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Thanks for taking the time to do this Todd. Somewhere on another computer, I drew all the parts in CAD for an addendem to that first thread you did and then like many things, never finished it up. I should dig those up and finish them.
Marty

Can anyone think of a way to make a router jig for a non-radius shape more like a parabola as shown.

I can't visualize the router base/sled. A matching radius won't work because as it rotates they change in relationship to each other. A base with two rods won't work either becuase the distance will not be constant as it rides over the steeper part, compared to the ends.

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Ken

Thank you very much for sharing, I look forward to learning here at OLF

Thanks to Todd and Marty for this jig design. I'm about 75% of the way through building mine, with a few variations on the design, just to make it my own in some way, I guess. For one thing, I made the base 36" long so I can handle a 35" scale base fingerboard easily, and I've made two carriage assemblies so far - 7.25" and 14" radius so far.

One problem I had: the base of my router is 6" diameter, and I didn't check this until I had cut all the pieces for the router sled, but before I glued it up. So I devised a solution, and it worked out well. I'll post some pictures later today.

Thanks again!

--Steve

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---Steve

I have completed the radiusing jig, and tested it on a scrap fingerboard to make sure it works. I've made two sleds for it so far - one for 14" radius, and one for 7.25" radius. Thanks again for the design, guys!

Here are the pictures I promised yesterday. First, the router mounted in the 14-inch radius sled:


Next, the bottom half of the 14-inch radius sled on the track:


A detail shot of the end of the track:


Underside of the router carriage part of the 14-inch radius, showing how I made the carriage big enough to handle the 6-inch diameter base of my router:

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---Steve

Here's the first fingerboard to come off the jig:

It works GREAT! Still a lot lot of hand-sanding to do, but the hard work of sanding the fingerboard from flat to radiused with a sanding block is gone. What a great time-saver this thing is!

I've also completed the sleds for 9.5" and 7.25" radius. Next I'll make one for 16"

Thanks again, Todd & Marty!

--Steve

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---Steve

I probably over-stated the amount of sanding I had to do. What you describe was all it took for me too, after I had filled the small gaps in the edges of the inlays. It took a few minutes of light work, compared to one of two approaches I used previously:

1) Make some passes over the belt sander to rough in the radius, then use the radius block with 60-grit sandpaper to get the board as uniform as possible. When the radius is consistent and the fretboard true from end to end, move to 100, 150, 220, 320, 400, and 600. Ended up with a couple of fingerboards that weren't true doing it this way.

2) Start with 60-grit paper with the radius block on the flat fingerboard blank. Takes a long time, even longer with shorter-radius boards. Very time-consuming and a lot of physical labor. 100% success rate, but too much work for my taste.

I think the overall effort was 15% to 20% of what it was using the old methods. And the amount of sweat expended maybe 5%

--Steve

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---Steve

Can I offer an alternate method of doing fret boards?

Shop Fox makes a planner molder which can be had for around $500. It works great for a variety of projects including planning molding etc. it can also be used to make radius moldings fixtures and other. This is a nice machine for any shop that wants to do thier own planning etc. This machine is similiar to the William Hussey molder that has been around for many years. I would think that the Woodmaster planner/sander/molder could also be used for the same setup.

All this said buy knife stock or have custom knives made for your desired radius (cost $25-$150). The only catch that I have found is that for fret boards already sized you have to build a sled for carrying the fret board with a pocket the size of the fret board and extend the sled 5-6 inches beyond either side to advoid snipe. You can run 1 or 1000 and it is only a matter of feeding the machine and there is virtually know sanding if run at the proper feed and speed. If you cut the knife profile wide enough you can plane/mold 8" to 1" in width fret boards.

If you can't afford the machine in most area's there should be woodworking clubs where there should be a wood worker who has such a machine and who would be glad to run your fret boards if you owned the knives.

Kevin Waldron