Before I decided to post this, I did a quick search. See link.

The first picture at that link (and the reason for that discussion page) is actually not a screwdriver. But, why not a variant of it which actually is a screwdriver?

Somewhere else on that page is a picture of a 2-position adjustable shank screwdriver, which seems to me to be totally inadequate, with respect to the possibilities one sees in that first picture.

The second variant involves "shank extension pieces", kind of like the extension pieces you can add for a ratchet wrench. For best extension possibilities, you want a lot of short segments between the handle and the bit-holding end.

I've seen some shank extensions that are actually for electric screw-guns/drivers, but they generally have long lengths, not short lengths. I note that these have hexagonal shanks/connection-points. These are not as strong as the square connection points used for ratchet extension pieces (see any "rounded" Allen wrench for proof).

So, for maximum strength, we probably want Triangular shank-connectors. And for best versatility, we want lots of short shank segments. Meanwhile, for SLIM strength, we want a long solid shank that can be fixed at various positions with respect to the screwdriver handle (a really long shank could extend all the way through the handle), as implied by that first picture at the link.

Finally, the third notion involves removable shanks. You have the screwdriver handle and an assortment of triangular-shaft shanks that fit into it. And, of course, an assortment of bits for the business end. Note that for reduced cost, the business end could also be removable from the shank --leaving your screwdriver kit with one handle, one business end, a lot of bits, and a lot of shanks. And, while we're at it, how about making the HANDLE adjustable, too? It has a short section for when you want a "stubby" screwdriver that fits in tight spots, and it has a "handle extension" for when you need a really firm grip.
-- Vernon, Jun 15 2012

Deburring Tool and other stuff http://www.thegarag...ex.php?topic=1237.0
As mentioned in the main text [Vernon, Jun 15 2012]

We are somewhat puzzled as to why this excellent device does not already exist.

[+]
-- 8th of 7, Jun 15 2012


What my nemesis said. [+]
-- Alterother, Jun 15 2012


Baked. British Gas repair men carry a 1/4" flathead screwdriver and a series of extension shanks reaching a maximum of three feet, in segments of 18", 9" etc which can be combined to make any length. This strange tool is used for adjusting the pressure valves of domestic gas installations which, for reasons of safety, are set into a narrow and deep hole protected by a small cover.
-- MaxwellBuchanan, Jun 15 2012


//in segments of 18", 9" etc which can be combined to make any length//

17 mm? 351 angstroms? 1.9 * 10^14 AU?

Yeah, I didn't think so. So much for /any/ length.
-- ytk, Jun 16 2012


The set goes down to 0.03515625". Adjustments finer than that are performed by precisely warming or cooling the shank.
-- MaxwellBuchanan, Jun 16 2012



random, halfbakery