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Hi all,

Been lurking for a while and in he process of my first accoustic (have one electric built). Anhow I have been able to answer most my questions by searching previous posts, unfortunately have not been able to find an answer to this one.

Looking at using a T-planner to create raduis sanding blocks to radius the fret board. I do have one from Steward McDonald (purchased it for my electirc build), but would like to use a different radius. So the question is does anyone have the table tilt angle (or formulae) to create the desired radius ?

Thanks,
Eric

Neat idea. I searched "t-planer (not planner) radius block" on google and came up with a tutorial on projectguitar. I guess I shouldnt link to it though.
Warren.

Welcome to OLF Eric!

If you're talking about using the Safe T Planer to make a radius block for sanding your fretboard radius, I set the angle on my drill press table at I think about 6 degrees. That angle will vary depending upon the specific radius you plan to use on your fretboard.

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Bill Hodge


One does not simply, own enough guitars!

You may want to keep in mind that if you do this, the cross section of the cut will turn out a section of an ellipsis, and not a circle.

Sondre

Actually, if you take care to set up the center line precisely it cuts an excellent radius. I've made a couple and used pieces of scrap to adjust my jig until it was cutting a true circular radius that tested perfectly with my radius gauges. It is however limited by the size of the safe t plane as to how wide you can go. And you can't just fly through the setup, it takes some time to get it precise.

On a different note, Sondre, your avatar looks extremely painful.

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Bill Hodge


One does not simply, own enough guitars!

Chris, good point! I figured I'd mention it in case someone had any opinions on it

Bill, It's good to hear that you've been doing it successfully! Maybe I'll give it a try myself.

Let's just say that I am blessed with a dexterous left hand

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Bill Hodge


One does not simply, own enough guitars!

Man!!!! Must take for ever to clean ur nails........you would probably stave if you lived with my mother.

What the....



Eric: Safe-T planer at 2.75" dia, I'm getting about 2.5º (2.46º) for a 16" radius, but my trig is a little rusty. You might want to try it out first.

What radius are you trying to get?

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

One thing you might consider when using this method, what your really generating is a parabola. If you use to much of the cutter diameter you'll get errors in the profile.

I don't know how wide of a sanding caul you're making but StewMac's are 2.75 wide that will surely give you a parabolic shape out at the edges of the caul. Either, use a wider cutter, like a trammel cutter/fly cutter, which I wouldn't be too sure of using on a drill press(depending on size and rigidity), or find a wider cutter.

If you use a larger cutter the angle changes, of course.

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)

Thanks everyone,
I guess it probably helps to do research if you spell the word correctly

I was looking at 16' radius , but also thinking at doing a compound radius (using mutiple blocks), might have to rethink this.

The answers got me thinking, what is the problem with an ellitpical curve (still trying to get my head around whether it's parabolic or ellictical) is it because it wont feel right? has anyone ever tried different arc shapes ? looking at my bent finger I'm not sure it forms a real arc (or that it's even symetrical) .
Just curious.

I am planning to make my blocks out of individual pieces of scrap 3/4" plywood with the radius and finger channels bandsawn into the profile. 11 of them glued together will form a ~8" sanding block. Even out the rough spots with coarse sandpaper.

Not sure if you have any scrap yards around, but it's pretty easy to make these on a 24" diameter or larger pipe depending on what radius you want. A piece of 40 or 60 grit taped to the pipe, an inverted piece of angle iron held parallel (self centering) on the pipe as a fence, your wooden block and some elbow grease makes a perfect radius in a few minutes.

Make a constant radius sander by glueing two 1/4" dowels parallel & 3" apart down a flattened face of a 3' pc of 4 x 4. Spread fresh bondo between and run a radiused template down the dowels to shape the bondo. Stick on sandpaper & voila!

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Dave
Milton, ON

Now THAT is one slick idea. Good on ya Dave! And since it involves Bondo, I'm sure Padma will like it too.

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Bill Hodge


One does not simply, own enough guitars!

Thanks Bill....pretty sure I didn't think of it!

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Dave
Milton, ON