Official Luthiers Forum!

Been using some of my "lung breather" time to upgrade fixturing. (Don't seem to be allergic to aluminum and UHMW ) I've seen pics of this type here on OLF but can't find the thread. Anyone lead me to it? The last photo looks like the router is drooping--trust me it isn't. The indicator mounting holes are normally used to mount a dust collector shoe on a CNC router.
Construction is 1x2x1/8" wall mounted at 45 degrees and 1x1x1/8" wall for the parallel links with 3/4" CR steel shafts running in UHMW for the pivots. The bracket holding the router is one I had on hand from K2 and a Bosch 1617 EVS router.
The two curved links at the top are to allow the arms to fold back next to each other while clearing the gas cylinder mounting. The black plastic knob is an adjustable stop to hold the cylinder extended for an extreme up (non-working) position. The cylinder balances the full size router and the upper hole could be used for a lighter trim router. I use a bearing collar that runs on top of the guitar body which controls the depth of cut. Another bearing collar below the tri-wing cutter sets the width of cut. The bearings mount to a custom arbor. (I've used this bearing setup for a number of years)
The next step in this project is to make the mounting/clamping blocks to hold the guitar body. Planning to use aluminum t-slot bars attached to the table top to adjust the position of the clamp blocks.
I figure I can always sell this setup to someone if I end up not building any more archtops. I enjoy building fixtures like many of the rest of you guys.

That's a really nice looking router arm Nelson!

_________________
Jim Watts
http://jameswattsguitars.com

I made one similar to that.
Except it's made out of birch ply and elastic bands, with the slack in the joints taken up by wood screws!

_________________
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.

Very Very nice , with a tool like that you have to build more arch-tops. Looks like the trick for routing bindings, right? Might be a market there.

Beautiful job. I think this is the one featured in the thread you recalled.

http://www.luthiertools.co.uk/

I know Arnt and some other members here have one and I got one after reading the thread. I found it easier to use if the router actually sat against the top with some force so I swapped out the shock strut for a lighter one. When it floated, both down and side pressure were required and I never really got used to that.

I actually think the picture may be of Arnt's device. It has springs to counteract the weight of the router but mine came with a shock strut.

It's nice for tight archtop cutaways. Otherwise, and I hate to admit it, I still kind of prefer my old Ribbicke tower for standard flat tops.

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

Very nice!

Thanks for the interest, guys! I wondered about the floating and whether a slight gravity assist would be best. The gas spring came off the topper that was on my '89 chevy S10 pickup. Would no longer hold the back door open. Had to replace it but couldn't stand to toss it.
The binding router setup that I've been using mounts the guitar body on a vertically adjustable turntable with the counterbalanced router on an articulating arm.