Brian Posted November 19, 2002 Report Share Posted November 19, 2002 Ok so I already know that most luthiers in small shops use a pre-shaped block to sand down the radius when making a fret board....... Larger shops use a twin arm jig thats motorized and swings the fret board across the abrasive to radius the top........... But just how does one go about doing a compound radius, anybody have a clue? Quote Link to comment Share on other sites More sharing options...
DaveK Posted November 19, 2002 Report Share Posted November 19, 2002 Did you try the Stew Mac website ? Go to : Fretting supplies : Fretting tools : Fret Dressing, Leveling and Polishing : They have what they call "Wooden Radiused Fret/Fingerboard Leveling Blocks" They create an accurate playing surface radius, quickly and without guesswork. For compound radii, change blocks as you progress along the fingerboard. Hope this helps you Dave Quote Link to comment Share on other sites More sharing options...
Brian Posted November 19, 2002 Author Report Share Posted November 19, 2002 Thanks! I still wonder how they do it on a mass production level though........ Quote Link to comment Share on other sites More sharing options...
LGM Guitars Posted November 19, 2002 Report Share Posted November 19, 2002 elementary my dear watson, with CNC milling machines, you can create any compound radius you want, they simply use a (usually 1/8") straight bit and a 3D milling program. The bit cuts literally hundreds of passes, then all that is required when completed is a couple swipes with sandpaper and you're done, I had to do this in the metal shop on aluminum parts a few times. Any mass production shop has CNC equipment, and a compound radius board probably takes about 1 and a half minutes in a high speed machining center to produce, if you consider probably 1 minute part change, that equals 192 fretboard a day based on 8 hours, but I know most of those companies run shifts Really, it's not so hard to understand when you consider the back of every neck we have is a compound radius from nut to heel, and those are all done on CNC machines. Quote Link to comment Share on other sites More sharing options...
Jehle Posted November 19, 2002 Report Share Posted November 19, 2002 Excellent question and equally excellent answer. Thanks for the info guys. I'm in the soaking up every scrap of information that I can phase. Quote Link to comment Share on other sites More sharing options...
Dave M Posted December 12, 2002 Report Share Posted December 12, 2002 Actually, it's pretty easy for a small time builder to knock out a few compounds. I use the blocks, myself, but I have seen the twin arm jigs. Just make the arms two different lengths. Make it like a swing with one chain shorter than the other, then swing it back and forth over a huge belt sander. I would build the belt sander into a benchtop, and build the frame over the top of it. By angling the top bar, and altering the uprights, any compound radius could be done. we had a jig just like this that we used to make the curves for wooden boat rudders, except we had a few extra steps in, as there were three different coumpound radii cut on top of each other for each side of the rudder, or daggerboard. I have seen wooden frames, with adjustible arms that look fairly easy to make. I wish I had made a couple of fretboards when I was working on the boats, but I never got the chance. One other small safety tip. Always know where everything is, when you turn on a 42" belt sanding table. Especially if you have a 38" inseam, and are standing next to a 42" workstand, with workboots on, and there is a coffee cup sitting on the belt. I'll let you all guess where that thing hit me, and the worst guess is gonna be the right one :o Quote Link to comment Share on other sites More sharing options...
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