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I have a new setup for cutting binding ledges, and I thought I would share it with the group.

You know how sometimes we get to say "I built it myself, it only cost $15 in materials, and it works great"? Or, we get to say "it cost a lot, but I didn't have to build anything, and it works great"? Well, this was neither one. This setup cost some money, and I had to build something. But, the testing is very impressive so far, so I think it was worth it. Maybe you can get some ideas from it.

Here is a photo:



Here are some views from the sides:





And one from above:



Essentially, it is a LuthierTool self aligning binding ledge jig, attached to a Bishop Cochran router base (which houses a Bosch Colt), which is attached to a tower I built. The guitar rides in an LMI carriage (not shown).

Before I put this together, my favorite binding ledge system was the LMI tower system. It gets almost everything right. I love the fine tuning that the screw-out donut gives for the across-the-side depth of cut, the linear motion track for the vertical movement of the router carriage, and the coil spring counterweight. I also love the reliability of the across-the-plate depth of cut provided by the bearings.

The only thing I don't like about the LMI system (or any bearing system) is that you are limited by the sizes of the bearings that are available. I sometimes want to use wide purflings on the top. That is not easy with the limited bearing sizes that are available for the LMI and StewMac cutters.

I have used other types of continuously adjustable systems that give a lot of control over the across-the-plate depth of cut. But those tend to have a stationary finger that defines the depth of cut relative to the cutter, and that only works if you keep the cutter and finger perfectly perpendicular to the side. I know people make these systems work, but I am not a fan. That's probably more about me than the jig.

Anyway, I had a chance to buy a used LuthierTool self aligning binding ledge jig, and I grabbed it. This jig solves my problem with continuously adjustable systems, because it uses two bearings (one concentric to the cutter, the other offset by an adjustable amount) to always have a constant depth of cut, despite the guitar side's orientation to the cutter. It is pretty slick!

This jig attaches to the router via a collar, just like a Porter Cable template bushing. I started looking at designing a custom base (which is not hard, if you have the right sized Forstner bits). I also was not feeling great about giving up the across-the-side depth of cut precision I get from the LMI adjustable donut. Then I looked at my Bishop Cochran router base, and I had a thought. The router base comes with a base plate designed to take Porter Cable template bushings. It also has outstanding depth of cut (in this case, across-the-side depth of cut) precision. And if I removed the fence and the bolts that lock the fence, it would have several secure attachment points. This was looking interesting.

I bought an inexpensive linear motion track on Amazon and designed a cradle for attaching the router to the track. With the fence removed, I was able to use the router base's through-holes for the fence rails, and the side set screw holes, to mount the router base to the cradle. I mounted the track on a tower. The linear rails cost about $32; look for 300mm miniature linear rail guides. Here are some close up photos:







For the counterweight, I decided to go simple; I attached some cheap pulleys and connected the router cradle to a counterweight on the back side of the tower. This is a plus, in that it allows me to fine tune how much counterweight I need. The weights are garage sale barbell weights, 1.25 lbs. each. Three weights, plus friction, give me just the right amount of counterweight for the router to apply a very light downward pressure on the guitar plate. Here is a photo of the counterweight:



For the guitar carriage, I am pretty happy with the one I bought from LMI. Some people struggle with theirs, but I like mine.

This setup gives me everything I want. The router stays perfectly vertical, with absolutely no slop. Using the right amount of counterweight makes sure the router neither dents the guitar top nor skates across it. I get fine, continuous adjustment of both across-the-side and across-the-plate depth of cut. And when I want to use the Bishop Cochran router base for other things, this all comes apart in a few minutes.

This is not for everyone. A number of other systems work just fine. But this one promises to be ideal for me.

Again, I hope this sparks some ideas for your own jigs.

Very nice! I think that having a good solid linear rail/bearing system along with the counterweight you have set up should make a much improved version of the "old standard" jig. Good job!

Dave

That's cool that you incorporated your Bishop-Cochran base into your setup. The adjustment for depth of cut on that is far, far superior to that of the Colt. And extra cool points for combining it with the LuthierTool jig. Nice. Do you have a close up photo of the business end under the base plate?

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Here is a view from the bottom, Jay. Let me know if you want to see more.



I should also clarify that, while you can have the power cord ride over the pulleys above the sash cord that connects the carriage to the counterweight, that adds unwanted friction, so in operation, I have the power cable off to the side. Also, I had to trim back the power cable's stress relief a bit, because it was in the way. I kept enough so that it still safe, but it is no longer bumping against the pulley.

A bit more on the linear rails:

You can go with a beefier, two rail system for roughly the same money, but for this job, a single rail works fine. The rail comes with a lot of holes for mounting. If you use screws with small enough heads, the heads fit into the rail and do not impede the travel of the blocks. If you want stops for the blocks (and you really should want stops at the ends), just use screws with heads larger than the holes. Easy peasy. I put an additional large headed screw near the bottom, because that keeps the jig just above the surface of my workbench when it bottoms out.

Thanks for that photo. I had completely forgotten about that second base plate that comes with the Bishop-Cochran. Now you've got me thinkin'.

What are you using for the bit?

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

1/4" downcut spiral. That's what LuthierTool recommends. The tests are coming out with nice clean ledges.

A bit more detail about the tower:

The base of the tower is 18mm Baltic Birch, bolted to my workbench through two dog holes. the rest of the tower is 12mm Baltic Birch, as is the carriage for the router. The two upright pieces have slits in the middle, and fit together like an X brace; the main body of the tower has a downslot, and the cross brace has an upslot. With the assistance of Kreg pocket hole joinery (fast and strong), this all went together very easily. It's very solid, but quite light.

Really nice setup Don. I have been thinking about upgrading my setup and have been looking at the LuthierTool self aligning binding ledge jig. How easy is it to set the across the plate setting and get the precise width of cut? Do you use a caliper to set this? Let's say you want to increase the setting by .005". Would you be able to hit the mark in one setting?

Barry--

Here is a link to a YouTube video that shows a great "ballpark" way to initially set the across-the-plate depth of cut, using the binding/purfling material as spacers:

https://www.youtube.com/watch?v=LnlZvzo10Eg

In a different video, Chris Klumper, the principal of LuthierTool, says that a full turn of the across-the-plate depth of cut adjustment knob produces a 1/32" change. His comment is right after the 3 minute mark:

https://www.youtube.com/watch?v=QipwrRDmkZM&t=202s

As an aside, let me give both a tip o' the hat to Chris for creating excellent products, but also a gentle wag o' the finger for lack of documentation. There ought to be a decent manual or user's guide for this tool, but none exists as far as I can tell.

Anyway, 1/32" = 0.03125". So, a quarter turn of the knob would produce about a 0.008" change, and an eighth of a turn would produce about a 0.004" change.

In my tests so far, I could feel my way and get pretty close, make a test cut, then dial in from there. The second test cut is dead on.

I don't think a caliper would be much good for across-the-plate depth of cut fine tuning, because the lower bearing sits a good distance below the router bit, and everything is moving around, thanks to the upper bearing. A caliper could be more useful for the across-the-side depth of cut. I can get that pretty close by hand, too, and then dial it in using the Bishop Cochran router base's depth adjustment.

In terms of financial impact, the jig itself costs @ $300 USD new. I bought mine used for a bit less. The tower Chris sells costs @$350 USD new. I like my tower better. Chris' body carriage costs @$300 USD new. I like the LMI one just fine, and didn't feel the need to replace it. I figure we all have body carriages at this point or can build one, and we can all build a decent tower. So, I would not pay for Chris' tower or body cradle (no offense to Chris). But the jig is worth the money, in my opinion.

You’ve successfully combined two of the nicest jigs I’ve had. The Bishop Cochran base and LT binding head. I love ingenuity. Thanks for sharing!


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The first video Don posted is extremely helpful in regards to setting the X-Y axis depth of cut with the LuthierTOOL jig.


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Nice bit of kit you've got there, I'm jealous

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Colin—

If anything, envy my luck at finding good used tools. The expensive bits (Bishop Cochran router base and LuthierTool binding ledge jig) I bought used.

If a person already had a laminate trimmer with good depth of cut adjustment, a few Forster bits for making a base that takes PC template bushings, some spare Baltic Birch, and money for the linear rail and the binding jig (the expensive part), a tower like this is not hard to build.

By the way, I keep mentioning the idea of making custom base plates for Porter Cable template bushings. It takes two Forster bits: 1 3/8” and 1 3/16”. Use the big one for making a ledge deep enough for the bushing lip, and use the small one for drilling through. Very simple.

I know, made one years ago, one of the "I built it myself, it only cost $15 in materials, and it works great" but thinking of upgrading from drawer slides to the linear bearings.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Colin—

I had plenty of drawer slides sitting around, and they would have worked fine, but the linear rail is much more precise. Absolutely no slop at all. I remember when these things were expensive, but the one I bought was very affordable ($32 USD). It’s a single rail, 300mm long, with two blocks. The blocks require relatively small metric bolts (m3-0.5), but those should be easy to find. Using one rail also fit well into my plan to use a tower that was a well supported “spine” of a single piece of Baltic Birch. I might buy more of these rails; I keep thinking of things they would be useful for. Don’t fail to use stop screws at the ends of the rail! If the blocks go off the ends, the ball bearings are exposed, and they don’t take much coaxing to come loose.

Very cool. I looked at that guide bearing setup pretty seriously a while back as it would be so nice to use fresh bits regularly without a big expense.

I seem to recall that someone had some accuracy issues when actually cutting binding channels but I can’t remember what they were. Anyone here remember?

Anyway be sure to re-post after you have bound a couple of guitars with it and let us know how it works. It looks great.

Thanks

Terry

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I'm making a copy of the Elevate binding jig.







Will post pictures when complete.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Actually the LuthierTool self aligning binding ledge jig itself seems a relatively simple design to fabricate if you have the machining capabilities.
In principle it's just a small horizontally adjustable bearing fitted (offset) on a plate with a large bearing on a mounting with a retaining ring which has a central hole for the bit and a doughnut.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Jig is almost finished. Bearing distance need to be tweaked to fit most guitars. Zero bar is adjustable, to allow you to use different sized straight cut bit or end mills instead of being stick on one type. I'm in the process of modifying a 26mm insert end mill (just need to turn the shaft down to 6mm) for this so I can use the right diameter of bit. The insert end mill just takes standard APKT1605 inserts.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Look forward to seeing this completed and in use. Keep us up to date.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Almost ready to use. Zero bar hasn't been added because it's really not necessary... but I need to wait until monday for stores to open so I can get some hardware. I also need to make a donut.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Looking good.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

For those interested in a LuthierTool setup, I saw a used one on eBay. It has the jig, tower and cradle for a good price compared to the price of a new full setup. As I said above, I like the jig and can take or leave the tower and cradle, but this would be a low-work alternative.

Can you link it? I was looking and I see a couple, but can't tell if they were used. I never use the cradle ones because they require expensive set of router bits...

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Technically the jig is ready to use, but still need to make and fit a donut onto the jig. I added the end mill that has been modified to fit the router but the router vibrates very strongly and so I was wondering if it's possible for me to have the bit balanced so that it wouldn't vibrate so much? As you can see the bit takes two APKT1106 inserts. I use aluminum cutting insert as they are optimized for cutting soft materials such as aluminum or wood. Steel inserts could work but it would not be as sharp as aluminum. I have to reduce the speed of the router for the thing to not shake apart during use but even at the reduced speed it cuts hard wood like knife through butter.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com