Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott

Use a transfer punch. You can get a set for about $10. I'm assuming you mean
1/2" diameter holes?

--
Ed Huntress
(remove "3" from email address for email reply)
"ATP*" wrote in message
...

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott

Use a transfer punch. You can get a set for about $10. I'm assuming you
mean
1/2" diameter holes?

Or, depending on the configuration, he may be able to just clamp the two
together and drill both at once.

--
Ed Huntress

"ATP*" wrote in message
...
Ed Huntress
(remove "3" from email address for email reply)

Or, depending on the configuration, he may be able to just clamp the two
together and drill both at once.

But that would not require additional tools:-)

Unless he needs to buy clamps or a good vise. d8-)

--
Ed Huntress

Scott wrote:

Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

Define "exact".

The ways I know (absent ATP's transfer punch suggestion):

1. Put a stop on your milling table, but the bar up against it, and
drill with a spotting drill or other variety of short, rigid drills made
for milling machines. Accuracy will depend on the finish of the end of
the bar, the fence, the repeatability of your vice, the rigidity of your
machine and the tendency of the bit to walk. This'll probably be
repeatable to within a few thousandths.

2. Find the end of the bar with an edge finder, do the math, go in just
the right amount and drill. Accuracy will be everything in #1 except
for the finish of the fence, and repeatability of the vice, but will now
include the accuracy of the edge finder on whatever surface you have on
the end of your bar. Unless you have a really crappy end stop and vice
this'll probably have a couple of thou more error than method #1.

3. Since you didn't define "exact", just eyeball it and use a hand
drill. Depending on the accuracy of your eyeball you can expect to be
within 100 to 50 thou, this is more than "exact" enough for a great
number of jobs -- but that's probably not what you meant by "exact".

3a. Clamp the bars together and proceed with 3. The match should be as
close as your ability to drill a straight hole at right angles to the
material.

Disclaimer: I'm a beginner and a hobbyist. Someone who's actually done
this for pay will have an answer that's both faster and more accurate
than the ones I gave above.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

"Ed Huntress" wrote in message
...


--
Ed Huntress
(remove "3" from email address for email reply)
"ATP*" wrote in message
...

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott

Use a transfer punch. You can get a set for about $10. I'm assuming you
mean
1/2" diameter holes?

Or, depending on the configuration, he may be able to just clamp the two
together and drill both at once.

--
Ed Huntress

But that would not require additional tools:-)

In article .com, Scott
says...

Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

Umm, your post is a bit fuzzy about the type of holes you
want to drill.

I can see you have 48 inch long pieces of rectangular
aluminum stock, each piece being 1.0 inch by 0.5 inch
in cross section.

You want to drill holes in the stock. I am guessing they are
to go on the larger, one inch face, and travel all the way
though.

And that you want the hole in the second part to be drilled
at the same point along the 48 inch length.

And you want them to be placed 100%.

I don't know what 100% is, as a machining tolerance.

You need to decide, based on the functional requirements
(what are these parts supposed to do?) on a dimensional
tolerance for the hole locations.

Something like, first hole to be located +/- 0.005 inch
at 10.000 inches along the length of the first part, and
at 0.500 across the width. Second hole in second part
to be located within +/- 0.001 of first hole in first
part.

That sort of thing. If you give more information then
folks can help you in deciding on an appropriate tolerance,
and then picking the best (simplest) technique for
achieving it.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott

An easy way to do that is to make a stop setup on your mill table such that
you can locate the two bars, one at a time, by banking off the stops. Once
you've drilled your first hole, replace the part with the second part and
repeat. Start your hole with a center drill or spotting drill to guarantee
location. If you don't have one, you can use a short split point drill,
which will usually start where you aim it. If the hole size is critical,
don't drill to size in one pass. Drill your hole undersized 1/64", then open
the hole with the proper sized drill bit. That way you get a much cleaner
hole and it's more likely to be size.

The alternative is to stack your parts and drill both of them at the same
time, making sure, in both instances, that you don't drill into the table.
If you can't drill off the side, make sure you are over a T slot, or place
your part(s) on parallels to elevate them enough to miss the table when the
drill breaks through. Use some kerosene, or WD40, to lubricate the drill.
An acid or small paint brush can be used to apply it. You'll get a much
cleaner hole that way, and prevent chips welding to the drill.

Harold

In article .com,
Scott wrote:
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

You've gotten some good advice from others. One thing which I
have not seen addressed is whether the hole is needed within a distance
from the end which is within the capability of your mill, since you say
you have a small one.

If it is not (for example, a hole near the center of the length
of the bars would be well beyond a range where the mill itself could be
used to control the location.

So -- if you don't need the *full* length of the bars, you could
drill through both bars at once so the two holes are the same position
relative to the edges (and there are ways to use the mill to make sure
that you are equidistant from both edges, if that matters to you). Once
the hole exists, place a piece of bar stock of the proper diameter (that
which matches the hole you have drilled), through both pieces, to hold
them in alignment, and while they are held in alignment by the rod, move
to each end, and use the mill to trim the ends to the same length. Then
turn it around and do the other end. (Note, this still does not
guarantee that the hole will be equidistant from both ends.)

So -- if that matters, too, then we will need to come up with
something different to accomplish your requirements for accuracy, once
it is redefined to allowed actual errors, instead of "100%", which is
not achievable -- or if it is, you can't prove it. :-)

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott


..50 cal Barrett...somebody had to say it!

Harold and Susan Vordos wrote:
An easy way to do that is to make a stop setup on your mill table such that
you can locate the two bars, one at a time, by banking off the stops.

I've used this method with good success.

An acid or small paint brush can be used to apply it. You'll get a much
cleaner hole that way, and prevent chips welding to the drill.

This risks catching a brush bristle in the works. I like to drip
cutting fluid on the work with a large hypodermic fitted with a blunted
needle. I'm talking a 30 to 60 cc hypo obtained from a rural pharmacy
or vet supplier.

Ted

"Tom Gardner" wrote in message
...

"Scott" wrote in message
oups.com...
Please be patient wiht me, Im new.

I have 2 1"x1/2"x 48" aluminum bars

I have a small vertical mill. I need to place 2 1/" dia holes in the
same exact location on both bars. How do i drill the forst ane and
ensure 100% placement on the second one?

THanks
Scott


.50 cal Barrett...somebody had to say it!

That would make a nice entry hole, but I think you'd need a bit of
deburring on the back side. BG

Bernd