On 19/08/2018 15:06, John Rumm wrote:
On 19/08/2018 11:13, T i m wrote:
On Sun, 19 Aug 2018 03:51:34 +0100, John Rumm
wrote:

On 18/08/2018 21:36, T i m wrote:
Hi All,

I was nearly tempted to get one of the impact screwdrivers as
mentioned here a while back but I couldn't really see a need and
wasn't sure how / when I would use it?

Every time you stick a screw in basically. (also leaves you drill free
to have a drill in it without continuous bit swapping)

I have more than one drill. ;-)

It also looked like it was a hex drive and so limiting what sort of
things you could drive with it (compared with a chuck)?

Yup, although if you really want drill bits with hex shank you can get
them.

I have, admittedly mostly cheap ones ... you know, where the drill bit
turns in the hex under any real load ... ;-(

Yup, I know the kind of thing ;-)


At the market yesterday I picked up a set of hex drive to square drive
adaptors (1/4, 3/8 and 1/2") with the thought of using them in my
Stanley Fat Max cordless impact drill (on speed one) as a form of
electric nut runner (mainly for removing machine screws / nuts) and I
wondered what the RW difference would be between that and the impact
driver?

Max torque on the drill will be significantly lower.

Always John?

Pretty much if you compare like with like...

I mean my 18V combi drill has more torque than my tiny 7.2V ID
screwdriver, but that's not really an appropriate comparison.

Many 18V drills top
out at about 60Nm, and 18V ID will do north of 150Nm

I appreciate you said 'many' but I would have to say my Fat Max
probably deals out as much torque as I can handle (or it feels like it
when I've disabled the clutch and a 1/2" bit snags in something)?

That is one of the areas where an ID is much better - because the torque
is delivered in short impulses, you get far less reaction at the
drill... much of it is dissipated accelerating the inertia of the tool
body, rather than twisting your wrist. That is why its much easier to
use an ID at arms length than a drill - you don't need to get your
weight behind it in the same way.


(although for
comparison a full on cordless impact wrench will usually do several
times that).

Ok.

Also the rotational impact action can be better at freeing
stuck fastenings than continuous torque.

Understood.

I wonder if I was conflating an electric screwdriver with an electric
impact wrench / rattle gun?

Possibly...

"Electric screwdriver" can include anything from the 2.8V B&D
screwdriver up really - at the low end they turn and can spin screws in
and out but usually lack the oomph to do the final tightening. You move
on up through drill/drivers of varies sizes to some that have fairly
significant torque.

The hand held ID:

http://wiki.diyfaq.org.uk/index.php/Impact_driver

Is a different device altogether - and is like a smaller electric
derivation of a pneumatic impact wrench.

I have a 12V rattle gun that is less of a rattle and more of a
clunk-clunk-clunk and I think the only time I used it (a tight wheel
nut) it didn't do any more than I could with the spider brace.

You can get significant toque on a manual brace etc - although somewhat
more physical effort. I would have thought that a 12V ID is probably a
bit small for wheel nuts... although they are popular with scaffolders.

The only time I might use an electric drill / driver on any fastener
is when doing loads when speed is more important that finish or
tightening torque, like assembling a wooden shed. Eg, On anything
'important' I much prefer the feel and control of a manual screwdriver
(or spanner etc).

Do you use an electric driver on your furniture builds OOI John?

I use powered screw driving for *everything* unless I am forced to do it
some other way! These days I will reach for one of my IDs in preference
to a normal drill/driver in most of those cases.

I have a small 10.8V Makita ID that I use more on furniture and lighter
fixings (although it will happily drive a 2.5" 12 gauge screw into a
wall plug if you want it to). Mainly because its very small and light.
Easy to get into tight places and reach screws that would be difficult
by hand (inside cabinets etc).

Bought my lad a pair of these when he was supplementing his income by
helping a builder friend. He reckoned the drill driver wasn't far off my
18v NiCad for "oomph".


When building stuff, then my 18V ID is my preference since it will lob
in 2" twinthread screws without a pilot, with next to zero effort or
fatigue on me.

I'm still amazed how well my old Mak ID is working with 14.4 NiCads.
I've replaced a couple of the packs with unbranded third party clones
and the performance and life is indistinguishable from genuine.




Cheers, T i m