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Anyone care to share your homemade radius blocks and how you made them?

I'm getting ready to give it a go but I haven't decided how I want to do it yet. What I really want to do is set up my drill press planer to be the exact angle to give a 12 inch radius. Only problem is I don't know how to calculate that angle. If anyone knows, do share if you feel inclined. This would be the quickest way to make one.

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http://www.tinyhouseandland.com

...do you mean 12 inch radius...?

I've considered making them myself several times. But the wooden blocks sold by StewMac and LMII are so cheap, I can't justify the time and effort to make a jig/jigs specifically for this task, nor the time to actually make the radius blocks themselves. It's a time versus money thing. They're cheap enough that it's a better use of my time to just go ahead and buy them. YMMV.

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Mike

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

Yep, ya got me. Thinking too hard.

Are there any mathematitions on the forums? Somebody somewhere has an equation for the degree at which to tilt a circle of radius A to become radius B. I feel like it's really simple, I just don't know how to do it.

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http://www.tinyhouseandland.com

The easiest thing to do would be to use a router. Mount it to a board with a pin at 12" from the cutter. Make sure the pin also goes through your work table so that it serves as a pivot point. You can then take a piece of maple (or any other hard wood) and clamp it so that the router cuts a swath through it, creating a 12" radius arc. Keep moving the maple so that you end up with a bunch of sections with a 12" arc. Glue those pieces together and voila!

Angling a round cutter will give you a different curve, but I doubt it's a section of a circle.

Mike

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Mike Lindstrom

If you want to draw a perfect 12" radius, get a piece of yarn/string, cut it exactly 12 inches, put a pencil on the end, attach the other point to a fixed section, put paper underneath, stretch the string out and go in a circle around your fixed point, any section of the circle drawn will be a 12" radius. Use any portion of that you need.

I hope that answers your question, I'm not exactly sure what you're asking.

I broke down and bought one from LMI. The handy ones with two sides. I can keep myself busy till they get here.

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http://www.tinyhouseandland.com

Good deal! I have the Stewmac variety, but am planning to buy a couple of the ones from LMI so I can cover all my bases. The double sided ones look like a really a good deal, IMHO.

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Mike

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

A simple radius can be done using a table saw and blade and running a flat piece of material skewed across the blade. Radius will be determined by the angle across the blade and the diamter of the blade.

Hope this helps.

Kevin

The table saw blade at a skew also does not make a circle but an ellipse.

Making radius blocks takes an investment of time in jigs and tooling. Unless you plan on mass-producing them or something, I don't think it's worth it to build your own radius blocks. If you want to invest your time in building a radius block for yourself, that time is better spent building a jig that will put a radius directly onto your fretboard, imho.

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David Morris

Also, with all due respect, I don't think this works. I came across some guys suggesting this idea when I was developing my plans to make radius blocks. Here's the problem. As you increase the angle to which you skew the wood across the table, you increase the radius you create. (I know it's elliptical, but I doubt many people would ever know the difference on an actual guitar.) The greatest amount of skew you could possibly achieve would send the wood directly parallel to a straight cut. You would, in effect, be running the wood horizontally across the table saw, rather than vertically, as you normally might. This would give you the largest possible radius the blade can achieve. And that radius is the exact radius of the table saw blade. For most of us, that's a 10" radius. And I don't think it would work very well. Table saws are scary, even when they're used as intended.

Correct me if I'm wrong.

Incidentally, the drill press planer works, if an elliptical radius is ok. I think most people set it up with trial and error, measuring the radius they create after the cut it, and then making small adjustments.

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David Morris

http://www.rockler.com/articles/cutting ... -saw-1.cfm

http://www.rockler.com/articles/cutting ... -saw-2.cfm

Kevin

Yes, I know. It's a common technique used to produce molding. But most radius blocks range between 7.5" and 20". I misspoke earlier when I said a 10" blade can produce a 10" radius. I'd forgotten that 10" is the diameter of the blade, rather than it's radius. You can produce a radius no greater than 5" with a 10" blade. In order to produce a 20" radius, you'd need a blade no smaller than 40" in diameter. So unless you have a circular saw mill like the one pictured below, it's probably not a practical solution.

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David Morris

[Edit] Nevermind, been said twice before. Not sure why it's still being discussed.

Point taken. The truth is that I've been working on some radius block ideas for about six months, and it's gotten slightly interesting to me. Only slightly, of course. It's radius blocks, after all.

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David Morris

Plus I would be very nervous running a piece of wood across a tablesaw blade rather than as intended... The potential for the blade to grab the piece and throw it sideways is too high.

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