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Drilling opposing 90 degree holes through round tube

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Dave99

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Jul 5, 2008, 11:14:50 PM7/5/08
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I've been looking for a more accurate way to drill sets of holes 90
degrees from each other through round tube. I came across these V
blocks with clamps...

http://www.grizzly.com/products/90-V-Blocks-w-Clamp-Set-2-1-2-x-2-1-2-x-2-/G9816

I assumed the best way to use them would be to set a fence up on a
press table which centers the bit on the tube, clamp the two blocks to
your piece, then once you do holes on one side you would flip the
blocks over to the next side to get your holes 90 degrees to the first
set. Or possibly use one block and a stationary v-block to put the
other end of the tube into.

Is this the best way to accomplish this, or is there a better way I'm
missing?

Thanks,

Dave

Richard J Kinch

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Jul 5, 2008, 11:23:55 PM7/5/08
to
Dave99 writes:

> Is this the best way to accomplish this, or is there a better way I'm
> missing?

This is really two functions, cylindrical workholding versus 90-degree
indicating.

Vee blocks are one suitable workholding device for cylindrical things. Use
the clamps provided, or pinch the work against a vise jaw with the vee.

Assuming you don't have a precision rotary workholder like a rotary table
or collet holder, you can mark 90 degrees accurately one time on your lathe
chuck and thereafter hold the work in that for scribing. Or at the least
you can wrap paper around the tube and divide that as a template.

Curt Welch

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Jul 6, 2008, 12:17:22 AM7/6/08
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Sounds good to me.

Here's another grizzly item I noticed in their catalog the other day that
could help with that set up...

http://www.grizzly.com/products/Round-Bar-Center-Finder/H2940

--
Curt Welch http://CurtWelch.Com/
cu...@kcwc.com http://NewsReader.Com/

Grant Erwin

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Jul 6, 2008, 1:36:51 AM7/6/08
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Dave99 wrote:

If the tube is small enough so you can get it with a 5C collet, you can use
one of the handy square 5C collet blocks held against a vise stop in the
milling vise. When you're done with one hole, loosen the vise, flip the
block, slide it against the stop, tighten the vise and do the other hole.

Like this one:
http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1806664&PMT4NO=45622504

Grant

Gunner Asch

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Jul 6, 2008, 4:46:44 AM7/6/08
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On Sat, 5 Jul 2008 20:14:50 -0700 (PDT), Dave99 <dpdp...@aol.com>
wrote:


Cheap spin indexer?

Gunner

Political Correctness is a doctrine fostered by a delusional,
illogical liberal minority, and rabidly promoted by an
unscrupulous mainstream media, which holds forth the
proposition that it is entirely possible to pick up a turd by the clean end.

Gunner Asch

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Jul 6, 2008, 4:57:53 AM7/6/08
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Or simply drill/bore the proper sized hole for your tube, in the
center of a rectangular block of steel, drill a hole in each of two
sides, slide in the tube, drill, drop in a pin, turn the block over to
the next hole and drill the second hole. Pull the pin, slide in the
new tube, and repeat.

Cost is nothing to speak but about a half hour of your time

texasjim1093

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Jul 6, 2008, 7:33:00 AM7/6/08
to
Depending on the size and quantity of holes, use wood. It is cheap,
easy and can hold tighter tolerances than you might think. To hold a
tube, just drill a hole then cut a slit on the side of the wood that
will not be in the vise, put a screw in for tightening. If you have
trouble with the drill wobbling on the tube, go with a short bit or
epoxy in a drill jig bushing. For small parts, I buy 2x2 hardwood
blocks from Home depot, a cheap fix for holding parts that are easy to
deform. Good for stand-offs as well.


Joe AutoDrill

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Jul 7, 2008, 8:14:15 AM7/7/08
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> Is this the best way to accomplish this, or is there a better way I'm
> missing?

What is the volume? Are you doing a part a day or a thousand parts a day?
Somewhere in between?

If you have high volume, there is a better way. Drill from both sizes of
the part at the same time... Probably the best way to do this is with an
automatic drill set up. If the placement is really critical, you can
retract the bits into drill bushings each time and have the bushings very
close to the surface of the tube so that the deflection or "bending" of the
drill "bit" is greatly minimized during the process. We have folks holding
very close tolerances with simple set ups like this... But the cost is
higher than a small drill press, that's for sure.

Low volume? The ideas shared by others are better than what I can type.

Let me know if I can help with the high volume solution - even if it means
concept only and not a quote from me.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R

** Posted from http://www.teranews.com **

Jim Wilkins

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Jul 9, 2008, 7:04:38 PM7/9/08
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On Jul 5, 11:14 pm, Dave99 <dpdph...@aol.com> wrote:
> I've been looking for a more accurate way to drill sets of holes 90
> degrees from each other through round tube.
> Dave

A simple way is to clamp the tube into the vee of angle iron and
locate off the two flat sides. You can find the center by lightly
pressing the middle of a 6" ruler against the tubing with the point of
a drill. The drill is centered when the ruler sits level.

That gives good drill-press accuracy if done carefully, but nowhere
nearly as accurate as a milling machine and an index or collet fixture.

The Grumpy Army retiree

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Jan 29, 2018, 3:18:07 PM1/29/18
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replying to Gunner Asch, The Grumpy Army retiree wrote:
Wow,
I just sent your quote to my wife and a few friends....I think you hit the
target "spot on" ...you're making my ribs hurt over here from laughing too
hard!


--
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