On 27/07/2020 09:56, alan_m wrote:
On 26/07/2020 17:36, Dave Liquorice wrote:
On Sun, 26 Jul 2020 08:15:14 -0700 (PDT),
wrote:

My SDS (Lucky Screwfix Hedgehog) has started making a loud chattering
noise, there seems to be a lot of play on the bits sliding in and out
of the SDS chuck, and it's not chiselling as effectively as it did.

My green Bosch rattles a bit if there is little or no pressure on the
bit and the action is not very effecctive. Comes a point as you
increase pressure that it suddenly "tightens up" and works as it
should.

All sds drills work that way. The action doesn't really start working
until there is slight pressure on the bit. The drill mechanism hits the
bit forward and you pushing the bit into the work piece pushes the bit
backwards to be hit again by the drill mechanism. If not drilling into
anything the mechanism pushes the bit as far forward as it can and then
retracts back but nothing is pushing the bit back into the chuck
therefore on the next cycle the mechanism is not hitting the back of the
bit (or is just lightly tapping the fully extended bit).

I've often found situations (like nibbling something away) where a
return spring would be useful. I try to use my hand but an external
clip-on sprinq would better - never thought of it before but it should
be easy to knock-up something suitable.