Re: drilling lead...here's how
Carron,
This is wonderful. I love the addition of correct terminology for
drill bits being "twist drills"
I will give this method a try. Although, working with a 7/64
twist drill (see, I am a quick learner) is akin to "milking a mouse".
I do have an ample supply of WD40 on hand (as well as duct tape) to
accomplish the job.
Thank you for your support. All I need now is a little time to
accomplish the task.
David Jost
Carron wrote:
This is wonderful. I love the addition of correct terminology for
drill bits being "twist drills"
I will give this method a try. Although, working with a 7/64
twist drill (see, I am a quick learner) is akin to "milking a mouse".
I do have an ample supply of WD40 on hand (as well as duct tape) to
accomplish the job.
Thank you for your support. All I need now is a little time to
accomplish the task.
David Jost
Carron wrote:
> *not* drill bits, they are twist *drills*. the thing you have in your hand is
>snip
In a message dated 05/04/2001 8:<BR51:<BR14 AM
Eastern Daylight ,djost@...writes:
your best bet is to decrease the releif on the lip of the drill (these are
*not* drill bits, they are twist *drills*. the thing you have in your hand is
a drill motor, and if you put a screwdriver thingy in the chuck of your drill
motor, then you have a *bit* in there :-) Calling them bits came from the old
days using augers which are bits (brace and bit). When twist drills came
along, folks just applied the term bit incorrectly to the *new thingy* that
they stuck in their brace. Sorry about the pedanticism... 10 years as a
toolmaker, don'cha know :-)...using the terminology won't help make the
drills quit breaking, though.
Have you a bench grinder or a disc sander? Either can be used to decrease the
relief. You'll need a fine stone or sandpaper around 220 grit or finer to
make a good job of it.
Hold the drill with the point upward in good relflected light. rotate it
until you are looking straight down one of the lips (lips are the two
straight cutting edges at the tip). Hold the drill exactly vertical and
notice that the material slopes downward away from the lip. This is the
*relief angle*. Now comes the harder part. You want to decrease that relief
angle from 6 or 7 degrees to 2 or 3 degrees....even 1 is OK, bot ) is not :-)
And, you want to get it the same on both lips, and you want to maintain the
135 degree angle of the point, and you want that angle to be evenly divided
between the two lips, and you want to keep it centered. All this is
especially important with soft metal.
With your grinder or sander turned off, practice the operation "dry" a few
times. Hold the drill normal to the plane of the wheel (side of the wheel if
a grinder) with the lip (which is now turned down, away from your vision)
dead level with the horizon. Now, while keeping it dead level, rotate the
back end of the drill toward you so that the lip becomed parallel with the
wheel. When you think it is parallel, then drop the back end straight down a
couple of degrees... make your hands, brain, and nerves remember just how far
you dropped it.
Now comes the touchy part... you ease the drill into the wheel and hold it
lightly while it sparks *just until the grinder has cut about 1 mm of flat
behind the lip. Quickly move it away from the wheel. Spin the drill in your
fingers until the other lip is level and go through the entire procedure
again.
Now look struaght into the tip of the drill...Are both new shiny flats the
same width? Are the edges of those falts parallel? Is the point centered?
Good. Hold the drill vertically and spin it until you are looking at the
front of one lip and the back of the other. Does the angle look the same on
both sides of the tip? If so, you can now drill your holes without the drill
catching and pulling in.
You have the best chance of getting it right on your very first attempt, but
if something is off, you now know how to fix it.
Other things to note about drilling lead. A more powerful drill motor is
better than a smaller one. It allows the torque to remain high as you "back
off" the pressure; in other words, the drill won't as easily stop and catch
while you are trying to adjust the pressure. Keep that hole absolutely
straight...allowing the drill motor to change angles from vertical while the
hole is going in is a sure way to break a drill. Don't use heavy oil...WD40
is one of the very best drilling fluids for soft metals.
BTW, the antimony makes the *lead* harder, but should make the drilling
easier, as there is *less* tendency to grab.
Best of luck/Carron
Eastern Daylight ,djost@...writes:
> The lead is about 3% antimony which makes it easier to handle butDavid,
> harder to drill.
your best bet is to decrease the releif on the lip of the drill (these are
*not* drill bits, they are twist *drills*. the thing you have in your hand is
a drill motor, and if you put a screwdriver thingy in the chuck of your drill
motor, then you have a *bit* in there :-) Calling them bits came from the old
days using augers which are bits (brace and bit). When twist drills came
along, folks just applied the term bit incorrectly to the *new thingy* that
they stuck in their brace. Sorry about the pedanticism... 10 years as a
toolmaker, don'cha know :-)...using the terminology won't help make the
drills quit breaking, though.
Have you a bench grinder or a disc sander? Either can be used to decrease the
relief. You'll need a fine stone or sandpaper around 220 grit or finer to
make a good job of it.
Hold the drill with the point upward in good relflected light. rotate it
until you are looking straight down one of the lips (lips are the two
straight cutting edges at the tip). Hold the drill exactly vertical and
notice that the material slopes downward away from the lip. This is the
*relief angle*. Now comes the harder part. You want to decrease that relief
angle from 6 or 7 degrees to 2 or 3 degrees....even 1 is OK, bot ) is not :-)
And, you want to get it the same on both lips, and you want to maintain the
135 degree angle of the point, and you want that angle to be evenly divided
between the two lips, and you want to keep it centered. All this is
especially important with soft metal.
With your grinder or sander turned off, practice the operation "dry" a few
times. Hold the drill normal to the plane of the wheel (side of the wheel if
a grinder) with the lip (which is now turned down, away from your vision)
dead level with the horizon. Now, while keeping it dead level, rotate the
back end of the drill toward you so that the lip becomed parallel with the
wheel. When you think it is parallel, then drop the back end straight down a
couple of degrees... make your hands, brain, and nerves remember just how far
you dropped it.
Now comes the touchy part... you ease the drill into the wheel and hold it
lightly while it sparks *just until the grinder has cut about 1 mm of flat
behind the lip. Quickly move it away from the wheel. Spin the drill in your
fingers until the other lip is level and go through the entire procedure
again.
Now look struaght into the tip of the drill...Are both new shiny flats the
same width? Are the edges of those falts parallel? Is the point centered?
Good. Hold the drill vertically and spin it until you are looking at the
front of one lip and the back of the other. Does the angle look the same on
both sides of the tip? If so, you can now drill your holes without the drill
catching and pulling in.
You have the best chance of getting it right on your very first attempt, but
if something is off, you now know how to fix it.
Other things to note about drilling lead. A more powerful drill motor is
better than a smaller one. It allows the torque to remain high as you "back
off" the pressure; in other words, the drill won't as easily stop and catch
while you are trying to adjust the pressure. Keep that hole absolutely
straight...allowing the drill motor to change angles from vertical while the
hole is going in is a sure way to break a drill. Don't use heavy oil...WD40
is one of the very best drilling fluids for soft metals.
BTW, the antimony makes the *lead* harder, but should make the drilling
easier, as there is *less* tendency to grab.
Best of luck/Carron