a 'universal' fret slotting jig for the one-handed luthier

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Bob Hammond
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a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Hi,

Some people may remember that last summer that I fell off my bicycle and busted a wrist. Then, I was apprehensive about using electrically powered tools, and so I started developing hand-tool skills, and made a useful fret-slotting jig for conventional fingerboards.

Now, I'm interested in making a fan-fretted 'multi-scale' fingerboard, and so I made another jig. it works pretty much like the original, but I see that there are unnecessary parts. It doesn't need to be so complicated. Just look at the pictures and think about what isn't important to the mechanism of action:
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jiggery2.jpg
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

My apology, for failing to credit the person(s) who created the website for calculating and drawing the pattern. That's most important part of this jig:

Fret2find2D http://www.ekips.org/tools/guitar/fretfind2d/
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Peter Wilcox
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Peter Wilcox »

Bob Hammond wrote:My apology, for failing to credit the person(s) who created the website for calculating and drawing the pattern. That's most important part of this jig:

Fret2find2D http://www.ekips.org/tools/guitar/fretfind2d/
His name is Aaron Spike, and he's a web developer at Martin Luther College in New Ulm, MN. I had a brief email correspondence with him earlier this year when his site was down, and thanked him for making such a useful tool as Fretfind2d available.
Maybe I can't fix it, but I can fix it so no one can fix it
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Peter, thanks for the info. I'll send him a note of appreciation.
Mark Fogleman
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Mark Fogleman »

Looks good Bob! What are you using for the depth stop?
Jason Rodgers
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Jason Rodgers »

Bob Hammond wrote:Hi,

Some people may remember that last summer that I fell off my bicycle and busted a wrist. Then, I was apprehensive about using electrically powered tools, and so I started developing hand-tool skills, and made a useful fret-slotting jig for conventional fingerboards.

Now, I'm interested in making a fan-fretted 'multi-scale' fingerboard, and so I made another jig. it works pretty much like the original, but I see that there are unnecessary parts. It doesn't need to be so complicated. Just look at the pictures and think about what isn't important to the mechanism of action:
Can we get a look from the other side? I'm wondering how the wood blocks slide on the guide bar: as the angle gets further from 90, those two points will grow wider.
-Ruining perfectly good wood, one day at a time.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Mark, the depth stop is just a piece of windowscreen frame. (It's what I had at hand). It's quite smooth and it stuck well to the double-stick woodturners' tape.

Jason, I'll take another pic for you.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Here's a couple more pics. By the way, this is also a miter gauge beam for a table saw sled.


The fence angle here is 25 degrees, which should be enough for most work.

The clamp is made of two pieces, and the inner one has a Tee nut embedded in it. The compression spring on the T-bolt makes the beam a little easier to use but is not necessary. The front tracks isn't needed either ; a simple pivot bolt would do. I may glue down sandpaper to the base but I don't think that is necessary either.
Attachments
IMG_20150928_090008-1.jpg
IMG_20150928_090023-2.jpg
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

It occurs to me that it might not obvious, about how to use this thing.

The saw is a Vaughan Bear Saw BS250. The manufacturer states that the kerf is 0.0226", which I believe because it may be necessary to widen the slots 'freehand' so that installation of the frets doesn't curl the fingerboard.

The manufacturer's URL:

http://www.vaughanmfg.com/shopping/Depa ... -Saws.aspx


Here's some more pics:
Attachments
Check to see that the paper template is straight on the workpiece.
Check to see that the paper template is straight on the workpiece.
A straightedge is placed on the magnetic strip, and the workpiece adjusted to match the fret marker line with the straightedge.  >Be very consistent about how they are aligned to each other.<
A straightedge is placed on the magnetic strip, and the workpiece adjusted to match the fret marker line with the straightedge. >Be very consistent about how they are aligned to each other.<
Fingers may be gently pressed to guide the blade along with the magnetic strip.  &gt;Note that the rip teeth are shielded -- they're very sharp and will cut flesh easier than wood.&lt;  The other hand powers the saw, and lets the teeth do the work.
Fingers may be gently pressed to guide the blade along with the magnetic strip. >Note that the rip teeth are shielded -- they're very sharp and will cut flesh easier than wood.< The other hand powers the saw, and lets the teeth do the work.
So far, so good.  You can feel/hear when the depth-stop has limited the  cut.  The paste wax can be used to reduce friction of the sawblade against the fence.  (This is a good idea when handsawing anything.)
So far, so good. You can feel/hear when the depth-stop has limited the cut. The paste wax can be used to reduce friction of the sawblade against the fence. (This is a good idea when handsawing anything.)
Note that the saw kerfs are parallel to the marker lines.  This is not a problem; it is a result of the difference in thickness of the straightedge and sawblade.  It is a problem if the offset is inconsistent -- this reveals inconsistent alignment of the straightedge relative to the marker line, or overworking of the saw.  A sharp blade and light stroke are what's needed -- not brute force.  I would dedicate one blade to this purpose.
Note that the saw kerfs are parallel to the marker lines. This is not a problem; it is a result of the difference in thickness of the straightedge and sawblade. It is a problem if the offset is inconsistent -- this reveals inconsistent alignment of the straightedge relative to the marker line, or overworking of the saw. A sharp blade and light stroke are what's needed -- not brute force. I would dedicate one blade to this purpose.
Jason Rodgers
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Jason Rodgers »

These are the pics I needed to make sense of the fence. Thank you!

One of these days, I'm going to attempt a multi-scale saw that uses a similar fence, but with pins for feet that register in scale "rulers" with holes at each fret. (Don't know if that makes sense, but it looks pretty cool in my mind's eye.)

By the way, I also like your use of a thin metal ruler to align the fence with the template. I eyeball it (my fence is only 1/8" above the fretboard), but that's another 5 seconds to make sure it's lined up as accurately as possible.
-Ruining perfectly good wood, one day at a time.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Jason, there's an easier way to align standard perpendicular frets, that I used for the previous jig. I laid a piece of tape to one side of the fence and made an indicator mark on it about 1/4" away from the fence. Then I lined up each fret marker exactly with the indicator line, and then sawed away. This just displaced the slots 1/4" to the side of the template line, and perfectly spaced.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Jason, here's a link to the previous post about the standard jig. The second picture showes the tape and index mark:

http://www.mimf.com/phpbb/viewtopic.php?f=12&t=3378

Oh, and I've found that it's faster and easier to punch the alignment holes in the template sheets with an ordinary office paper punch, instead of using a knife.
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Bryan Bear
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bryan Bear »

Nice jig! When I align my saw guide to my wfret template (parallel frets) I use a marking knife and stab it into the printed line then slide the guide up to the knife edge. I find it easier/more consistent than trying to line my guide up to the printed line. I like your ruler trick to solve this. For multiscale, I would be temped to try sticking a pin in both ends of the line (getting the point as close to the center of the line as possible then sliding it over until the pins align with the fence. That may be more effort than it is worth though. . .
PMoMC

Take care of your feet and your feet will take care of you.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Bryan, if you look back at the picture of the original 'standard' jig, you'll see that the index mark is a knife slash in the tape. This is more precise than stabbing each fret marker line on the paper template and then . There is less parallax, and it's very easy to see.

If I can figure out how to make such an index mark for this jig, I'll do it, and stop using the straightedge.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

I'm a bit amused that no one has noticed that the paper template was plotted for 5 strings, but I can understand that it's difficult to see the short scale lengths (23-24) in the photos. But that's why I made the jig -- it's a thing that can't be bought at the hardware store.
Jason Rodgers
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Jason Rodgers »

Bob Hammond wrote:I'm a bit amused that no one has noticed that the paper template was plotted for 5 strings, but I can understand that it's difficult to see the short scale lengths (23-24) in the photos. But that's why I made the jig -- it's a thing that can't be bought at the hardware store.
I don't know if any banjo players could be sold on the multi-scale! :)
-Ruining perfectly good wood, one day at a time.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

I don't know if any banjo players could be sold on the multi-scale! :)
Lately, I haven't seen many banjos with a 23" or 24" scale. But maybe it's different in your neck of the woods.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

(Maybe next time, I'll put up a pic of a worn-out $2k Bridgeport mill that was retrofitted with motor-servos and controlled by a $3k CNC system, for production runs of 10-500 identical fingerboards.)

Nah.
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Jon Whitney
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Jon Whitney »

Bob Hammond wrote:
I don't know if any banjo players could be sold on the multi-scale! :)
Lately, I haven't seen many banjos with a 23" or 24" scale. But maybe it's different in your neck of the woods.
Really? I think short scale banjos (23 - 24" compared to 26 - 27") are becoming more popular these days, at least among open-back old time players. They are more easily tuned to A and D, the keys fiddlers like to play in.
Bob Hammond
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Re: a 'universal' fret slotting jig for the one-handed luthier

Post by Bob Hammond »

Jon, long time no see. Are (Were) you at Orange Brick University in the vicinity of 30-33rd & Chestnut/Market?

This little thingie will be a 5 stringer tenor guitar (I hope).
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