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I'm pretty confident that this question is a non-issue but I'll ask anyway to be sure. I'm considering buying the Stew-Mac tru channel binding jig however when I look at the pictures they post of it, the actual ledge on the donut that will rest on the guitar top (or back) seems pretty thin. I know this is the idea but it has me wondering if it could drop into the purfling ledge while cutting the binding ledge (if the purfling ledge was cut first). What I suppose is that there is enough clearance from the cutter to the donut so that the donut ledge must sit back far enough on the guitar surface but, again, I just want to be sure prior to ordering. Can anyone please confirm this for me?
Thanks,
Pat

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Good question Pat

I'm an inexperienced luthier but I have had the exact problems you're worried about when using the Stewmac binding jig.

You have to cut the purfling channel first or the bearing for the cutter may run inside the binding channel. On a recent guitar top I cut the purfling channel quite wide to accomodate an abalone edge. Then, when I cut the binding channel the donut slipped into the pufling channel

I'm making another guitar now and I'm really worried about using the jig. The Donut really does seem to be too small. I can't believe that Stewmac haven't realised this so I'm thinking maybe I'm doing something wrong

Anyway, i'm sure someone else here will be able to chip in but as far as I'm concerned you did right to flag this up.

Mat

Thanks for the heads-up Mat. Anyone else with the same experience?
Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

I'd give them a call but if it does fall into the channel then just adjust the depth for the binding. The bottom of the purfling channel should be flat shouldn't it. Sure looks flimsy to me. Cheaper to build one from wood and a drawer slide I think.

Cheaper still to make Dan Fobert's binding router arm found on the L.I.N.T. site

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I use this jig and it is great. Very simple to use and produces great results. There is a little collar that comes with the cutter that moves the bearing further away from the cutter when doing purfling so it does not fall into the channel as you are saying.
The body carrier is bit fiddly to set up and would be better with adjuster knobs you can access from the top.

With a slippery surface for the carrier to ride on it is very easy to control and I set the depth knob just under the binding channel so if the router slips off the guitar it only falls about 5mm.
Dominic

I got the Stew-Mac binding jig set up for our guitarmaking class, and can offer the following -

-- Use the Stew-Mac carrier base as a template to make one out of melamine. Use melamine for the base that the carrier rides on and the carrier will glide easily under the laminate trimmer bit.

-- To rout the binding channel first - which makes more sense to me because you hog out most of the mass for the purfling channel before cutting the small purfling channel on final pass - I use the LMI binding router bits. The pilot bearing rides lower; there are more bearing choices; and, unlike Stew-Mac which builds .012" allowance for expansion into its bit sizes, uses actual depth of cut for its bearing sizes. More expensive, but worth it.

-- Like many other OLFers, I like the Bosch Colt laminate trimmer in this jig: light weight, soft start and variable speed. It has been worth the effort to tap a couple of screw holes to get the Colt to fit the Stew-Mac jig.

-- I like the fact that the jig takes down and stores in practically no space at all, just a couple of pieces of flat melamine. With a little ingenuity, all the Stew-Mac hardware fits in the Colt carrying case.

Just my opinion, but it works for me.

Larry

OK: I called Stew-Mac and confirmed that, when using their binding router set you must cut the binding ledge first then install the collar so the bearing runs on the side while you then cut the purfling ledge.

Larry (or anyone else that has similar experience), can you tell me more about using the Tru Channel with the LMI binding router set? In particular, how does the cutter fit through the doughnut? I ask this because the Stew-Mac cutter is .925" in diameter whereas the LMI cutter bit is 1" in diameter. When I asked Stew-Mac about this all they could tell me was that the doughnut hole diameter was exactly 1" so I may have to do some shaving to get the LMI cutter to fit. I have the LMI set but this is something I hadn't thought of until I saw your post.

Thanks,
Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

After giving it some more thought and reading all the back threads where the general consensus seems to be that the William's is the best binding jig, I've decided to build Dan Fobert's router arm. I wonder though, why do people go through the trouble of building carriages? Why not just use your external form clamped to a table to hold the guitar steady and true while doing the routing?

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Depending on the mold of course one might not have enough guitar sticking out for the bearings to clear the mold. But that's a pretty good idea Pat. Just make sure the body is proud enough of the face of the mold for the bearings to clear and it should work out fine. Also maybe leave the spreaders in the guitar to make sure it doesn't move on you.

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