Official Luthiers Forum!

Which way do you cut your fingerboard radius? Do you cut with the grain or cross grain? What cutter shape and size do you use?
How much step over?

How do you hold them down:
- Clamps or jig/fixture,
- Vacuum
- Tape

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tim...
http://www.mcknightguitars.com

I have been doing mine running with the grain, using a 1/2" ball end mill with a .125 stepover per pass. I havent got around to cutting the slots yet, but the radiusing part seems to work nicely. I use double sided tape to hold it down, but I can see the advantages of going to a vacuum system.

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Reguards,

Ken H

..double sided tape and I run with the grain. You almost always want to run with the grain, on any cut. Cutting cross grain is always more prone to tear out & such.

I use a 1/2" ball mill at about a .050 or .075 stepover

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http://www.PeakeGuitars.com

Hi Tim, I just cut my first fingerboard on the machine yesterday. I cut it with a 1/4" spiral carbide downcut across the grain finishing with a 20% step over. it worked great although it will require a quick sanding. I generally do that after the neck is on the guitar right before installing the frets. There are some but marks on the board but not much and no tearout at all, just a quick sanding will do nicely, much better than my old method running with the grain. Of course my old jig was getting a little loose in accuracy.

I used double sided tape this time but I am about to make a vacuum jig with indexing pins.

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Tickle your guitar daily, and it'll tickle you back.

1" carbide ball, vacuum hold down, small stepover (under 0.05")

Going perpendicular to the grain is a lot of short moves and it hard on your machine and much slower than going lengthwise. You should also be running the lengthwise passes parallel to your lightest axis, especially on a router where there are a lot more deflection issues.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I've only tried it once and found that the setup for milling with fretboard on the neck too too long for the end result. I go through a lot of edge sander belts though, so I wouldn't mind having a milling process prior to sanding to do the major work.


Bob, Parser, is your cutting strategy parallel passes, tapered to match the fingerboard, back and forth or up and over to always be climbcutting etc?

I carve a rectangular surface which overlaps all the edges at least a bit and come back and profile cut the board later. I use parallel passes which remain at a consistent Z height. I use mixed cutting - conventional and climb - with passes this small, it doesn't really matter too much...

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http://www.PeakeGuitars.com

Parallel passes, parallel to the grain. Parallel finishing passes are easiest on your machine and more accurate at speed.

Parser's correct in that the climb cuts will cover up the conventional cuts on a strictly convex shape like a FB.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Conical passes for the "compound radius".
And each fret slot depth to match.