24 inches. In the corner of each, a 3/8th or 1/2 inch threaded rod with a pair of bolts in each corner to hold everything together and allow for height adjustment. LMI sells the go bars (CLGO), but they are a bit pricey at about four bucks a pop. McMaster-Carr also sells 3/16 fiberglass rods at 5 foot lengths (8543K28) for about 2.50. I will go with the McMaster-Carr, and if they don't quite work out, will order from LMI later.
The base provides something to think about. It's easy enough to have a 1/4 dowel in the center to capture the radius dish, and a second (not through the dish) to keep it from spinning like a lazy susan. I have been wondering, however, should I make the base so it can serve as a sort of supplemental work station? It's not an original idea, but what I have in mind is a two level base, with one side covered with carpet remnant, the other bare or covered with sandpaper. The advantage would be a covered work surface that wouldn't mar the surface of the guitar while doing things like trimming bracing. It would also, so far as the go-bar-deck itself is concerned, make it a bit more convenient to attach the base. I will likely go for simplicity.
I have been procrastinating on the mold for a while, but have decided to press ahead at the next opportunity. I intend to do it much the same way that I did the blanks for the radius dishes. First, with a 1/4 spiral up-cut bit in my router, along with a brass bearing closest to that 1/4 inch diameter, I will trace the outline of the guitar into the MDF at approximately 1/4 inch depth. That will provide two things, the inside contour of the mold, and the outside contour of a clamping station as well as the pressure pads for the mold itself once complete. I will clean them up with the pattern bit. Then do it again until I have enough pieces to stack 4 deep on each side, or a 3 inch thick mold. I clean up the outside edges on the table saw. I will talk about the design of the mold as I built it, so I can use photos to illustrate, but it too is a relatively simple affair.
I use the clamping station for a variety of purposes, not least as a test when bending the sides or binding. It could also be used for a mold when bending sides with a heat blanket. I have never used that method, so won't attest to it, but I have seen it illustrated a number of times. I built my first on Sloane's advice, where the sides are essentially boiled soft, then quickly clamped in place. I never found that workable, but like his model, I use spring loaded clamps when I want to use it for actual clamping -- e.g. letting a side rest after bending freehand. Here again, it's a relatively simple affair, but I will talk more about the design as I build it. I figure, if you're building the molds, might as well build the clamping station at the same time and save some scrap.
In the meantime, I have a piece of redwood that I have been using for guitar tops. Since the parts have still not come in for my band saw, I have set up a time Tuesday to use the one at the school where I administer to re-saw some plates. The responsible dean found it all very amusing, the Provost in the wood shop, and wanted to be there with camera should I happen to cut off a finger. I can get a start on some sound-boards while slowly putting everything else together. I've made the jointing jig, and I will likely use the zip flex pearl from LMI for the rosette itself, along with some perfling material. I'll likely order all that after the holidays.
Sunday, December 11, 2011
Radius Dishes Continued
I have pretty much followed through on my plan for the radius dishes. I had enough scrap ply left from the shop cabinets to build the jig that I used to cut the plates. There are a couple of things that I should mention up front. It makes an unholy mess of MDF dust. Wear a respirator. If I were making these dishes for a living, I would have figured out some method of dust collection, but for the two-off that that I'm making, I assumed clean up would be easier than rigging some elaborate method of dust collection.
Pictured, you can see the Xmas Tree Stand that serves as the base, the two end pieces to the right, the two rails for the router on the left, and the two sides on the foreground. The 1/4 inch MDF attached to the one side is a template for the radius that will be cut into the side piece. I have a nice one inch pattern bit that cuts such things like a champ and the template was an excuse to use it. Since we're not talking a ton of material that has to be removed, you could join the two side pieces together, scribe the arch, then remove the material with a belt or bench sander. Either way, it would work, but I recommend the investment in the bit.
Pictured, you can see the dish blank mounted on the Xmas Tree Stand. It's a rather simple affair. Use a wooden dowel. I used a 1/4 inch dowel. Your router bit is going to hit it, and you don't want to waste a router bit on this project. To make the blank, I did as described. I cut the MDF to size into two 22 inches squares. I then used a very simple circle jig. In a scrap of 1/4 MDF, I cut a hole large enough to accept a brass bearing on my router. The measurement is to the outside edge of the bit -- in this case a 1/4 inch spiral upcut -- and I marked the location on the MDF for a 21 inch circle (10 and 1/2 inches from the edge of the bit). I drove a finish nail through the MDF at the radius mark into the center of the dish, and viola! A circle cutting jig. It's pictured in my previous post. I cut the circle in the MDF to a depth of about 1/4 inch, then used my jig saw to cut the majority of the scrap away. On the router table, I finished the edges of the blank using my pattern bit running the bearing against the circle cut with the router. Since MDF chips easily, I rounded over the bottom of the dish with a 1/4 round over bit.
Pictured, you can see the router channel assembled. It didn't work exactly as I had imagined. With classic engineering oversight, on the length of the box, I had taken into account the width of the of the router base in determining the long end of the box, and so cut it only 3 and 3/4 inches longer than the 11 inch radius. I didn't take into account the handles on my router base. Also, I profiled the radius only on the long end of the box to the center marker. In another well-duh! moment, I messed up the measurements on the first go round and didn't take into account the off-set of the long end. I cut the radius from the center line of the side, not the center-line of the Xmas Tree Stand. I disassembled, trimmed it off and started over, but you can easily see that you would want the center line over the center of the dish not the side and the 1/4 deflection (or 1/8th) should be at the edge of the dish not the end of the side.
Here you can see the whole set up put together and ready to rout. Again, it makes an unholy mess of MDF dust, so use a respirator or something to protect your lungs. On the router, I used a 3/4 inch straight bit. The router wants to throw and spin the dish for you, but I could easily hold the router, hold and control the dish, and slowly advance the router from the outside to the center while turning the dish. The rubber pads on the clamps helped with that. I lightly pushed them against the dish and that too helped against the tendency to spin. I had thought of taking the handles off the router to make it fit the channel better, but thought better of it, and was glad I didn't.
When the dish comes out of the jig, you'll want to sand down the ridge on the edge and take away the router marks. But it worked, and I now have two radius dishes, one for the back and the other for the soundboard. The stuff in the jar is a mixture of titebond glue and water at about 50/50 mix. It's mostly just glue from nearly empty glue bottles. I rinse out the bottles and save the remnants. For lack of a better term, I call it sizing and I use it to harden MDF for sanding and just generally. I'll also put a coat of poly on them.
Pictured, you can see the dish blank mounted on the Xmas Tree Stand. It's a rather simple affair. Use a wooden dowel. I used a 1/4 inch dowel. Your router bit is going to hit it, and you don't want to waste a router bit on this project. To make the blank, I did as described. I cut the MDF to size into two 22 inches squares. I then used a very simple circle jig. In a scrap of 1/4 MDF, I cut a hole large enough to accept a brass bearing on my router. The measurement is to the outside edge of the bit -- in this case a 1/4 inch spiral upcut -- and I marked the location on the MDF for a 21 inch circle (10 and 1/2 inches from the edge of the bit). I drove a finish nail through the MDF at the radius mark into the center of the dish, and viola! A circle cutting jig. It's pictured in my previous post. I cut the circle in the MDF to a depth of about 1/4 inch, then used my jig saw to cut the majority of the scrap away. On the router table, I finished the edges of the blank using my pattern bit running the bearing against the circle cut with the router. Since MDF chips easily, I rounded over the bottom of the dish with a 1/4 round over bit.
Pictured, you can see the router channel assembled. It didn't work exactly as I had imagined. With classic engineering oversight, on the length of the box, I had taken into account the width of the of the router base in determining the long end of the box, and so cut it only 3 and 3/4 inches longer than the 11 inch radius. I didn't take into account the handles on my router base. Also, I profiled the radius only on the long end of the box to the center marker. In another well-duh! moment, I messed up the measurements on the first go round and didn't take into account the off-set of the long end. I cut the radius from the center line of the side, not the center-line of the Xmas Tree Stand. I disassembled, trimmed it off and started over, but you can easily see that you would want the center line over the center of the dish not the side and the 1/4 deflection (or 1/8th) should be at the edge of the dish not the end of the side.
Sunday, December 4, 2011
Shop Cabinets & Radius Dish
I did dig through my available plates, and unfortunately I didn't have one that would allow me to get a start on an actual guitar -- mostly scraps saved for various purposes, but mostly because I couldn't bear to throw out exotics, no matter how badly stained by the flood water. So, I am still awaiting parts for my band saw. I'll be able to re-saw some redwood for a soundboard, and I will probably buy the back and sides from LMI.
In the meantime, I have decided to go ahead and build a couple more shop cabinets. I had gone to the Depot to get what I needed to make my radius dishes, but they had cabinet grade ply on sale for a little over twenty bucks, so I took the opportunity. I will have scraps sufficient to make the router jig, and I did buy the 3/4 MDF that will be the dishes. The shop cabinets are relatively simple affairs. They are basically plywood boxes, joined with a tongue and groove -- that is, I cut a 1/4 groove on the sides of the cabinet, and a tongue on the top and bottom ends to fit the groove. One will be used for my routers, and the other will be used for miscellaneous power tools.
As I was building the lattice jig, I did get a start on the jig to cut the radius dishes. The plan is this: I built what I am calling a Xmas Tree Stand, which is basically just a plywood X with each arm 22 inches long. The MDF dishes will spin on this base. The router jig will be similar to the one used to shape the drum for the thickness sander with a couple of exceptions. My router base happens to be 6 inches wide, so two end pieces will be cut at 6 inches wide by about 8 inches tall. The sides will about 6 inches wide as well (conservation of scrap) and about 25 inches long. One end of the jig will be attached to the Xmas Tree Stand and the other will overhang about three inches or the radius of my router plate.
I plan to profile the sides with the arch on one side for the back using my router and a flush cut bit. The first step is the creation of a template for the arch. I use my metal shop ruler to create the arch. I c-clamp a small block of scrap to the back-side of the rule, then clamp that down at the center of the arch. I then deflect the ends up to create the arch, scribe it, then sand to the line on 1/4 inch MDF. Remember, the low point of the arch should be over the center of the Xmas Tree Stand, and should allow enough clearance to attach the sides of the jig to the ends. To accommodate that, I measure in 3/4 inches from one end of the side (where it will attach to the fixed side) then 11 and 22 inches from that mark. The 11 inch mark is the center, and I deflect the rule up 1/4 inch on each of the other marks. I then double stick the template to the side, and cut with the pattern bit.
The amount of deflection at either end can be easily calculated (though I had to be reminded of high school geometry and algebra to do it). Take the radius of the dish (in my case, 11 inches) and square it (121 inches). Take the radius of the back and square it (in my case, 20' or 240 inches, squared is 57,600). Imagine a line tangent to circle 20' in diameter. Now, imagine a point 11 inches out on that line from the point where it intersects the circle. Using the Pythagorean theorem (a squared + b squared = c squared), you can calculate the distance between the point 11 inches out and the center of the circle (in my case the square root of (121 + 57,600) or the square root of 57,721, or 240.25195, which I rounded to 240.25). The difference between the radius of the back (or the distance to the point where the circle intersects the tangent) and the distance to the point 11 inches out on the tangent line is .25 or 1/4 inch. So each end needs to be deflected up 1/4 inch. For the soundboard, I'm going with 1/8th inch.
When I have the arches correct, I will attach a 7 and 1/2 inch wide strip of thin ply to the arch with screws. I'll clamp the ends to the sides so I can get the width exactly right, and then I will attach it to the Xmas Tree Stand so there is sufficient clearance for the MDF dish. Before I cut the dish, I will cut the slot in the 1/4 ply for the router bit, put the dish in place, and cut up and back to the center mark while spinning the dish slowly.
I finished the shop cabinets, but didn't get as far beyond that as I had imagined -- focus on one thing at a time. So the dishes are a project for next weekend. I will let you know how it really went.
In the meantime, I have decided to go ahead and build a couple more shop cabinets. I had gone to the Depot to get what I needed to make my radius dishes, but they had cabinet grade ply on sale for a little over twenty bucks, so I took the opportunity. I will have scraps sufficient to make the router jig, and I did buy the 3/4 MDF that will be the dishes. The shop cabinets are relatively simple affairs. They are basically plywood boxes, joined with a tongue and groove -- that is, I cut a 1/4 groove on the sides of the cabinet, and a tongue on the top and bottom ends to fit the groove. One will be used for my routers, and the other will be used for miscellaneous power tools.
As I was building the lattice jig, I did get a start on the jig to cut the radius dishes. The plan is this: I built what I am calling a Xmas Tree Stand, which is basically just a plywood X with each arm 22 inches long. The MDF dishes will spin on this base. The router jig will be similar to the one used to shape the drum for the thickness sander with a couple of exceptions. My router base happens to be 6 inches wide, so two end pieces will be cut at 6 inches wide by about 8 inches tall. The sides will about 6 inches wide as well (conservation of scrap) and about 25 inches long. One end of the jig will be attached to the Xmas Tree Stand and the other will overhang about three inches or the radius of my router plate.
I plan to profile the sides with the arch on one side for the back using my router and a flush cut bit. The first step is the creation of a template for the arch. I use my metal shop ruler to create the arch. I c-clamp a small block of scrap to the back-side of the rule, then clamp that down at the center of the arch. I then deflect the ends up to create the arch, scribe it, then sand to the line on 1/4 inch MDF. Remember, the low point of the arch should be over the center of the Xmas Tree Stand, and should allow enough clearance to attach the sides of the jig to the ends. To accommodate that, I measure in 3/4 inches from one end of the side (where it will attach to the fixed side) then 11 and 22 inches from that mark. The 11 inch mark is the center, and I deflect the rule up 1/4 inch on each of the other marks. I then double stick the template to the side, and cut with the pattern bit.
The amount of deflection at either end can be easily calculated (though I had to be reminded of high school geometry and algebra to do it). Take the radius of the dish (in my case, 11 inches) and square it (121 inches). Take the radius of the back and square it (in my case, 20' or 240 inches, squared is 57,600). Imagine a line tangent to circle 20' in diameter. Now, imagine a point 11 inches out on that line from the point where it intersects the circle. Using the Pythagorean theorem (a squared + b squared = c squared), you can calculate the distance between the point 11 inches out and the center of the circle (in my case the square root of (121 + 57,600) or the square root of 57,721, or 240.25195, which I rounded to 240.25). The difference between the radius of the back (or the distance to the point where the circle intersects the tangent) and the distance to the point 11 inches out on the tangent line is .25 or 1/4 inch. So each end needs to be deflected up 1/4 inch. For the soundboard, I'm going with 1/8th inch.
When I have the arches correct, I will attach a 7 and 1/2 inch wide strip of thin ply to the arch with screws. I'll clamp the ends to the sides so I can get the width exactly right, and then I will attach it to the Xmas Tree Stand so there is sufficient clearance for the MDF dish. Before I cut the dish, I will cut the slot in the 1/4 ply for the router bit, put the dish in place, and cut up and back to the center mark while spinning the dish slowly.
I finished the shop cabinets, but didn't get as far beyond that as I had imagined -- focus on one thing at a time. So the dishes are a project for next weekend. I will let you know how it really went.
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