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After purchasing my binding router tower, i thought i would watch some videos on using it. I was surprised to watch someone who, in my mind, is a professional and should know what he's talking about.

Now, to me, the whole purpose is to get the router bit square to the sides, and for that, i set my guitar with a square. This luthier who will remain anonymous measured the height at 4 points. I believe I've seen this elsewhere as well.

I suppose this might get you close, but i don't think it's what we should be looking at. Am I wrong?

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Hutch

Get the heck off the couch and go build a guitar!!!!

I wouldn't say you were wrong, but it's what works for you. I also measure at 4 points on my shop-built cradle, and it works fine for me. My cradle doesn't allow for using a square so easily.
There are quite a few that use a handheld router, and that seems to work for them.

I suppose you couldn't tell the difference when all is said and done, but the whole purpose is to get the binding ledge perfectly square to the sides like the Elevate jig does. I would have preferred that jig, but it's a little too pricey for me.

Even the dremel attachment is designed with getting the ledge square to the sides.

My cradle doesn'treally allow for checking for square, either. I plan on redu ing the size of it so i can get my square up to the sides.

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Hutch

Get the heck off the couch and go build a guitar!!!!

If the mounting plate and track for the router is leveled with the surface being referenced by the carriage, that would seem to produce a square top cut provided the neck block and tail block measure the same and the bass-side and treble-side show the same measurement from top to carriage base. We had both tower and Fleishman-style articulated arm binding cutters in the shop, and the usual procedure was to level the router plate and donut to the work surface, then use the instrument top as the reference to set the body level in the carriage reference the work surface. Provided the carriage base is flat and true, measurement up from that base should square it to cutter.

If the router base and work surface are actually leveled with a spirit or electronic level, that level can be used to set the body in the carriage as well, but very few surfaces in the average workshop are dead level. We happened to have one due to non-instrument projects, but it seems like just squaring the jig to the work surface is quicker and less fraught with potential for downstream issues related to shifting work surfaces, etc.

As both jigs use the top or back to provide a depth of cut reference, the additional issue of variation in cut depth particularly on the upper bout of the back re: the donut/shoe vs. cutter geometry easy enough to clean up post-cut.

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To add to my earlier post, my router remains square to the table and slides up and down vertically on drawer runners which cost around £8 (British Pounds) plus any scrap wood I had lying around. I've used it to bind and flush trim several instruments including guitars, ukuleles and an octave mandolin, and it's never let me down. When it comes to measuring for squareness, I measure each corner point from the base to the edge of the guitar top, and look for equal distances. The same applies whether routing the top or back. Either way, the idea is to keep the top parallel to the base. Doing it this way, the back will take care of itself.
I'm not saying it's 100% accurate, but certainly good enough to cut the channels. Be careful not to overthink this.

I use a tower setup and a cradle and measure height from the bench top at four points using the top as the reference. I learned this from a professional (now retired) builder and it works. I don't get gaps in my bindings and they are always uniform thickness all the way around the body. So the proof is in the pudding, as they say. If it works, it works.

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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

I do the same as Jay. One thing that has helped with consistency cutting the channels is something I ripped off of Ed, which is a custom donut that is very close to the blade and slightly steeper angle for the donut itself. Works really well.

Edit to add, it’s not really a donut but more of a ramp I guess.



Brad


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Next time you level your guitar, check if the sides are actually parallel to your sides and tower. If not, I think you're all defeating the purpose of the jig. The back has quite a taper and is not at all square at the neck joint. The top is probably square using you 4 measurements. I'm sure it's only minor in the end, because you all end up with nice binding installations but you may as guide the router by hand.

This seems perfectly logical to me but hey, I've built one guitar.

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Hutch

Get the heck off the couch and go build a guitar!!!!

It doesn't matter that the back has that taper. If the rims, head block, and tail block are perpendicular to the top as they should be, and you always do the four measurements to the top (not the back), then the router bit will automatically be parallel to the sides. This is true for both orientations of the body in the cradle.

To be clear about how the four measurements are done, if I'm going to rout the back binding channels, I put the body in the cradle top down and make four measurements from the bench top to the top of the body to get it level and then rout the back binding channels. To then rout the top binding channels, I flip the body over in the cradle and take four new measurements to the top of the body to relevel the top to account for the taper of the back.

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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

There’s no reason that shouldn’t work.

What I did was to take a square and used a marker to draw a line on the back of the bench. Then I adjust the guitar in the cradle using the marker line as a visual guide. First get the neck and tail lock aligned, then the lower bouts.

What Jay says.

maybe I'm missing a point, but it seem to me that as opposed to level a person should be looking for plumb.

what to look for in a spirit level: size of bubble is exactly the size of the hash marks (stabila is a complete joke and I really wonder why they are held is such high esteem), level reads the same when flipped around.

I always used a square. Also made an angled donut on the lathe. Works fine. I suppose measuring could work too I just haven’t tried it that way. Recently I got an Elevate jig and that works fine too.

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Steve Smith
"Music is what feelings sound like"

the key is sides perpendicular to the table so you cut parallel to the sides. If you do the back and make it flat the sides will not be square to the cut , you will find this out real soon when you put the binding on and when you sand flat they looked pinched off

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

As I pointed out above, if you "do the four measurements to the top (not the back), then the router bit will automatically be parallel to the sides." In other words, if you level the top relative to the workbench, the sides will automatically be plumb to the top of the workbench.

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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

I did the a combination of measuring and using a square. But to be honest, with the three recent 00-12 cutaways, it’s been a trade off. Adjusting one end, or side, has an effect somewhere else. Clearly sides weren’t completely coplanar. In the end I gave it my best shot. Just proof in human hands, at least mine, perfection is a lofty goal.