Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to about
2mm easily. The workpiece warms up (actually, quite hot) and it seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or slow?
Ta.

"Grumps" wrote in message
...
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to
about 2mm easily. The workpiece warms up (actually, quite hot) and it
seems that drilling stops.
Is there a technique for drilling this type of material? High rpm or slow?
Ta.

SLOW! I'd use a hand drill.

Grumps wrote:
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to about
2mm easily. The workpiece warms up (actually, quite hot) and it seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or slow?


I suspect your drill is simply getting clogged and so is unable to cut
any further in. The trick with soft materials, especially something like
lead, is a very slow drill speed, and I mean really slow. Drill a little
way in, and lift up to allow swarf removal. Repeat a few times until
you're at the required depth.


--
Grunff
http://www.greendoug.com - a forum for all things environmental

"Grumps" wrote in message
...
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm
in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get
to about
2mm easily. The workpiece warms up (actually, quite hot) and it
seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or
slow?
Ta.



I expect that the flutes of the drill are getting clogged with the
relatively soft swarf. Use a 'pecking' action - drill in a short way,
withdraw to clear the drill flutes then start again. The smaller the
drill the faster you need it to turn. See here for a chart:

http://shopswarf.orcon.net.nz/drillspeed.html

AWEM

"Andrew Mawson" wrote in message
news

"Grumps" wrote in message
...
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm
in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get
to about
2mm easily. The workpiece warms up (actually, quite hot) and it
seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or
slow?
Ta.



I expect that the flutes of the drill are getting clogged with the
relatively soft swarf. Use a 'pecking' action - drill in a short way,
withdraw to clear the drill flutes then start again. The smaller the
drill the faster you need it to turn. See here for a chart:

http://shopswarf.orcon.net.nz/drillspeed.html

Thanks all for your replies.
And thanks for the link to that chart.

The message
from Grunff contains these words:

I suspect your drill is simply getting clogged and so is unable to cut
any further in. The trick with soft materials, especially something like
lead, is a very slow drill speed, and I mean really slow. Drill a little
way in, and lift up to allow swarf removal. Repeat a few times until
you're at the required depth.

And experiment with the angle of the cutting edge of the drill. Too
sharp may cause problems if it's trying to remove too much material at a
time.

--
Skipweasel
Pay no attention to that man behind the curtain.

Grumps wrote:
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to about
2mm easily. The workpiece warms up (actually, quite hot) and it seems that
drilling stops.

If dimensions are not critical, I'd start by trying a hammer and nail.

"Grumps" wrote in message
...
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to
about 2mm easily. The workpiece warms up (actually, quite hot) and it
seems that drilling stops.
Is there a technique for drilling this type of material? High rpm or slow?

You should find that quick spiral drills work better than ordinary jobber
drills.

Colin Bignell

Grumps wrote:
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in very
soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to about
2mm easily. The workpiece warms up (actually, quite hot) and it seems that
drilling stops.
Is there a technique for drilling this type of material? High rpm or slow?
Ta.


pull the drill and swarf out and try again.

The soft swarf clogs it,.

Lubrication and a low drill speed works best.

"The Natural Philosopher" wrote in message
...
Grumps wrote:
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm in
very soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get to
about 2mm easily. The workpiece warms up (actually, quite hot) and it
seems that drilling stops.
Is there a technique for drilling this type of material? High rpm or
slow?
Ta.


pull the drill and swarf out and try again.

The soft swarf clogs it,.

Lubrication and a low drill speed works best.

From my apprentice days I seem to recall that Turpentine was the recommended
lubricant for lead. Paraffin would also probably work - I always used that
for machining aluminium.


--


--
John

John wrote:
"The Natural Philosopher" wrote in message
...
Grumps wrote:
Hi
I need to drill 1.5 - 2.0mm diameter holes to a depth of about 8mm
in very soft alloys / lead.
Using a small model maker's drill of unknown rpm only seems to get
to about 2mm easily. The workpiece warms up (actually, quite hot)
and it seems that drilling stops.
Is there a technique for drilling this type of material? High rpm or
slow?
Ta.


pull the drill and swarf out and try again.

The soft swarf clogs it,.

Lubrication and a low drill speed works best.

From my apprentice days I seem to recall that Turpentine was the
recommended lubricant for lead. Paraffin would also probably work - I
always used that for machining aluminium.

Thanks.
What do you call low speed (in rpm) for a 2mm bit?

Grumps wrote:

What do you call low speed (in rpm) for a 2mm bit?


Hand drill speed - 100-300rpm tops.


--
Grunff
http://www.greendoug.com - a forum for all things environmental