by the way broked centre drills can be converted into nice flat bottom drills by grinding the tip square and putting a bit of relief on the citting edges
Gerry
Leeds UK
From: "born4something" <ajs@...>
Reply-To: 7x12minilathe@...
To: 7x12minilathe@...
Subject: [7x12minilathe] Re: Basic problem?
Date: Mon, 19 Mar 2007 10:19:40 -0000
Hi Ken,
Someone (possibly on this forum) had a neat idea after breaking the
tip of a centre drill. They re-ground the thicker remaining stub to
gouge AROUND the broke small tip. This allowed access to get hold of
the broken piece to reverse it out.
Is that viable in this case? Maybe use the stub of an old (broken)
drill bit. Needs to be stumpy and solid. Butcher's technique but may
save a casting.
John
--- In 7x12minilathe@..., "machinest80"
<machinest80@...> wrote:
--- In 7x12minilathe@..., "Capt Ken Appleby"
<captkenn@> wrote:
Hi,
This might sound a bit basic but it has stumped me! While
drilling
on
my lathe, I have broken two 2mm drills in two separate holes in
a
steam engine alluminium casting. They have both broken off flush
so
there is nothing to get hold of and there is not a lot of space
around them. I have thought of over-drilling the whole lot out
(if I
can) and making a screw-in plug and milling it flush.
Is the casting a write-off - Or is there another way?
All help appreciated
Regards
Ken
Hi,
When drilling aluminium a good cutting fluid is a must, this kind
of
metal welds to the drill bit quick.
_________________________________________________________________
Get Hotmail, News, Sport and Entertainment from MSN on your mobile.
gerry waclawiak