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Tracy,

If you had your little angled pieces with the pins angled the same direction it would make it more accurate. The centerline would still be about .005" off, but would be paralell to the actual centerline. Having it the way pictured makes your constructed centerline cross the actual centerline on an angle, thus magnifying the error at the bridge.

Just a thought.

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Horton, MI

Don,
Thanks for the response! I like your idea a lot, but it seems that it limits the customer to the same jig as the Charles Fox jig. However, it did give me another idea that may work. I'll have to discuss it with my partner. Thanks!
Tracy

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Tracy
http://www.luthiersuppliers.com

Don's idea would work and not limit you to a single size.
Place a thin slot along the center line. Screw your side thing into it.
Make it so it is perpendicular to the center line and doesn't swivel. If it only
slides the direction of the neck, it would work fine. Slide each one until it
contacts the sides.   I will try to draw it.

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Andy Z.
http://www.lazydogguitars.com

Andy,
I see what you are saying, but I'm not sure it will work because the wings are wider than the fretboard. Now, if you made the wings able to move in and out, and slide in the small groove, AND you made the main base have 2 areas that were slanted(say from the first fret to the 5th fret, and the 7th fret to the 12th fret, then you just slide the outside contacts wider or smaller, then tighten a knob, then slide up the neck til it contacts it. That is what I invision, and I think it allow multiple neck sizes. Not sure I'm explaining it very well.
Tracy

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Tracy
http://www.luthiersuppliers.com

If you used the x in the 2 places on the jig, it WOULD lock it in and there would be no room for rotation. If was only on one end, it will still have a margin of error. Using the 2 x's would solve the issue and it would be precisely in the middle.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

[QUOTE=j.Brown] If you used the x in the 2 places on the jig, it WOULD lock it in and there would be no room for rotation. If was only on one end, it will still have a margin of error. Using the 2 x's would solve the issue and it would be precisely in the middle.
-j.[/QUOTE]

No, that wouldn't guarantee each to be on center. Each pivot point needs to be able to line up directly over the centerline of the fretboard independently. If it's off on one end, the whole things off.letseatpaste38951.5399537037

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Jonathan Kendall, Siloam Springs AR

Tracy
I know the wings are wider than the fretboard, but if you made each set of
wings a different width and they slid in a slot. (One near the 2nd fret or so
and the other around 9. The would eventully wedge to the side of the
fretboard as it gets larger. Make sense.   The wings would slide down
towards the bridge in each slot until they contacted the sides of the
fretboard.

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Andy Z.
http://www.lazydogguitars.com

I think you need each edge locater to be on a threaded rod that would be tightened with left and right handed threads like this one item number 94455A112 from     McMaster Carr Let me know if you need more help.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

-deleted-j.Brown38951.6023726852

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

Make each end like a self centering dowel jig. As you clamp it to the fretboard it would center it.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

[QUOTE=j.Brown] If you used the x in the 2 places on the jig, it WOULD lock it in and there would be no room for rotation. If was only on one end, it will still have a margin of error. Using the 2 x's would solve the issue and it would be precisely in the middle.
-j.[/QUOTE]

Very Good idea too...and would work very well.

My idea was to have two slots running parallel to the centerline in two locations on the template. The grippers would slide up and down and grab the neck in two locations. The adjustable X's may be an easier way.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Someone here on the OLF made up and sold a bunch of centering jigs a couple years back. They are of clear plastic with two sliders that wedge at locations like Andy describes above. There was no slot for the sliders, they guided off the sides of the straightedge which had a CNC machined centerline.
Nelson

Nelson,
That was Bob Pittman, and he sent the plans to me to make them also. However, it only works with limited sized necks. I wanted to deliver something that works with a large range of neck sizes. My partner tells me he has a fix, but he's on the road now and will not be able to do it until Sunday or Monday. I'll keep you all posted. Thanks everyone for the great suggestions!
Tracy

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Tracy
http://www.luthiersuppliers.com

Tracy--Looks like you could use a little pair of CNC'd plexi gear quadrants meshed to accomplish the self-centering. Machine gear teeth on about 90 degrees on one side of the pivot point with an arm on the other side with a peg extending down over the fretboard. You could hold tolerances snug to eliminate any play.
How cool would that be! CNC really shines on something like this.
Nelson

Steve, Do you mean kind of like this? My plastic work on this
prototype was a little suspect, but the jig works very accurately.
BarryDaniels38952.0343055556

Barry, what a cool jig!

I've finished the geometry to figure out what the correction to the towards-the-nut side span should be on the swivel arm, considering a fixed length on the other side. The correction is larger than I would have guessed - larger than just tape thickness. I've pm'ed Tracy asking for the distance between the pivot and the contact point on the existing jig, so I can compute real numbers based on a few guitars sitting around here.

The solution is programmed up in Matlab - I can send the code along to anyone who wants it. It's transparent enough to translate to whatever you prefer to work with. (I'd write a java applet, but I don't know how.)

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Jim Kirby
kirby@udel.edu

Barry--I wondered if you were reading this thread! I like the self-clamping feature of your jig also.
Nice work! Great minds at work here.
Nelson

I made my prototype using the hardware from a small wood handscrew clamp. It does act like a clamp, but it also tracks the centerline well. It also works on necks of various widths. I was gearing up for a production run, but when I heard that Tracy was coming out with his version I went back to making guitars.

Barry, maybe you could team up with Tracy and solve the problem with the jig he has. Yours looks like a fairly simple solution to the problems with Tracy's jig.

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Dave Rector
Rector Guitars

Dave,

I already contacted Tracy, but he told me that they have the problem solved.

I'm not sure what the solution is at this point, but my partner says he is 99.9% sure he has a fix that will require us to remake the jig, but not too much enhancements to it. I'll have to wait until Sunday or Monday to see what it looks like. I'll keep you all posted. Thanks all for the many wonderful ideas. He didn't even listen to my ideas, as he had already worked it out before I have him suggestions. So we'll see.
Regards,
Tracy

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Tracy
http://www.luthiersuppliers.com

Tracy, I received my jig today. As usual the jig itself looks very nicely machined. You guys do good work.

I'll be waiting for the resolution of this minor glitch.
Thanks again for providing all the great products!

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Dave Rector
Rector Guitars

[QUOTE=BarryDaniels] Steve, Do you mean kind of like this? My plastic work on this
prototype was a little suspect, but the jig works very accurately.
[/QUOTE]



This is exactly what I was envisioning. This makes a lot of sense and would be very to use. Good jig, Barry.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

[QUOTE=BarryDaniels] Steve, Do you mean kind of like this? My plastic work on this
prototype was a little suspect, but the jig works very accurately.[/QUOTE]Exactly like that. That looks good!

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.