JC's Lutherie Jigs
Jigs make work faster and/or more accurate. Today there are companies out there eager to sell jigs and fixtures to luthiers. Their products are very pretty, usually expensive, and from the reviews I've read, they perform well. I've not tried many of them. When I was coming up there were almost no commercial jigs or fixtures available and I guess I've stayed old school (or maybe just stubborn). I don't like to buy what I can make for myself, perhaps because I don't often know what I need until I need it, and then I don't want to wait around to have it. My jigs are seldom pretty, are usually cheap or free because I make them out of scrap wood, and may be improved, replaced, or abandoned as time progresses. This page isn't about demonstrating how clever I am but about throwing ideas at you that might make your work better, faster, or more enjoyable. If you think up any improvements on them please let me know.
I've published many of these jigs in American Lutherie magazine, especially the series I did about Charles Fox's American School of Lutherie. Charles really is an amazingly clever man, and many of the jigs he showed me he's no doubt left in the dust as new ideas occurred to him. I'm also going to include some jigs developed by the crew at Huss & Dalton (where I put in my 40 hours a week). It's going to take a while to build this page, so check back as you can.
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Witness the amazing Robo-Sander, invented by Texan Ken Picou. This is the 3" version, and it's nothing more than a sanding drum with a plastic bearing mounted on the bottom. It works just like a flush-trim router bit. Its slower than a router and not quite as accurate, but it has a 3" depth and is much less destructive to your work than a router bit might be. Grain orientation is unimportant. The smaller your shop, the more you need a Robo-sander, assuming you at least have a drill press. Even those $100 drill presses from the building supply stores work just fine. There's a large nut on the bottom of the Robo-sander for which clearance must be provided on your drill press table. Like this:
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On the left is a temporary rig. The drill press on the right has an auxiliary table permanently mounted for Robo-sanding. For normal drilling operations a board is placed over the drum relief hole.
Brace-shaping jig
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Top picture shows a pair of brace jigs, one for tops (with 25' radius) and one for backs (with 15' radius). Bottom picture is the back brace jig at work. Sanding dust tends to build up on the working surface of the jig and must be cleared from time to time or it affects the shape of the part. The threaded rod is super glued into the MDF form. The clamp is a short length of 1/8"x1" steel flat stock, usually available in 3' lengths at hardware stores.
Neck Profiling Jig
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This jig sets the final dimensions of the neck profile, including peg head thickness (not including the peg head overlay). Its held in place by spring clamps which are moved around to clear the work area as needed. The Robo-sander isn't a perfect tool, so multiple passes are usually necessary to reach the final shape. Label your jigs prominently---if you let them sit idle for long enough you may forget what they are for.
Neck Jig #2
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This is the partner jig to the previous one. It's simply the shape of the fingerboard you are going to put on the neck, in this case a 5-string banjo fretboard. The jig is fixed to the neck with double-sided tape, the unit is flipped upside down, then Robo-sanding begins. Avoid the peg head area. The heel is taller than the Rob-sander, so the table must be lowered and another pass made it finish it. The Robo-sander can't reach into the curved spot where the 5th-string tuner fits. Hidden behind the neck/jig is a 3/4" sanding drum that was used to finish this area. Since it has no bearing, care must be used to shape the neck without reshaping the jig. The jig could also be removed for this step, though I find that I can feel when the small sanding drum hits the jig and the work is finished. Making this jig out of hardwood rather than pine would add to its longevity, but its in the nature of some jigs to be used up as time goes on. Simply replace them before they become useless for the job at hand. Simple jigs like this one can be quickly reproduced using a router table and a flush-trim bit. Keep the original as the master and the copy as the work piece.
Table saw jigs can be idiot-simple or bizarrely complicated monsters. I like them simple, else I'm likely to forget how to use them. A good table saw is a genuine joy to use, but even a genuine piece of junk like my old Sears is miles ahead of not having a table saw at all. Setting it up requires patience, but good jigs do all the setup for you. Just about any jig you make up will be blade-specific. That is, changing blades will change the dimensions of your parts. If you're smarter than me you'll buy two identical blades so that when one is sent out to be sharpened you can still work with the other.
For most table saw jigs you'll need runners that fit tightly (but without binding) in the table miter slots. Like this:
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I make runner stock a bunch at a time from whatever MDF or plywood is on hand at the moment. Note that the runners in front fit the slot in my belt sander table. They don't interchange. I label them all just so later I don't throw them out as useless cut-offs. Let's start with a handy jig that's really easy to make.
The Long Ripper
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Just glue a runner to the bottom of a long, wide sheet and run it through the saw. Now anything you mount on the edge of the sheet will be precisely cut to that dimension, in this case the taper is being cut on a guitar fingerboard. Tee nuts are set into the bottom of the sheet, the posts are cut from 3/8" all-thread stock, and the clamps are cut from 1/8"x1" steel stock and bent slightly by smacking them with a hammer while they were mounted in a vise. The knobs are from Woodworkers Supply, but you could easily make your own by gluing the appropriate nut in a shaped piece of wood. Extra tee nuts will let you mount the posts in different places for different cuts, and you may find that more than two posts are nice to have. Once clamped up the work can be nudged if necessary with a tap from a softer piece of wood.
This jig does lots of things. For instance, say you want to make binding from the junk left over from a set of guitar sides but, damn, you forgot to joint the edge before you cut it off. Try this:
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The junk (koa) is clamped to the edge of the jig using a support stick, and a trip through the saw leaves a nice, straight edge. Now you can resaw the junk like this:
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A plywood insert was made for the saw, a Stew-Mac fret slotting blade was run up through the insert, and the fence was snugged up 1/4" from the blade. You could also overhang the junk on the edge of the Long Ripper to make the 1/4" cuts but using the fence is a little more satisfactory.
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The Wedge Cutter
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This is another way to use up junk wood, assuming you have any junk that matches (or contrasts!) with your binding scheme. Joint one edge of the stock (I like to use the belt sander), mount it in the jig, hold it down with the "lid", and saw out a nice wedge. The little table in the middle of the jig positions the lid securely. This is an H&D jig. There's a companion jig for routing the body for the end graft that I'll put in Other Jigs when I get to it.
The Nut Slot Jig
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Initially I made this jig to rout finished guitars for Floyd Rose locking nuts, but it does a lot more than that. Here I'm cleaning up the slot on a Weissenborn-style lap steel. Make the entire jig but leave the router table overly deep. Then, using your chosen bit, run the router across the table. Now the edge of the table is precisely where the front of your cut will be, making setup a snap. Tape the entry and exit of the cut to limit/prevent chipping.
