purpose of "waist"? (photo)

He

http://user.it.uu.se/~embe8573/drill-letter/drill.jpg

we see some familiar/interesting material.

From left to right, I think it is:

(1) a PZ2 "bit" for a bits screwdriver;

(2) a magnetic bits holder for a
drill & driver;

(3-4) two pieces for the D&D, of which the
first is a T20;

(5-6) an 8 mm socket and a "bits to socket"
adaptor; with

(7) an 8 mm socket with the bits 5/16 end
part, so no adaptor is needed; and

(8) a roof screw.

Question is, on items 2-4, there is the "female
waist" - what is the reason for this, and is
there a disadvantage without it, as with items
6 and 7?

--
underground experts united .... http://user.it.uu.se/~embe8573
Emacs Gnus Blogomatic ......... http://user.it.uu.se/~embe8573/blogomatic
- so far: 26 Blogomatic articles -

On 1/2/2017 7:42 PM, Emanuel Berg wrote:
He

http://user.it.uu.se/~embe8573/drill-letter/drill.jpg

we see some familiar/interesting material.

From left to right, I think it is:

(1) a PZ2 "bit" for a bits screwdriver;

(2) a magnetic bits holder for a
drill & driver;

(3-4) two pieces for the D&D, of which the
first is a T20;

(5-6) an 8 mm socket and a "bits to socket"
adaptor; with

(7) an 8 mm socket with the bits 5/16 end
part, so no adaptor is needed; and

(8) a roof screw.

Question is, on items 2-4, there is the "female
waist" - what is the reason for this, and is
there a disadvantage without it, as with items
6 and 7?

I have always assumed that there was some kind of retention system that
used it, tho I've never had anything that did.

It could also serve another purpose as a tooling index mark, used to
hold the part precisely during manufacturing. If you want to do
machining on both ends at once, you need some way to clamp the thing in
the center, and there needs to be a way to exactly fix its position on
the center axis.

The far-left short Phillips screwdriver bit has little "nicks" set
forward in the hex-end edges, which might be the same thing.

https://www.google.com/search?q=scre...SD5xw0NmslM%3A

the machine tooling bits may 'take a breather' at the 'waist' realigning axis to the bit head.

I use long bits. there's a choice of chucking the near head hexagonal or the hex above waist.

I haven't noticed a diff tween long n short but assume there is more twist at the top end.

I use bits for wood n plywood, not metal

favorite for wood device construction

https://www.google.com/search?site=i...k1.QSlkTgJsqU0

http://www.ebay.com/itm/Impact-Drill...-/111905188619


Optimized Shock Zone geometry absorbs peak torque and prevents breaking

DougC wrote:
:
: (2) a magnetic bits holder for a
: drill & driver;
:
: (3-4) two pieces for the D&D, of which the
: first is a T20;
:
:
: Question is, on items 2-4, there is the "female
: waist" - what is the reason for this, and is
: there a disadvantage without it, as with items
: 6 and 7?
:
:I have always assumed that there was some kind of retention system that
:used it, tho I've never had anything that did.

It's ubiqutious on power impact drivers, where these sorts of bits are
usually used. They have a spring loaded chuck, which lets you push
the bit or bit holder in place, and then retains it until you pull the
chuck (I guess it's really a collet?) collar foward, which withdraws
the retaining pins, and lets you remove the bit.

--
sig 94

https://goo.gl/0iqtew

I use a porter cable cordless drill with Chuck clutch. The chuck n battery is a completely different tool n tool experience than a B&D type drill.

https://www.google.com/search?client...iw=360&bih=560

Moments when I stop drilling n am 'taken aback' by the ease of this.

On Tue, 03 Jan 2017 02:42:42 +0100, Emanuel Berg
wrote:

He

http://user.it.uu.se/~embe8573/drill-letter/drill.jpg

we see some familiar/interesting material.

From left to right, I think it is:

(1) a PZ2 "bit" for a bits screwdriver;

(2) a magnetic bits holder for a
drill & driver;

(3-4) two pieces for the D&D, of which the
first is a T20;

(5-6) an 8 mm socket and a "bits to socket"
adaptor; with

(7) an 8 mm socket with the bits 5/16 end
part, so no adaptor is needed; and

(8) a roof screw.

Question is, on items 2-4, there is the "female
waist" - what is the reason for this, and is
there a disadvantage without it, as with items
6 and 7?

Officially, it's called a "power groove".
http://www.ereplacementparts.com/blog/wp-content/uploads/2010/03/PowerBitDiagram.jpg
It's commonly used on pneumatic drivers, which are usually hung from a
spring loaded spool, with the tip pointing downward. The drive has a
locking ball that fits in the power groove to keep the tip from
falling out.

You'll also find locking chucks on some power tools:
http://toolguyd.com/blog/wp-content/uploads/2013/04/Milwaukee-M12-Fuel-Impact-Driver-Quick-Release-Bit-Holder.jpg
Since the ball is inside the chuck, I couldn't find a decent photo
showing the locking mechanism and how it works.

Some of the tips are also rather heavy and might be too much for a
magnet:
http://cdn.shopify.com/s/files/1/0158/9580/products/5pc_CntrSnk_grande.jpg?v=1337978620
Using a magnet for retention is a bad idea in some parts of the
electronics industry, so a mechanical lock is preferred.

Mo
https://www.google.com/search?tbm=isch&q=driver+bit+power+groove

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

AE6KS

bits in this image are designed for a ball lock chuck and not a normal no ball chuck as a torque relief design

http://www.homedepot.com/catalog/pro...a54c3_1000.jpg

what is this ball lock chuck named ? gotta link or image ?

is the indent a universal fit for an extension ? a link ?

curious not combative.

On Tue, 3 Jan 2017 17:06:08 -0800 (PST), DATAKOLL MARINE RESEARCH
wrote:

AE6KS

I am not a number.

bits in this image are designed for a ball lock chuck and
not a normal no ball chuck as a torque relief design

It's not a "ball lock chuck". This is what a real ball lock chuck
looks like:
https://www.google.com/search?q=ball+lock+chuck&tbm=isch

http://www.homedepot.com/catalog/pro...a54c3_1000.jpg
DeWalt (owned by Black and Decker) makes some of the strangest looking
driver bits I've ever seen. I suppose that they have a reason to make
it weaker by undercutting and minimizing the amount of metal used, but
I can't figure out why.
http://toolguyd.com/blog/wp-content/uploads/2013/11/Dewalt-FlexTorq-Impact-Power-Screwdriver-Bit.jpg

what is this ball lock chuck named ? gotta link or image ?

I think we're both thinking of a female air hose fitting, which used
balls to lock the mating male fitting. (This is one case where the
female has the balls):
https://i.stack.imgur.com/QDCNP.png
The idea is much the same as the driver bits.

is the indent a universal fit for an extension ?

Not just for an extension. It's for retaining the driver bit via some
kind of snap fit mechanism.

a link ?

I did a patent search but didn't find a mating chuck. Maybe tomorrow
I'll try again.

curious not combative.

Bored not comatose yet.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558