Wow! Thanks for all the details.
Inexpensive Fretboard Miterbox
Ok, this is very close, for detail. First, the 7mm brass tubing is from when I turn pens/pencils. I found a drill bit that fit perfectly in the tubing and ground the point on the shaft of the drill bit and broke off part of the drill portion; leaving enough length to insert in the wooden knob I turned out of some scrap. The washer, glued to the knob, is only to give a firm seat when the pin is inserted in the tubing. I will attach the spring in the pic using a couple of small eye screws, one in the miterbox and one in the wood knob. The spring isn't really required but I had some misc. springs on hand. A little silicon spray makes for a very smooth slip fit of the pin in the tubing. The angle of the taper lets the pin fit about half was in the indexing holes.
Oh, the white board the box is mounted on is a piece of shelving from Lowes but you could use any truly flat plywood. Also, you will see, in other pics, two pieces of wood I have glued to the shelving to serve as 'steady rests' at each end of the miterbox.
Whew..... I think that covers it but I will be glad to answer any questions.
Now you see the aluminum angle with the indexing holes on the bottom attached to the board which 1/8" less in width than your fretboard. You also see the piece of channel I attached as a 'stop' to the end of that board with two screws. The 3rd screw is to temporarily hold your fretboard secure while sawing the fret kerfs. This fretboard is one I have made by laminating walnut on top of cherry. The screw hole in the fretboard will be hid later when you attach your tuner head to the fretboard.
Ah, the tricky part. To determine the location of the indexing holes, I used a commercial fretboard to transfer the spacing to the angle stock that is screwed to a 'simulated fretboard, 1/8" less in with, than the 1 1/2" fretboards I make. This all goes on the bottom miterbox and your fretboard goes on top. (should be more clear in a following picture)
A 6" machinist scale fit perfectly in the precut slot and allow me to use a try-square to transfer an accurate scribed line to the aluminum stock. Be sure you always measure from the same side of the scale all the down the fretboard. I did use red machinist dye on the aluminum stock for better visibility and it has obviously been wiped off now. Yes, there are charts giving specific measurements for the fret spacing, but that would have required a digital vernier caliper and I don't have one. :)
The diameter of the index holes was determined by the diameter of the indexing pin I had previously made (to come in another picture). I did, after drilling the holes, then slightly, very slightly, countersink each hole to make it easier for the indexing pin to center itself.
updated by @kusani: 04/23/17 09:23:13AM
The yellow strip of thin plastic, I made several, are spacers to raise the fretboard (if necessary) when using thiner fretboard stock to maintain the desired depth of slot. I do have a lot of sheet plastic of varying thicknesses to use; but cardboard, etc. would work as well. Note the thicker side of the angle is on the inside of the miterbox.
Photos 1 & 2.
Here is the info on the aluminum stock I used, with the exception of the small piece of channel which I believe is 3/4" x 1/2" (Will check later)
All screws most all screws are countersunk flush with the stock. The exception are the two screws on the upper right which are in slotted holes to allow for adjustment to keep the saw blade aligned. I did put two o-rings on the two black cams to more accurately secure the fretboard while cutting the slots. I run the o-rings up/down the cam so they are aligned center with the fretboard I am making.
Note: as you read through these steps, keep in mind the space in the bottom of the miterbox between the front of the box and the flat stock is needed to acommodate the narrow side of the indexing aluminum angle. It should be a 'slip fit'.
updated by @kusani: 04/22/17 06:58:02PM
Purchased a $12 miter box, Stanley, and some aluminum bar stock from Lowes and made a miter box for cutting fret slots as well as slots for nut and bridge. The 'indexer' was made from aluminum angle and is set for 26" VSL. The Yellow strips of plastic, on the far right end of the white base board, are 'spacer' strips, made from thin plastic sheet, for varying thickness of fretboard. The fret saw was from Stew/Mac. The aluminum angle on top of the miter box serves as my stop.
updated by @kusani: 04/20/17 08:58:59PM