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Shane, here's what I do.

This contraption first gets bolted to the table. Notice the aluminum rails that almost touch the belt. The radius guides track against those. The two levels of slots just give you two different areas of the belt to work on.



The fingerboard mounts here with double stick tape. You can make different guides for different radii. Cylindrical or compound works. I made them depth adjustable. The locking bolts on each end slide into the slots on the fence to support the work and keep it parallel to the table while allowing it to pivot. After the depth is adjusted, just sand and pivot until the guides touch the rails.



I also added a micro adjust on the fence. A nice feature.




Here's the whole thing (before I added the micro-adjust) Hope this helps.

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http://www.chassonguitars.com

Hi Rob,

Yes, that's another adjustment I have made. The bit protrudes approx. 1/4" below the radius so it does create an 11 3/4" radius. I have found that the sanding process takes care of that pretty quickly.

Martin

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Martin Taylor
http://martintaylorguitars.com.au

This is a little pedantic, but here goes anyway:

Martin, your jig clearly works well, and is producing nicely curved boards, but they're not truly radiused, straight off the jig. I don't know what the curve is (not that it actually matters) but to get a true radius you need a shipwright's compass (long compass in some parts of the world) arrangement. So instead of the bottom of the router carriage being curved, it comprises two straight lines, apex of the "triangle" at the bit position. That arrangement, with the straight bearing surfaces, definitely produces circular arcs, so, by default, a curved bearing surface must produce some other curve.

The difference between a circular arc and what you have will be quite small and if you're finishing up using radiused sanding blocks you'll end up with a true radius anyway. If you invert the curvature (or straights) on the base of the router jig you can make your own "radius" sanding blocks.

Anyone making one of these jigs (I have a similar one that does compound radius fretboards) can make the construction easier (and have true radii) by using straights instead of a curve on the base. For those in doubt, Google shipwright's compass or long compass for the geometry (also in the book).

As I said, not that it matters, but just so you know...

There's an interesting discussion on the forum here about compound radius boards and how I and others go about making them.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I found this ingenious fretboard radiusing jig on YouTube. Seems very easy to make standard radius and compound radius fretboards by simply changing the ends. I also like that you aren't wielding a router around, instead, here you use the router table. I've made this jig, but I haven't radiused a fretboard with it yet - I've been so busy on other parts of the 3 guitars I'm currently building. Hope this gives you another idea

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Rob Flindall
Flindall Guitars
http://www.flindallguitars.com
https://www.facebook.com/FlindallGuitars

Thanks for the confirmation Anthony and Todd, just wanted to make sure I was thinking correctly, that for the Martin Taylor jig the radius on the jig has to be increased by the bit protrusion, vs the 12" radius noted on the plan.
Agreed Todd, will draw a full scale to get it just right.

Rob

dang, that guy takes his PPE seriously

Kent, that is a great jig! I have the same edge sander and will be making your jig for sure. I also really dig the neck shaft jig on your site. I like simplicity.

Sent from my DROID RAZR using Tapatalk 2

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jw ( o)===:::

I have a jig that I made a few years ago that is very similar to the one from Luthier Suppliers for the thickness sander. It works very well for me, but it`s dedicated to only one setup (16" to 25").
I figured that someone would come up with a better version of what I started with, and by golly, it happened.
No need to fear it, and if you study it a bit, you`ll understand how the principle works and should be able to change the radii at each end to suit your needs.
Also, light passes aid in getting it near perfect before a light hand sanding (or even scraping), inlays included, providing you inlay deep enough.

Coe Franklin

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Give me 50 cents worth of regular.
Check my oil too, if you don`t mind,,,

That is awesome! I am working on a pho powered cyborg radius cutter. Has anyone tried using a 1/2" down cut spiral bit?

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Pat

i have the Luthier Cool Tools plan and just haven't gotten around to building it. I do like that jig you posted from luthiers supply. Seems actually easier then the other jig....Mike

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Another day, another dollar.

Martin, I got around to building a radius jig using your excellent plans.
Thanks again for posting.
It worked much better than I anticipated!
I first tried a Lee Valley 1/2" shank Core Box Bit as recommended in this thread - it did not work for me - left lots of valleys....yuccch!
Tried with a 1/2" shank 5/8" flat -bottomed bit and it worked like a charm!
A quick touch-up with 220 with the radius block and it came out perfectly!
I wonder how Fillipo made out with his version of 'the McClary Fretboard Jig'?

I use a vertical sanding belt with a concave backing plate, cut to a compound radius. I radius after finish and after the neck is glued on. Takes about 30 seconds or so per guitar. Basically press the fingerboard into the belt and sand till it meets the backing plate and voila!

30 seconds?
After the neck is glued on?
Radical.
Got a picture?

Hmmm...

PM me your email, I've never been able to upload pics here without a ten step two computer process...

First time I've been back here in quite a while. Did you make a version of the radius jig Filippo?

Thanks for the endorsement. I designed and posted it on MIMF, Todd Stock revisited it and made a couple changes and posted here at OLF...just for the record. The PVC version was by Scatter Lee on TDPRI.