Friday, February 24, 2012

A Cool Way To Radius A Fretboard

I love building electric guitars, but the one task I never look forward to is generating the fretboard's radius. Like most small builders, I have always relied on radius sanding blocks to help do the work. The problem is, it takes at least an hour of vigorous work to get the job done. And that's for just one fretboard. If I have a stack to do, I'm in big trouble. My shoulders just can't take the work.

Over the years, I have tried a variety of jigs to help generate the radius, but none of them seemed to work very well. But then, after watching the movie "The Pit and the Pendulum," I hit upon an idea; What if I flipped the pendulum, attached the fretboard to the swinging end and ran my router along the centerline? I know that doesn't make any sense, but here are some photos of what I came up with:

The router slides along the top rails while the fretboard swivels on an arch from side to side. There are pins on each end, which can be positioned in different holes in order to change the radius to whatever I need for a given build. Best of all, I can even generate a compound radius! I can do a consistent radius from 7.5" all the way to 24" and everything in-between. If I place the pin on the nut end at 10" and the pin at the heel end at 16", I can get a compound radius. It really works and the results, so far after testing a couple of fretboards, is extremely smooth with only a 1/2" straight cut bit.

It only took me about two hours to make this jig. I used two sheets of 2'X4'X3/4" plywood, some woods screws, a couple of 1/4" screws for pins and a pair of skateboard bearings to help the router mount slide smoothly. If there's enough interest I'll post the plans for the jig. In the next day or so, I might upload a video of how it works as well.

8 comments:

  1. I would love to see more detail on this. Looks pretty straight forward. Is the radius adjustable. So if you wanted 9.5 on one board and 12 on another.

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  2. The radius is adjustable. I will try to get a video uploaded in the next couple of days that shows how it works.

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  3. After I read your post, I found this video on the Internet http://www.youtube.com/watch?v=IneRXf4J52I&context=C34ec4f5ADOEgsToPDskJZ0gTh1hAP4IDrzbCfyGNM a look at time 2:10, the guy made a contraption, What do you say?

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  4. Boy I wish I could work that fast! Actually, my first two jigs for the fretboard radius were just like the one he uses. The problem I had with both was a lack of stability. I tried several different approaches with springs, added weight and a wider router mount, but nothing worked to my satisfaction. The slightest jiggle and the fretboard was history. So far, the new jig seems to work great, but I have some more testing to do.

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  5. What you think of this one!?

    http://www.youtube.com/watch?v=TLU0TYPK80w&feature=related

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  6. Ryan has some cool jigs. I really like the one he uses for carving the neck's back contour. One of the things I've learned about jigs is that the more the tool has to move, the great the risk of screwing up your work. Most radius jigs require the tool to move back and forth and side to side in an arch. My jig works a lot like this one:

    http://youtu.be/2-JOnDoJp-M

    Very minimal tool movement and in only one direction.

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  7. Hi,
    Would be interested too in see how your jig works too, would be helpful when I build a version of your Raizer guitar in the spring (in UK) from the plans I bought from you last month.

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  8. Yes, there is interest on the plans and on the video. Cheers

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