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I've read alot of posts about binding jigs, and I'm wondering how they help the binding process at all. I've only built one guitar, but it didn't seem to be a problem to just put a bearing and bit on a router and cut away.

What am I missing here?bbeardb38723.4949074074

The problem is keeping the binding parrallel to the sides when the top and especialy the back are not perpendicular to the sides. If your router is sitting right on the top or back, you will notice that the binding ledge cuts deeper at the bottom than it does near the plate when you are cutting in the upper bout area of the back. It sort of depends on how much arch you put in your plates and how much the back falls off towards the neck.

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I would assume the purpose of a binding jig is the same purpose as any jig - to provide a consistent, easily duplicated, method of performing the same task.

One could also just cut 200 pieces of wood 3" long by hand, not a real challenge, but if you set up a jig they will all be 3" in a precise and predictable manner.

Similar approach, I suppose, with a binding jig.

For folks like me a jig is overkill, because the one or two guitars I'll build over the next 5 years wouldn't justify it. For a pro or serious hobbyist? No question in my mind - a jig.

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Repeatability and risk reduction. In another life I did some jig and fixture design for manufacturing. Every time I got a request for one, it was because the task was expected to be too error-prone without fixturing, or some amount of materials had already been destroyed. Safety was a factor too.

Last summer, I built a simple jig for my lam trimmer to cut binding channels on my first guitar, just two bearings that ride against the sides, on a plate that adjusts for channel width, no bearing on the cutter. It went fine, but as I was routing, it occurred to me that in a split second, I could conceivably ruin a month's work along with a sizeable chunk of cash. The right jig would have just about eliminated any risk, but I'm like LarryH, don't build enough to justify an elaborate jig. But for some, it would be money well spent.

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[QUOTE=John How] The problem is keeping the binding parrallel to the sides when the top and especialy the back are not perpendicular to the sides. If your router is sitting right on the top or back, you will notice that the binding ledge cuts deeper at the bottom than it does near the plate when you are cutting in the upper bout area of the back. It sort of depends on how much arch you put in your plates and how much the back falls off towards the neck.[/QUOTE]

Ok, I can see that, but does it really matter if it cuts deeper? As long as your binding is a smidge bigger than your cut, you can just scrape it flush. That would hold whether is is deeper inside the guitar or deeper down the side of the guitar.

Sure you could do that but I like to have it come out with as little scraping and cleaning as possible and to be the same thickness all the way around. The routing jig gives me that. I guess it all depends on how often you expect to be doing that.

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If the tops & back of a guitar were flat & the sides perpendicular to them, you'd have very little trouble using a router with a bearing bit to cut clean binding ledges.
The chief difficulty is holding the router vertical while following a curved surface.
Jigs like the ones John sells, or the Fleishman/Williams type, hold the router on a vertical plane, allowing the operator to concentrate on the ten or twenty other things that can go wrong while routing the channel.
I have used my new Fleishman / Williams jig on four instruments now & its been just great. No more divots, nice even ledges that are clean & square. Without the sweat & ulcers.
I love it!

Perhaps you are right. After I do some more I'm sure I might see the benefit. It's just hard to visualize how things can help or certain processes be easier when you've only done one and only know one building style.

B, like John said, sure you can cut the ledge deeper at the bottom of the channel and scrape and sand to clean it up but than you would be left with several other problems.

First, the binding would not be sitting parallel with the side of the body, if the router were registered off the back of the guitar (assuming the guitar is built with a domed back). The dome of the back essentially is angled approximatly 4* off the perpendicular line to the side. You have now cut a channel which looks like this,



When you glue in your binding, you will have one of two problems, you will either have a gap at the bottom of the channel which you will not want to fill and you don't what to sand or scrape the side to make the binding parallel with the side, or if your binding is thicker than the cut you will have a binding which overhangs the side at the top edge, which will have to be scraped and sanded to become parallel with the side. You can do the second, but there is no garantee that the binding will be a uniform thickness once all the scraping and sanding is done. I know, the first three guitars were done with a lam trimer with the small guide roller attachment and the binding is all varying thickness' all over the guitar and is very noticable in some spots.

So if you cut the channel parallel to the side like this



you have a nice parallel channel to glue the binding into with very minimal scraping and sanding AND the big difference is that the binding SHOULD be a uniform thickness once the job is done.

Without a jig or binding machine, it is very difficult to cut that channel so it is parallel to the side for the entire run of the body. It can be done, but I don't know to many people who can look down the side, have a very steady hand with a tool running at 10,000+ rpm and keep the bearing parallel to the side while keeping the router base from sitting "flat" on the back of the body. It's just very, very tricky and a jig/machine takes alot of the trickyness out of the job.Rod True38723.5905439815

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I was writing and drawing while you posted. I hope this helps clear things up a bit.

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The drawings are wonderful, thanks! I was picturing it in my head, but had no way to share it. I guess my next question would be then, do you cut the channel to the EXACT thickness of the binding, or a little smaller so the binding still has to be scrapped flush. I would assume a little narrow since I doubt the bindings are the exact same thickness their entire length, especially when glue is accounted for. You would still then have the same problem as before when it came to scrapping, wouldn't you?

The base of a router indexes from the top(or back),,,that's no problem if the back or top is flat, but if you build with any arch in either the back or top and you use just a router and bit with bearing, the width of the binding ..after it is installed and scraped flush with the side will not be a consistant thickness around the perimeter of the guitar..particularly noticable at the waist.The binding jig I have allows the router to index off of the rim of the guitar..rather than top or back, and by doing so is not affected by that arch the top or back, and consequently the width is consistant the entire perimeter of the guitar...jack

Hi may i interrupt with a question just to make sure i get it right please?

My question would be:Let' say that i use laminate trimmer with bit and bearing with a binding jig on an arch at the upper bout on the back side, when i get to that point, in order to get the same depth of channel cut all the way around, do i have to lower the bit when i arrive near the upper bout,while keeping my laminate trimmer vertically with the sides?or will i have to shave the binding and purfling there ?

Sorry to interrupt but i thought it would be important for me and other new builders also!

TIA

SergeSerge Poirier38723.8297685185

Serge, your not interupting, just being part of the discussion.

You don't have to change the depth of cut once it is set to the binding height. See, what happens is this, there needs to be a small "platform" which the top or back rides against, this set the depth of cut into the body. Now, your not registering the width of the cut off the top, just the depth of cut. Since the cut needs to be parallel to the side (rib) of the body, the register off the top is a small footprint, just enough to hold the body from being cut to deep.

So again, you don't adjust the depth of cut once you've set it to the binding height.

I will take a bunch more pics tonight to help explain more.

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    I built 14 guitars till I started using the jig. At that point I started selling them. Binding can be as simple as 1 piece of wood to an elaborate 45 style setup with 5 different binding being used.
    As you start you build you are more into the process of learning and getting the thing to play. When you get to the next level you are looking at ways to make your work look better ,at that point the jigs and tools that were too expensive when you started , start looking more affordable.
     Binding as a process is simple but as most of us that have been building a while can attest that binding is perhaps the hardest thing to get right.
    When I go to a guitar show I can see very quickly the amatures from the pros , the binding jumps out at me. Eveness and the way it is tight to the body tells me if the builder is on the right track.
   This is part of the fit and finish we all want to make our guitars look good. My first few guitars took me 8 to 10 hours to get the binding right. I can now do that in 8 to 10 minutes. It makes one of the most diffficult jobs error free for the most part. There are more than one jig on the market but they have the same principal , keeping the bit paralle. I will soon have a 2nd binding jig out on the market.
      Jigs just make the job easier and more accurate.
john hall

If you take a look at the factory friday video here(high band width video), watch as the operator runs the guitar over the machine. I was watching to see if he keeps the top and back of the guitar perpendicular to the centerline of the bit/router and there were several times when he wavered off that mark. To me is was evident that as long as the sides stayed running on the rub block, you could waver off perpendicular to the centerline of the bit/router and not worry about it.

I wish we could add the discusion from my other post on the "new binding jig" to this one or visa versa, cause there are good posts on both.

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"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Sorry Rod and John, had to run for duty! Thanks for the explanations, it sure helps, now, i only wonder which kind of jig i'm gonna build for that, that's gonna help me better on that, i'll either go to the archives or start a new thread about it to see what works best for everyone and why. Rod, yes please post your pics .

Thanks again fellows!

Serge Serge Poirier38724.8229861111