Official Luthiers Forum!

I have gotten a few requests for plans and dimensions for my binding jig, so I finally got around to it. I only operate in the metric system, sorry! To calculate the dimensions in inches, just remember that 1" = 25,4 mm.

I made mine with materials I had on hand, and that was some cheap bearings, threaded rod and some 15 mm acrylic scraps. Some people have commented that acrylic is difficult, even scary to shape and that a polycarbonate like Lexan is better for a jig like this. I don't find acrylic that hard to shape, but it can chip if you are not careful, so wear goggles! Of course, you can also use plywood, aluminum or whatever, and you will have to adjust it to your trimmer and your needs. I use a 400W Hitachi trimmer.

Here is a quick and dirty elevation (I can e-mail the .pln or .dwg or .dxf to anyone interested).




Here is how I operate the jig:

The binding rabbet width is adjusted by moving the bottom part (movable "shoe") in or out in a rabbet in the top part (base plate). A wing nut and a screw that is tapped into the movable bottom part secure it to the fixed upper part. The binding rabbet height is adjusted on the trimmer base adjustment screw. I use 1/4" carbide down cut bits (from LMI) with this jig, so the cut is very clean. The bit protrudes through a washer glued to the base which makes sure you only register on the edge of the top or back plate, meaning the plate’s radius will not interfere with the cut. I clamp this jig in a vise and rotate the guitar.

If you are clever you can probably also build a micro adjuster of some sort for the width adjustment. I just loosen the wing nut and tap lightly and test on scrap, no biggie.

Here are a couple of snap shots again:
Front:


Side:

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Rian Gitar og Mandolin

Thanks...I'm "dreading" the day when I take a router bit at 30,000 rpm to my nice closed box...Build #1 is all about nerves and mold/jig building.

Thanks again,
JP

Arnt, that looks very cool. The washer is a nice touch. I think I might have to make one! Thanks!

Mike

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Mike

"The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Shoosh." The Stranger

Thank you very very much Arnt! Just in time for my binding session, i will attempt building it , you rock dude! File saved!

Serge

[QUOTE=Dread1916] Thanks...I'm "dreading" the day when I take a
router bit at 30,000 rpm to my nice closed box...Build #1 is all about
nerves and mold/jig building.

Thanks again,
JP[/QUOTE]

JP,

You sound like me when I got my new bandsaw. It sat in the workshop for
about week and Id walk past it and look at it nervously imagining limbs,
fingers and bits of guitar flying all over the garage the first time I used it.

Now I cant do without the thing. I used to fear routers also but now own 5
of the things.

Routers are great for cutting binding/purfling channels. There are a few
little tricks to making the job easier and Arnt's jig is one of them. The
direction you make your cuts is also important to minimize tear out...see
Stewmac's website for instructions on same or ask on this forum for
advice.


Cheers Martin

[QUOTE=Arnt]just remember that 1" = 25,4 mm.[/QUOTE]

And that 25,4mm = 25.4mm

Arnt,

I saw the photos you posted last year on MIMF and built one from those. Worked extremely well. It was nearly free, since I too used materials I had, though my acrylic was only 1/8" thick, so I glued them up double to get 1/4", or about 6.4 mm.

I found it helpful to hold it mostly by the movable shoe when routing, only holding the laminate trimmer lightly to support its weight. It was bery easy to control that way. The guitar body was in a vise made with pipe clamps a la Sylvan Wells. I had considered holding the jig in a vise by the shoe and rotating the guitar body, as in the Taylor video, but the other way seemed to work. How do you use yours?

Thanks for sharing, Arnt!

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now known around here as Pat Foster
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http://www.patfosterguitars.com

I like that jig!!!!!!!!!!

Dread, I use the Dremmel 400XP with the StewMac base and binding guide attachments. I am not familiar with the Laminate Trimmers, but to let you know I run my Dremmel pretty low on the RPM's and take small bites and move slowly around the surface. Have not had any problems. I do run uphill to prep the upper and lower bout turns and then run downhill all the way around.

Mike
White Oak, Texas

Thanks Arnt

Thanks Bud! It's saved to the HDD!Billy T38861.6103009259

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Billy Dean Thomas
Covina, CA

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

[QUOTE=burbank]
I had considered holding the jig in a vise by the shoe and rotating the guitar body, as in the Taylor video, but the other way seemed to work. How do you use yours?
[/QUOTE]

I clamp mine in a vise and rotate the guitar, I find this gives the best control. I took the Martin factory tour last summer, and I noticed they also do it this way so it is certainly a tried and tested method.

Thanks for the comments, guys!

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Rian Gitar og Mandolin

Pat, did you have to make any modification to Arnt's jig to route free hand, i mean to be able to do the back taper at the upper bout where this taper is bigger?

And also, do you guys see the need to add a piece of UHMW to the jig for the taper around the guitar?

SergeSerge Poirier38860.3059606481

Serge, if I understand your question correctly, you are asking if 2 mm thick washer gives enough clearance between the bottom of base plate of the jig and the domed guitar back so this part will not to interfere with the cut. I use a 15' back, and I have not had that problem. The jig registers off the sides and a very small area close to the edge of the back plate, the taper of the back relative to the sides does not come into the equation. If you use an extreme arch, like an archtop without a recurve or something, the size of the contact area on the back might be a problem. In that case I would use a smaller OD washer, perhaps stack up a couple. If you look at the drawing, you will see the base plate is very short towards the side that overhangs the guitar back (or top), this was the reason for that design decision. If you keep the contact points firmly to the guitar you should not have a problem.

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Rian Gitar og Mandolin

Thanks Arnt!

I'm going to try and build one when I get the chance.

Thanks for your explanations Arnt, i was wondering and probably assuming that the washer might come in contact with the edges if i was to use your jig for free hand routing but as you mention, if the bearings are well registered to the side, only the bit will touch the wood so everything should be fine for me as long as i take the time to well position the jig and go slow right?

Sorry for my ambiguous question, it was my first or second post of the day, after my first sip of coffee!

SergeSerge Poirier38860.3851851852

Serge, the washer IS a contact point, it is the ONLY contact point on the top or back of the instrument! That is it's purpose; it contacts the edge of the back or top plate and lifts the rest of the jig off the instrument so the arch of the plate will change the angle of the cut.

So there are 3 contact points in total: One on the top / back (washer), two on the side (bearings).

Make sense? (eh, you don't speak Norwegian by any chance, I have a feeling I'm not being terribly clear...)

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Rian Gitar og Mandolin

Sorry for my confusion Arnt, Monday mornings i guess! All clear now bud, i guess my French, your Norwegian, our English and my lack of coffee this morning made it all foggy!

I'm sure it will be the best thing that will help me do this scary step so thanks for taking the time with this " not so awakened Bear " Arnt! I really appreciate what you did!

Regards

Serge

Thanks Arnt
Cheers
Charliewood

Thanks Arnt. We really appreciate your taking the time to draw up the plans for the rest of us.    

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Don Atwood
Arlington, VA

Arnt,

How did you know that I bought a Porter-Cable 310 yesterday! That's amazing!

Does the washer have a tendency to mar the wood?

Love the design, thanks!

Steve

Hi Arnt,
           Thanks for your post.
I made a similar jig some time back , and like Pat find it easier to use it hand held and move around the guitar.
I have found with such a small "donut" , it can easily be tipped sideways a little,and thereby alter the depth.
When it is going, it is difficult to feel the donut touching ,or seating level (both sides of the donut on the top or back) I have made my donut a little bigger to help this , which of course ,varies the depth of cut,but only marginally.
Have you had any issue in this regard ?

B.T.W. , I find the jig very succesful , but am careful about keeping both sides of the donut in contact

The other issue relates to routing the back mainly. Because guitars have a wedge shape (say 4" at the end graft and 3" at the heel ), when the jig's donut sits flush on the back , it is slightly tipped. This is no problem in itself , but as it moves around to say the waist area . the two guide side bearings don't contact the side in a 90 degree manner. Depending on which direction you are routing , either the top or bottom guide bearing contacts the upcoming curve before the other. and thereby ,tips the jig off correct angle making the width of cut narrower or thicker ( depending on which direction you are routing).

To combat this , I have put a tiny shim on one side of the donut, so that the jig sits square to the sides curvature. The thickness of the shim would depend on how much of a wedge the guitar has .

I hope I have made myself clear here.Difficult for a Kiwi

Your comments and experience are welcome thanks Arnt

Regards , KiwiCraig

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CRAIG LAWRENCE of AUSTRALIA
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[QUOTE]I have made my donut a little bigger to help this , which of course ,varies the depth of cut,[/QUOTE]

Do you mean thicker or larger diameter, Craig?

[QUOTE]I hope I have made myself clear here.Difficult for a Kiwi[/QUOTE]
I thought New Zee's spoke English(and sheep)?

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Billy Dean Thomas
Covina, CA

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

G'day Billy,
              I have made my "donut" about two inches wide . This way I can feel the donut seated both sides and it's not so easily tilted sidesways . The wider the "donut" , the more depth variation . Mine is a slight compromise and the depth variation is very slight (about .5m.m. at the waist) It's not noticeable.
I first built mine after reading the Jim Williams book where he has a plan of his version , although his has a wide footprint. I also tapered the front of the donut to allow for the plate's arch.
It works very well !

Hey Billy! ,,,,I know all the sheep jokes...


Baa Baa   KiwiCraig

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CRAIG LAWRENCE of AUSTRALIA
_____________________________________________

Thanks Craig!

Sheep jokes? I didn't know there where any sheep jokes.

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Billy Dean Thomas
Covina, CA

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

Hi Craig, the jig can be a bit hard to balance if you use it hand held, as it is a bit top heavy. The bigger donut might help a bit, but as you say, the bigger the contact area is the more the cut will be influenced by the geometry of top or back plates. This is the reason I like to clamp the jig and move the guitar; I feel it is easier to hold the guitar straight than the trimmer + jig, and the small contact area between the steel washer and the guitar is not a problem when you use it this way.

As far as sheep jokes, I can only think of one, but I do not know how appropriate it is for a polite place such as this...

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Rian Gitar og Mandolin

[QUOTE]As far as sheep jokes, I can only think of one, but I do not know how appropriate it is for a polite place such as this... [/QUOTE]

None of them are appropriate for any place, I'm afraid!

_________________
Billy Dean Thomas
Covina, CA

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