I need to make a slot with square ends in a steel bar (0.25" wide and
about 0.5" long). I'm thinking of using a 2 flute end mill and then
sqaring up the corners with a file but wonder if there is a more precise
way do do this with a broach or something? Any suggestions?

Thanks

Dan Miller
Seattle WA.

Dan Miller wrote:

I need to make a slot with square ends in a steel bar (0.25" wide and
about 0.5" long). I'm thinking of using a 2 flute end mill and then
sqaring up the corners with a file but wonder if there is a more precise
way do do this with a broach or something? Any suggestions?

Thanks

Dan Miller
Seattle WA.

Is this a through slot or a blind slot? If it's a through slot, then
you can use a 1/4" lathe bit and stroke the slot end square using a
mill quill or lathe carriage feed. Or, you can broach the hole if you
go to the trouble of making up a guide. If it's a blind slot, then you
could EDM it, I suppose.

GWE

Sounds like a job for a shaper.

Harry C.

"Dan Miller" wrote in message
...
I need to make a slot with square ends in a steel bar (0.25" wide and about
0.5" long). I'm thinking of using a 2 flute end mill and then sqaring up
the corners with a file but wonder if there is a more precise way do do
this with a broach or something? Any suggestions?


Me thinks you mean a pocket 0.250" x 0.500" x ?? deep. If'n you don't have
an EDM handy, consider drilling four very small holes at the pocket corners
first, gets rid of most of your filing work. If your part can stand it,
drill right at the corners so you actually make the pocket a bit wider and
longer right in the corner. With a very small drill, the extra clearance is
almost undetectable.

Follow up from here with a small endmill.

If you mean a through hole, then its very easy to just file the corners
square. Or broach on a lathe.

Karl

1] Calculate the four corners and drill 4 tiny holes so that they are
tangent to the corners. Rough with your choice of end mills and fnish
with the smallest you can get for your depth, there will be minimal
material to file away

2] Call the engineer and see if he really needs em square cornered[my
personal favorite method]

What is the procedure for broaching on a lathe? I thought it was done using
a press. Since I have no experience with the procedure, could you be more
specific?

thanks
T.Alan


"Karl Townsend" remove .NOT to reply wrote
in message nk.net...

.....Or broach on a lathe.

Karl

Have you considered a Watts Brothers Tool Works floating chuck drill? Truly
amazing tool for boring square, hexagonal and octagonal holes. 'Tain't
cheap but fun to watch.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Dan Miller" wrote in message
...
I need to make a slot with square ends in a steel bar (0.25" wide and
about 0.5" long). I'm thinking of using a 2 flute end mill and then
sqaring up the corners with a file but wonder if there is a more precise
way do do this with a broach or something? Any suggestions?

Thanks

Dan Miller
Seattle WA.

Glenn Ashmore wrote:
Have you considered a Watts Brothers Tool Works floating chuck drill? Truly
amazing tool for boring square, hexagonal and octagonal holes. 'Tain't
cheap but fun to watch.





Watts Brothers Tool Works 760 Airbrake Ave Wilmerding, PA, 412-823-7877

Theory
http://upper.us.edu/faculty/smith/reuleaux.htm



--
- -
Rex Burkheimer
WM Automotive
Fort Worth TX

"T.Alan Kraus" wrote in message
...
What is the procedure for broaching on a lathe? I thought it was done
using
a press. Since I have no experience with the procedure, could you be more
specific?


This is easy to show, hard to describe. In this case, for 1/4" square, mount
a 1/4" tool bit in a tool holder so its aligned with the axis of the lathe.
Sharpen bit so it cuts on one side. With the lathe off, and your part held
in a faceplate, four jaw, or whatever, rock the carriage back and forth.
Move cross slide to incease depth of cut. I've seen an article on this
somewhare, maybe someone can post a link.

Same idea can also be done on the mill, but the quill lever is nowhere near
as stout. easy to break something in your mill.

Karl

Karl Townsend wrote:
"T.Alan Kraus" wrote in message
...

What is the procedure for broaching on a lathe? I thought it was done
using
a press. Since I have no experience with the procedure, could you be more
specific?



This is easy to show, hard to describe. In this case, for 1/4" square, mount
a 1/4" tool bit in a tool holder so its aligned with the axis of the lathe.
Sharpen bit so it cuts on one side. With the lathe off, and your part held
in a faceplate, four jaw, or whatever, rock the carriage back and forth.
Move cross slide to incease depth of cut. I've seen an article on this
somewhare, maybe someone can post a link.

Same idea can also be done on the mill, but the quill lever is nowhere near
as stout. easy to break something in your mill.

One of the old PM articles showed how to make a lever-operated broach
that attaches to the tailstock. Looked a lot like a collet closer.
You could hold the work in the chuck or mounted to the crossslide or
toolpost.

--
- -
Rex Burkheimer
WM Automotive
Fort Worth TX

Rex B wrote:

One of the old PM articles showed how to make a lever-operated broach
that attaches to the tailstock. Looked a lot like a collet closer.
You could hold the work in the chuck or mounted to the crossslide or
toolpost.

Anyone have that article? I'd like to see how this is done, too.


--
Gary Brady
Austin, TX
www.powdercoatoven.4t.com

Back (way back) in high school, my welding teach could make perfect
1/2"X 3/4" slots in 1/2" plate with a cutting torch. Truly amazing; he
would just casually place the tip in position and zip-zip-zip-zip, there
it was. Very square corners and right-angle walls.
JR
Dweller in the cellar

Dan Miller wrote:
I need to make a slot with square ends in a steel bar (0.25" wide and
about 0.5" long). I'm thinking of using a 2 flute end mill and then
sqaring up the corners with a file but wonder if there is a more precise
way do do this with a broach or something? Any suggestions?

Thanks

Dan Miller
Seattle WA.


--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
If you're not the lead dog, the view never changes
Doubt yourself, and the real world will eat you alive
The world doesn't revolve around you, it revolves around me
No skeletons in the closet; just decomposing corpses
--------------------------------------------------------------
Dependence is Vulnerability:
--------------------------------------------------------------
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"I'm sorry, Dave, I'm afraid I can't do that.."

"Grant Erwin" wrote in message
...

Is this a through slot or a blind slot? If it's a through slot, then
you can use a 1/4" lathe bit and stroke the slot end square using a
mill quill or lathe carriage feed.


Even if it is a blind slot you can rig a lathe bit as a broach. To do this
you need to cut a slot in a piece of rod to retain the tool bit. The idea
here is to restrain the tool bit in the rod so you can stroke the quill and
the cutting edge of the tool bit can nibble away with each stroke.

You lock the brake on the spindle tale a small cut, advance the table a few
thousands and stroke, advance, stroke, advance etc.

This goes pretty fast.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.

Dan Miller Mar 9, 8:10 am show options

Newsgroups: rec.crafts.metalworking
From: Dan Miller - Find messages by this author
Date: Wed, 09 Mar 2005 08:10:28 -0800
Local: Wed, Mar 9 2005 8:10 am
Subject: making sqare holes in steel
Reply | Reply to Author | Forward | Print | Individual Message | Show
original | Report Abuse

I need to make a slot with square ends in a steel bar (0.25" wide and
about 0.5" long). I'm thinking of using a 2 flute end mill and then
sqaring up the corners with a file but wonder if there is a more
precise
way do do this with a broach or something? Any suggestions?


Thanks


Dan Miller


Shaper, or a shaper head on a Bridgeport.

John Martin

Great, thanks for all of the suggestions. I'll give it a try. the slot
is through so that should simplify things. I'll mill with a two flute
cutter first and square up the ends with a 0.25" bit. Problem will be
holding the bit but I think I can drill a hole in a piece of drill rod
and set a 0.25 bit at a 45 degree angle to the rod with a set screw
inserted along the axis to hold it in place. That way the tip can reach
the far side of the slot without the holder having to enter. I guess the
other option is to use a bit holder that will fit in the slot, mount the
bit perpendicular to the bar, and scrape one corner at a time with say a
0.125 bit. The slot dimensions are 0.25 wide by 0.5 long through a 5/8
round bar.

Additional suggestions welcome.

Thanks

Dan


Roger Shoaf wrote:

"Grant Erwin" wrote in message
...


Is this a through slot or a blind slot? If it's a through slot, then
you can use a 1/4" lathe bit and stroke the slot end square using a
mill quill or lathe carriage feed.




Even if it is a blind slot you can rig a lathe bit as a broach. To do this
you need to cut a slot in a piece of rod to retain the tool bit. The idea
here is to restrain the tool bit in the rod so you can stroke the quill and
the cutting edge of the tool bit can nibble away with each stroke.

You lock the brake on the spindle tale a small cut, advance the table a few
thousands and stroke, advance, stroke, advance etc.

This goes pretty fast.

Aha! Thanks,
T.Alan


"Karl Townsend" remove .NOT to reply wrote
in message ink.net...

This is easy to show, hard to describe. In this case, for 1/4" square,
mount
a 1/4" tool bit in a tool holder so its aligned with the axis of the
lathe.
Sharpen bit so it cuts on one side. With the lathe off, and your part held
in a faceplate, four jaw, or whatever, rock the carriage back and forth.
Move cross slide to incease depth of cut. I've seen an article on this
somewhare, maybe someone can post a link.

Same idea can also be done on the mill, but the quill lever is nowhere
near
as stout. easy to break something in your mill.

Karl

In article ,
Dan Miller wrote:
Great, thanks for all of the suggestions. I'll give it a try. the slot
is through so that should simplify things. I'll mill with a two flute
cutter first and square up the ends with a 0.25" bit. Problem will be
holding the bit but I think I can drill a hole in a piece of drill rod
and set a 0.25 bit at a 45 degree angle to the rod with a set screw
inserted along the axis to hold it in place. That way the tip can reach
the far side of the slot without the holder having to enter. I guess the
other option is to use a bit holder that will fit in the slot, mount the
bit perpendicular to the bar, and scrape one corner at a time with say a
0.125 bit. The slot dimensions are 0.25 wide by 0.5 long through a 5/8
round bar.

How deep is your slot? Why not mount the 1/4" bit end on, and
just grind enough of a rake on the end to let it cut well as you crank
it in? No real need for your proposed 45 degree slot.

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 ---

Gary Brady wrote:
Rex B wrote:

One of the old PM articles showed how to make a lever-operated broach
that attaches to the tailstock. Looked a lot like a collet closer.
You could hold the work in the chuck or mounted to the crossslide or
toolpost.


Anyone have that article? I'd like to see how this is done, too.


I can dig it up on my home PC. I'll try to do that.

--
- -
Rex Burkheimer
WM Automotive
Fort Worth TX

Karl Townsend wrote:

"T.Alan Kraus" wrote in message
...

What is the procedure for broaching on a lathe? I thought it was done
using
a press. Since I have no experience with the procedure, could you be more
specific?



This is easy to show, hard to describe. In this case, for 1/4" square, mount
a 1/4" tool bit in a tool holder so its aligned with the axis of the lathe.
Sharpen bit so it cuts on one side. With the lathe off, and your part held
in a faceplate, four jaw, or whatever, rock the carriage back and forth.
Move cross slide to incease depth of cut. I've seen an article on this
somewhare, maybe someone can post a link.

Same idea can also be done on the mill, but the quill lever is nowhere near
as stout. easy to break something in your mill.

Karl





It's a good 'trick' for occasional light use. When doing this, you are
basically using the lathe as a shaper, or slotter (a specialized
shaper). The lathe's moving carriage becomes, in effect, the ram of the
shaper.

Dan Mitchell
============

Rex B wrote:

Karl Townsend wrote:

"T.Alan Kraus" wrote in message
...

What is the procedure for broaching on a lathe? I thought it was done
using
a press. Since I have no experience with the procedure, could you be
more
specific?




This is easy to show, hard to describe. In this case, for 1/4" square,
mount a 1/4" tool bit in a tool holder so its aligned with the axis of
the lathe. Sharpen bit so it cuts on one side. With the lathe off, and
your part held in a faceplate, four jaw, or whatever, rock the
carriage back and forth. Move cross slide to incease depth of cut.
I've seen an article on this somewhare, maybe someone can post a link.

Same idea can also be done on the mill, but the quill lever is nowhere
near as stout. easy to break something in your mill.


One of the old PM articles showed how to make a lever-operated broach
that attaches to the tailstock. Looked a lot like a collet closer.
You could hold the work in the chuck or mounted to the crossslide or
toolpost.

Many lathes have lever operated tailstock rams. These would be
acceptable for LIGHT use such as suggested. The typical lever tailstock
mechanism on a lathe is much weaker in construction than the typical
lever operated 'armstrong' shaper.

Dan Mitchell
============

Can you heat the workpiece to a cherry red? Make a drift from your 1/4 inch
toolbit by tapering to the drill size, then drive it through the workpiece
at forging heat. Since no metal is removed, the workpiece will bulge - you
can file/machine/grind it off when cold. Dimensions and square corners will
be perfect. If the workpiece is brass or aluminum maybe you can do it cold.