#1 resource for Cigar Box Guitars, Free Plans, How-To, Parts & More!

What's the easiest way to radius a fretboard?

I've searched through the past discussions and haven't come across the answer - my apologies if I've missed it.

Anyhow, I'm looking to build a 6-string CBG and so would like to radius the fretboard. Not a compound radius, just a simple one like on most acoustic guitars.

I've got a safety-planer, and so can theoretically use that to do some approximate shaping. And I've got a handplane that I'm not very good with that I could do the same thing with. But I'm assuming that to finish this I need to create a sanding block with a radius curve on the inside. Which of course, becomes a chicken & egg problem.

So, what's the easiest way to construct this? I was thinking that I could create the block out of a set of 2x pieces that I cut the radius out with on my band saw (which will be very primitive). Then find some large cylinder of the appropriate radius, put sandpaper on that, and then use that to finish the sanding block radius. So, any suggestions on a simpler method? (and I'm not above buying a tool - just don't want to spend $80).

Thanks in advance,

Ken

1 member likes this

▶ Reply to This

Replies to This Discussion

Permalink Reply by Wes "I'm Baaaaack" Yates on October 10, 2010 at 12:29pm

Lucky for you I just created a post [an on the cheap tool solution] for this. Check it out here.

-WY

▶ Reply

Permalink Reply by Bear on October 10, 2010 at 1:19pm

Since you have a Safe-T-Planer, here's something I found online that looks interesting:

▶ Reply

Permalink Reply by ken farmer on October 10, 2010 at 2:04pm

Wes & Bear - I don't see the links that either of you are referring to in your message...

but I did track down the Wes links - and you're right - that's exactly the kind of idea I was looking for:
http://www.cigarboxnation.com/group/secretsofthecbgunderground/foru...
And it's perfectly elegant. I'll try that out tomorrow night. Damn, but the internet is cool. And this site especially so.

Ken

▶ Reply

Permalink Reply by Outhouse Instruments on October 10, 2010 at 2:29pm

Wes' idea is a good one if you're only gonna do one.
A quick easy way .... the way I plan to do one someday ....
1- add a temporary extension table on my bandsaw.
2- figure out the radius I need and put a nail at what would be correct pivot point on the extension.
---OK, what's the correct point? 12" for a12* radius, 7" for a 7* radius .... see where this is going?
( disclaimer - research. I came across these figures on the 'net. so research a bit to make sure it's right)
3- I'll use 1/2" thick stock ( plywood?) 3" wide 2 ft' long. starting at 13" , I'll mark and drillholes 1" apart all the way to one end.
4-Put the 13" hole on the nail and swing it thru the the band saw, carefully cutting a clean arc. Do this until you run out of holes.
----- Now you should have a bunch of 1"x1/2" wood blocks with a concave radius on one side.
5- stack'em up even with the curved side together, glue them together and sand just enuff to clean up, or add a piece of then wood or masonite to the arc ... spray glue the paper on and dere ya go!

Matt

Any one want to add to or correct this info .... PLEASE DO SO!

▶ Reply

Permalink Reply by Bear on October 10, 2010 at 2:31pm

Wes' link is the word "here" in red (Wes, how'd you do that?).

I googled "make a radius block" and found a page on Project Guitar Forum that looked easy using a Safe-T-Planer. Don't know why my link didn't show up.

▶ Reply

Permalink Reply by Wes "I'm Baaaaack" Yates on October 10, 2010 at 2:39pm

the little button in the comment/reply that looks like a chain. highlight the word(s) you want to make a link then click that and add in the URL.

-WY

Bear said:

Wes' link is the word "here" in red (Wes, how'd you do that?).

I googled "make a radius block" and found a page on Project Guitar Forum that looked easy using a Safe-T-Planer. Don't know why my link didn't show up.

▶ Reply

Permalink Reply by Wes "I'm Baaaaack" Yates on October 10, 2010 at 2:47pm

This actually looks promising <---(link is the word 'This')

-WY

▶ Reply

Permalink Reply by Wes "I'm Baaaaack" Yates on October 10, 2010 at 2:53pm

Here's your stack technique but using a router instead of a band saw.

http://www.mylespaul.com/forums/luthiers-corner/80744-diy-radius-sa...

-WY

Matt Towe said:

Wes' idea is a good one if you're only gonna do one.
A quick easy way .... the way I plan to do one someday ....
1- add a temporary extension table on my bandsaw.
2- figure out the radius I need and put a nail at what would be correct pivot point on the extension.
---OK, what's the correct point? 12" for a12* radius, 7" for a 7* radius .... see where this is going?
( disclaimer - research. I came across these figures on the 'net. so research a bit to make sure it's right)
3- I'll use 1/2" thick stock ( plywood?) 3" wide 2 ft' long. starting at 13" , I'll mark and drillholes 1" apart all the way to one end.
4-Put the 13" hole on the nail and swing it thru the the band saw, carefully cutting a clean arc. Do this until you run out of holes.
----- Now you should have a bunch of 1"x1/2" wood blocks with a concave radius on one side.
5- stack'em up even with the curved side together, glue them together and sand just enuff to clean up, or add a piece of then wood or masonite to the arc ... spray glue the paper on and dere ya go!

Matt

Any one want to add to or correct this info .... PLEASE DO SO!

▶ Reply

Permalink Reply by Joe Minter on October 10, 2010 at 2:57pm

I just got some off ebay at a good price

▶ Reply

Permalink Reply by Bear on October 10, 2010 at 3:38pm

Looks like there are many ways to skin this cat! Here's the link to the Safe-T-Planer method I couldn't get to work before (thanks, Wes!): Click HERE.

▶ Reply

Permalink Reply by ken farmer on October 10, 2010 at 3:42pm

Thanks Matt. My band saw is too squirrely for that method. Maybe if I got a wider blade for it (or a better bandsaw).

Matt Towe said:

Wes' idea is a good one if you're only gonna do one.
A quick easy way .... the way I plan to do one someday ....
1- add a temporary extension table on my bandsaw.
2- figure out the radius I need and put a nail at what would be correct pivot point on the extension.
---OK, what's the correct point? 12" for a12* radius, 7" for a 7* radius .... see where this is going?
( disclaimer - research. I came across these figures on the 'net. so research a bit to make sure it's right)
3- I'll use 1/2" thick stock ( plywood?) 3" wide 2 ft' long. starting at 13" , I'll mark and drillholes 1" apart all the way to one end.
4-Put the 13" hole on the nail and swing it thru the the band saw, carefully cutting a clean arc. Do this until you run out of holes.
----- Now you should have a bunch of 1"x1/2" wood blocks with a concave radius on one side.
5- stack'em up even with the curved side together, glue them together and sand just enuff to clean up, or add a piece of then wood or masonite to the arc ... spray glue the paper on and dere ya go!

Matt

Any one want to add to or correct this info .... PLEASE DO SO!

▶ Reply

Permalink Reply by Outhouse Instruments on October 10, 2010 at 9:36pm

ken farmer said:

Thanks Matt. My band saw is too squirrely for that method. Maybe if I got a wider blade for it (or a better bandsaw).
,I think it would be worth trying on some scrap. Set the guides as low as possible ...... the blade couldn't get too squirrely on 1/2 stock.

I may try one tomorrow just for giggles. Of course I'll document the whole fiasco for your viewing pleasure

Matt