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The guitar is in the finish process now, but I'd like to correct this issue before the next guitar. Using a Williams jig built by Don himself (purchased through Lance during the swap) and an LMI cutter set, I wound up with uneven binding channels. The sides were leveled prior to the process. Do any of you have any tips on making sure everything comes out even? The channels were significantly uneven around the guitar with some areas leaving the bindings either .020" proud or .020" too deep. I don't see how this could be anything but user error on my part.

I dont know anything about the wiliams jig, I built my own out of and old photo enlarger, I had the same problem the first time I ran it, the problem seemed to be the size of my homemade base , being too large, it rode up on the top where the waist is constricted. I shaved off all I could and it works much better now. Jody

James, I've had similar experiences, usually not deep enough so I now use a gramil to mark the channel, before using the jig and then follow up with some chisel work to finish up.

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A higher purpose for wood.
Rich Smith
Issaquah, WA

James, are you being careful to get the sides parallel to the router bit? The guitar needs to be supported to ensure that the sides are parallel. It's also possible that the box construction has allowed too much variation in the angle of the sides.

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David White, Toronto

"All my favourite singers can't sing."

Surely James leveled the guitar. That part is talked about so much around here. James, did you make your own do-nut? Is it the same height all around? Then, what kind of router are you using (how old is it?)

You want the do-nut tall enough so that the metal plate never touches the wood. But too tall, and you have trouble setting depth.

And, is your holding fixture "staying put?" No rocking of the body...

Once I have my body in that fixture, I use blue tape all around it to insure nothing can move.

I am not a big fan of the "holders" and one day I will show you my ideas for improving them.

Mike

Many thanks for the input, everyone. I'm sorry I haven't responded -- we've been busy getting the house ready for Easter guests.

The body was level, but I wouldn't be surprised if it was rocking around a bit even if I thought it was solid. The donut came with the jig, and the section that touches the top is about 3/16" by eye. Todd, what is the advantage of your style?

Mike, it's a PC 310 with only a fair share of use since buying it a year and a half ago. I'd love to see your idea for improving the cradle.

Are we saying here that even if I get as close to perfect of a cut as I can that there will still be areas that are either proud or shallow? I hope not.

Todd is right. I think you have a "rocking" problem also. It will not take much to cause the problem. All four pads must solidly touch the bottom side. Try taping also.

Mike

I have the donuts if you need one. I make them of UHMW nylon. As Todd and others point out , to make this work you have to look at the points of contact. The less points of contact you have the more accurate you will get.
The donut in theory uses 2 points , one leading and one trailing. The farther in the back or top you locate the less accuracy you loose.
john hall

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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

I had a few messages and I sent replies. If you didn't get one please use my email tippie@epix.net
thanks

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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

I don't have a Williams machine but if your table isn't level wouldn't that also effect the angle of the cutter. And the same for any sagging of the arm as it extends out ward as it would make the router not square to the top. And is the reason the channel depth changes from the waist to neck on the back because it is cutting on a diagonal due to the taper from waist to neck. Would this difference be less with a 1/4" bit as opposed to an 1" bit. Although you need an edge bearing with the 1/4" spiral downcut bit. The reason I ask this is because I haven't ever use the 1" bit and bearing kit just a edge bearing and 1/4" bit and my problem isn't with the depth or heigth of the channel so much as with the constant depth of the thickness(.060, .070, etc.) due to the edge bearing and the tangent of cut issue. I guess I'm asking also if the jig's vertical movement is square to the table also. I would think if everything isn't true and square that with the Williams style and the arm extending out and around the work that would magnify the issues. And then if the cradle is out or even worst rocking on a not flat surface then , well you probably get the idea what I'm thinking. But like I said I don't have the Williams jig so maybe that's not so much a issue as I might think. And then again maybe an issue to consider when deciding on a binding machine style too.

I hope the messages weren't negative, John. One of your cradles is on my summer stipend list

I think we can call this problem solved. I jerry rigged the body in a radiused dish and ran a level across the top. The guitar doesn't look terrible, and I'm considering it a learning opportunity.

Chris, point about making sure the jig itself is level reminds me that the router itself has a pivot point. How do you guys make sure that things stay level there?

Jim, are you saying you don't have a cradle??? It's also not weather the top is level as are the sides square to the table and router base.

Ladies & Gents, problem solved! James, build the "cradle" yourself. It is the easiest part and I will gladly assist you (PM me).

Without it, you simply cannot maintain a fixed, parallel surface to the router. Although, your dish ideas is not so bad, really. Makes sense. But still, you need lateral support as well, and you need to get the body higher than the dish might allow. But then again, this has got me thinking...

Mike

James, this discussion could help you build a cradle of you own.
viewtopic.php?f=10101&t=21131

Chris, what did you use for padding? It looks like seriously thick felt blocks.

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Aoibeann

That's leather, I won a box of leather pieces at a MIMF anniversity raffle two years ago and it had that soft gray leather in it.

I used cork on mine. I don't think it matters as long as it protects the body and provides some solid support.

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Steve Smith
"Music is what feelings sound like"

What Steve said.

Great, thanks.

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Aoibeann

Again to everybody, thanks a ton.