"NT" wrote in message
...
additions welcome, I've not taken an sds one apart yet.


NT



==Chuck types==
Keyless: Quick & easy to use, but bits have a habit of coming loose,
especially with hammer use.

Keyed chuck: these give the best grip, but are less convenient to use
than keyless. Loss of the key wastes time if not attached to the mains
lead.

SDS, SDS+: 2 slightly different names for the exact same thing.
Various performance advantages over the older types of chuck.

SDS max: larger heavier duty version of SDS+


==Non-SDS chucks==

===Keys===
There are different key sizes.

The key can be attached to the mains lead with a cable tie to avoid
wasting time.


===Replacement===
Replacing a chuck is a fairly easy job, and doesn't cost much.
* Ensure the replacement is the right size of thread, and takes a
suitable maximum size of tools.
* Some chucks are unsuitable for hammer use, and some hammerable
chucks are unsuitable for SDS use, which applies much greater forces.


===Removal===
# Open the chuck jaws wide.
# Unscrew the [[screw]] down the centre between the jaws. These often
have a reverse thread and can be very tight. A manual [[impact
driver]] can be useful.
# Insert chuck key, or attach locking pliers to the top of a keyless
chuck
# Tap the key with a [[hammer]] to unscrew the chuck from the drill


===Repair===
Whether the chuck is sticking, loosening unwantedly or the teeth are
out of position, the repair procedure is much the same. Remove the
chuck from the drill, remove its outer cover, and clean the parts up.

Application of [[oil]] where not appropriate can result in chucks
coming undone when they shouldn't.

In some cases its possible to reassemble a broken key ring and have
the chuck then work fine long term. I did this once, and have had no
problem with it. The broken parts are kept in place by the outer
cover, and it works perfectly.


==Disassembly==
# Remove chuck from the drill,
# Clamp the outer body of the chuck near the drill-ward end (don't
clamp near the key tightening ring), ideally in a vice in 2 indented
bits of wood.
# Tap the stem towards where the drill bit tip would be, to push the
chuck assembly out from the outer cover

The mechanism is simple, and self assembly is fairly self evident.



Sorry NT, but my experience is that keyed chucks are rubbish compared with
modern keyless ones. Perhaps on some big precision items like lathes, they
may come into their own, but for the typical diy drill, the day they brought
out the keyless was a huge step forward.

There are keyless and keyless though. Some are very crudely made out of
soft aluminium, and some don't seem to have much of an interlock and do work
loose under hammer, but others have a sort of ratcheting 'clickstop' action,
which in my view is extremely impressive and knocks spots off any keyed
chuck I've used.

S