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I have made 6 guitars, all of which I used pre-slotted, pre-radiused fretboards. Now I want to make my own fretboard. I have this very nice ziricote blank I got from RC Tonewoods, that will look real nice on the black limba I'm using. I started with a IRW blank for practice. I had no trouble thicknessing the board with a wagner safety plane and I cut the slots with a Stew-Mac slotting jig. Now here's where the trouble starts... radiusing the board. At first I tried using a 18" aluminum radius block, but that was wearing me out. So I tried to use my LN low angle block plane to take some stock off with some success... Now I'm working on making a jig to use the safety plane...

What method do you use to put a radius on the fretboard? What are some methods to successfully do this?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I rough it in on the belt sander and finish it up with the 18 inch long radius beam, then check it with radius gauges. Takes about 5 minutes.

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Old growth, shmold growth!

Steve, there's also a rig (I think it was Sylvan Wells who posted it) where you start with a strip of ply or MDF a little wider and longer than the fingerboard and attach a 3/16" or so cleat to one of the underside edges to give it a tilt...then attach some sandpaper along the length of the top side for non-slip purposes...place fingerboard on rig and run thru sander (I forgot to mention you need a sander!)...turn fingerboard around for next pass...then all you have is clean up with the radius block...

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http://www.presnallguitars.com

Early on, I heard a tip from someone about making a radiused sanding beam. Take a straight, flat, stable 4x4 & glue down two 1/4" dowels, parallel, about 3" apart. Make a 12" rad. (or whatever) scraper. Fill between the dowels with "Bondo" and immediately drag the scraper down the dowels, shaping the "bed" to a consistant 12" radius. When dry, glue sandpaper. I've radiused most fingerboards with mine, including block-inlaid.

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Dave
Milton, ON

I've radiused fingerboards several ways over the years including a swing jig on a belt sander, a radius jig on belt sander as well as CNC.
I've found that what works best for me is roughing out the radius manually on a belt sander checking several times with a radius gauge.
Then finish with the 18" aluminum mentioned above using a guide to keep it running parallel with the fingerboard.
I do all the above with the fretboard mounted on the neck but it could be done prior to mounting by "tacking" the fretboard to a holder of some sort.
"Tacking" can take the form of double sided tape or a few spots of medium CA.
Nelson

I start off using a bench plane and then I use the maple blocks that Stew Mac sells followed by the sanding beam to get a conical final shape. I think they are a good bang for the buck, at a price point that rivals a DIY job.

I've used Todds jig ever since he posted it on the MIMF a few years ago. Works great. Use a box core bit with a 1/2" shaft to pretty much eliminate chip out and do climb cuts.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

+ another 1 for Todd's plan!

On further inspection, I realized that I was able to leave out the metal runners. Works great that way, too.

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A world without music would Bb.

Nice isometric hand rendering, Todd. You're a man after my own heart. Great work as usual!

+10 for the jig!!!!! works great!!!!

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MK5acoustics.com

Can't do a compound type radius with that jig though.

Here's the one I use. It allows for different radii at each end of the board as you can see in the first picture, the pivot points are different which allocates the different radii at each end. Don't have any plans for it so you'll have to figure it out (easy if you can build a guitar...)

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do you rout in two stages?????

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MK5acoustics.com

This is the way I've done all four instruments I've built. Doesn't take very long, if you use good sandpaper. I use 60 grit 3M Sandblaster paper, available at my local Lowes. It cuts pretty fast, and doesn't load up. If it starts to, a quick swipe on my pants leg cleans it right up.
If a jig or template is necessary, i'll build it. But I'd rather spend my time building guitars, not jigs and templates. That may change as i get more experience, but I seriously doubt it with regards to radiusing a fretboard.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.

that routing jig is easy as pie to make... I wouldn't be intimidated by it for sure, and it works well to get the initial radius, which can be fine tuned with a radiused sanding block, straight edge, and curved card scraper (I made one). Good luck.

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

I do compound radius fb on my jointer bed. I made a jig that has a beam between two semi-circular wheels. The neck in my case gets screwed to the beam and the wheels ride on the infeed and outfeed beds. Pass, pass, pass As I rotate the jig by hand until it is done. New radiuses can be made easily. You can't radius a fingerboard that has slots though.

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Ken

For my current project, I wanted to try a compound radius. I thought long and hard about how I wanted to tackle this, then threw it all out the window and did it my hand. I carpet taped the slotted and tapered board to a marble slab and used a plane. I followed the taper and tried to take full strokes along the string paths. I was surprised how QUICK AND EASY it was. I didn't bother to measure the radii but they feel about right and a straight edge shows the board is straight along each string path. The board is fretted and attached to the neck (90% carved) but I am not near ready to put the whole guitar together, so I may run into unforeseen setup problems, But I don't think so.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I could see the router jig once set up being useful to knock off like 50 boards at a time or something. Otherwise I agree with Fillipo, with 60 grit paper you can rough a board out in no time.

Well, I did the first 8 guitars with a sanding block. It sucks!!!! 60 grit to hog, 80/100 grit to remove 60 grit sanding marks, 150,180,220,320. The first few grits are going to need a fair amount of human power sanding back and forth, back and forth.....with the remaining needing about 30-40% as much sanding. So after the initial hogging off of material (and during) one needs to stop, brush off the sandpaper of dust, vacuum up the dust off the board and continue, then after one grit is done, you need to load the sanding block with fresh paper of the next higher grit. If stick on sandpaper is used, this is pretty quick but still needs to remove the first grit, clean off the block of any possible glue residue and stick on the next grit etc... everything takes time.

The other factor with sanding in the radius is that it's easy to get the board thinner on one side versus the other (bass to treble side) so a decent sanding jig needs to be made to ensure the sanding block is held parallel to the surface holding the fretboard.

With my jig, I only need to set my router hight which takes about 1 minute (or less) then I'm routing. I can go right to 220 grit backed by my hand after routing... Once my board is thicknessed, tapered, slotted and bound, it only takes me about 3-5 mins to get the jig down, tape the board in place (vacuum would be quicker), set the router bit height and route (4-5 passes is all it takes). So for me at least, this is much easier and quicker and I like it

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Here is a link to Dave Fifield's compound radius jig, which is simalar to Rod's. http://www.cambrianguitars.com/compradjig.html

Bob

Here is a different take of Rod's and Dave's jig.

Chuck

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Get a couple of radius gauges to check with, just in case you ever decide to build a guitar with a Floyd Rose bridge.
For a Floyd Rose bridge you want a 10 radius at the nut and a 16 radius at the 22nd fret. If you have an adjustable bridge it doesn't really matter as long as the saddles are individually height adjustable.

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Old growth, shmold growth!

The approach I've used is to hog off the main waste with a large, sharp plane, then test my accuracy with a Stewmac (or LMI, can't remember) radiused sanding block. With a little practice I can get relatively close to a decent radius. Then I use a straight and true sanding block (I',m using a 10" plane bed with adhesive sandpaper on the bottom at present) if I want to approximate a compound radius.

I don't much like creating fine ebony sawdust - it seems to crawl up my nose whether I'm wearing a mask or not. So I try to get close with the plane. I haven't tried to create a radius jig for the router, but I'm not particularly gifted at building precise jigs. For me it's a bit of a chore that I'd rather use the brainpower for the guitar building. It's taken me some time to say "uncle" but that's how it is for me.

Hmmmm interesting... Ok I want one now But still... I think maybe Fillipo and I ought to be on one team, and you can pick your teammate. The race is on

As for the asymmetric sanding using a block... I will attest that this is true. It happened to me on my very first build using a sanding block. But then I figured out that to prevent that you just count your strokes, do 25 in this direction then flip it and do 25 in the other. Works like a charm.

Everything has pros and cons.

Sanding it in allows you to correct as you go if necessary, though with a little practice that shouldn't be a problem.

Routing the radius requires you to have the jig set perfectly also so that one side doesn't end up thinner than the other, and if t's a little off, it's too late once you start, and also the ends as well, and the platform the fretboard rests on must be perfectly flat, the fretboard must also be attached perfectly parallel to the router path.

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Old growth, shmold growth!

I wanted to run a somewhat nutty idea by y'all on this one.

I make compound radius fretboards on my CNC machine and while the surface comes out really nice with a .008 step over and a 1/2" ball nose bit, it still needs sanding to get it perfect.

The idea I had was to make a semi circular cylindrical sanding block that has the nut radius machined into it at one end, the FB end radius at the other and a smooth transition between the two machined between the two ends.

To use it, you'd rotate 90 degrees in one stroke it as you sand down the fretboard. (In the photo below, I used a 4 and 8" radius just so it would be easier to see but obviously, the actual start and end radius of the board would be machined in an actual sanding block). If 90 degrees is too much, the same thing could be accomplished in say 70 degrees or something like that. The key would be to try and match the radius of the board to the radius of the block as you're taking strokes.

I realize it wouldn't be perfect and would take some technique to use but, as luthiers we're used to technique oriented stuff.

What do you guys think? Would this help sand a compound radius board or do you think it would be too difficult to get aligned with each stroke?

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