George,
I'd love to know more about this design. If Strandberg isn't still making them and is OK with it, I have easy access to CNC machining, and we could make a couple of these. I'd love to give one a try.

Is the caul made of some sort of very firm but somewhat flexible material? I can't figure out what is going on if it isn't.

I've already sketched out some ideas with my industrial design buddies for how an internal mechanism could work to shape the caul, and would ideally want it to go from about 6" to 24".
That said, I don't want to infringe on their idea if its a product they intend to move forward with.

To my knowledge there is NO Patent, pending or otherwise, neither a copyright. There has been ample time for any and all of these to be initiated, but no action taken to date! The Youtube Video he published was on March, 10, 2012! So IMHO, show me, and lets bless a well-deserving bunch of fellow Luthiers! You can't copy something you can not SEE, and that sums up the mechanism, as put forth. Gb bg PS: 6" to 24" would indeed be IDEAL, and don't forget to make it wide enough for WIDE board Basses! And don't forget to send me one, Har! Thanx mate!

I've already sketched out some ideas with my industrial design buddies for how an internal mechanism could work to shape the caul, and would ideally want it to go from about 6" to 24".
That said, I don't want to infringe on their idea if its a product they intend to move forward with.

I’m assuming it is being pulled up/pushed down in the center, and the slot merely gives it room to deform. I picture some arm that pivots with the turning of the screw thereby also supporting the center under pressure.

I’m not an engineer, but I do have access to a large Haas machine. Someone figure it out and I’d be happy to make a handful for the cost of material.

(Rant alert!)
As far as intellectual property, I have a”Fox” bender, several “Dreadnaught”, “L-0”, and “Telecaster” guitars I’ve made, and endless other innovations I’ve incorporated into my work that were dreamt up by others. For all of history we learned craft from copying others. We wouldn’t have evolved from subsistence hunting throwing stones if we didn’t copy innovations and pass them along. This obsession with intellectual property rights is a mystery to me and seems to stifle innovation and reward owners of abstract property rights over people creating actual useful goods. As someone who has worked most of my adult life as an attorney attending to these relatively new property owners, the absurd reverence, sense of superiority, and sanctimony around often modest little innovations reminds me of medieval notions of Devine Right.
(Phew!!! End of rant) It all boils down in this world, to the Right to have Might! I agree totally with your 'Rant'. I would have been very happy for Mr. Strandberg, if he made a Bundle off his clever invention, and I've offered several times to help him toward that end with my humble purchase, but instead, he has done nothing with it, except to use it in the construction of his own wonderfully crafted instruments. Stop, and think what this ONE item would replace? ALL of the std. brass cauls offered by the whole industry!! Puts me to mind of the legendary 200 MPG carburetor, or the H2O Auto engine, neither of which ever saw a "Production" line. I'm waiting now to hear back from Daniel, and his friends about a sketch of their ideas on this Gizmo, and I hope it doesn't receive the aforementioned "Strandberg" strangulation, we'll see, and can only pray, and hope!
(Sorry for the rant)


Sent from my iPhone using Tapatalk Pro

I've already sketched out some ideas with my industrial design buddies for how an internal mechanism could work to shape the caul, and would ideally want it to go from about 6" to 24".
That said, I don't want to infringe on their idea if its a product they intend to move forward with.

To my knowledge there is NO Patent, pending or otherwise, neither a copyright. There has been ample time for any and all of these to be initiated, but no action taken to date! The Youtube Video he published was on March, 10, 2012! So IMHO, show me, and lets bless a well-deserving bunch of fellow Luthiers! You can't copy something you can not SEE, and that sums up the mechanism, as put forth. Gb bg PS: 6" to 24" would indeed be IDEAL, and don't forget to make it wide enough for WIDE board Basses! And don't forget to send me one, Har! Thanx mate!

I wasn't aware that you had completed this 'Clone' of the strandberg caul design, and yes, I'm interested. Gb bg

Sorry, I wasn't following this thread closely enough, didn't mean to leave everyone hanging.

Work got busy, so we hadn't moved beyond some quick lunchtime sketches. But I plan to get back at it. Need to tighten up the drawings, might 3D print a model to test a few elements, and then I can move to machining a prototype.

One consideration is if PEEK thermoplastic polymer is critical for durability/flexibility of the caul itself, as that material is substantially more expensive than any other component in the adjustable caul.

Is the standard 2.5" caul width appropriate for the majority of uses? I never work on 7-string guitars - how wide are those fretboard getting at the body?

Fortunately I have both the 3D printers and a full machine shop available, just need to make time to finalize the drawings.