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View Full Version : RE: " ...but I don't have a lathe"


mhorowit
July 26th 07, 11:54 AM
In August of '05, Veeduber posted an artical on using a drill press as
a lathe. He describes how to chuck a piece of tubing to turn down it's
diameter. In that case, the center line of the work ran thru the
centerline of the drillpress chuck.

Has anyone seen a scheme for chucking a piece that does not line up
with the center lines? For example: you want to remove the external
threads from one end of a brass elbow. -Mike

Stew Hicks
July 26th 07, 03:04 PM
Is the I.D. such that it can be tapped and chucked on a cut off bolt? If
not, how about a getting a fairly tight fitting bolt or rod and epoxy it in
then chuck and sand off the threads. Even a hardwood dowel might work.





"mhorowit" > wrote in message
ps.com...
> In August of '05, Veeduber posted an artical on using a drill press as
> a lathe. He describes how to chuck a piece of tubing to turn down it's
> diameter. In that case, the center line of the work ran thru the
> centerline of the drillpress chuck.
>
> Has anyone seen a scheme for chucking a piece that does not line up
> with the center lines? For example: you want to remove the external
> threads from one end of a brass elbow. -Mike
>

mhorowit
July 26th 07, 03:28 PM
On Jul 26, 10:04 am, "Stew Hicks" > wrote:
> Is the I.D. such that it can be tapped and chucked on a cut off bolt? If
> not, how about a getting a fairly tight fitting bolt or rod and epoxy it in
> then chuck and sand off the threads. Even a hardwood dowel might work.
>
> "mhorowit" > wrote in message
>
> ps.com...
>
>

Ah! something that will expand and provide something to 'chuck' to.
Thanks - Mike

July 26th 07, 03:39 PM
If all you want to do is remove the threads there's no need to rotate
the part. Clamp it in a vise and use a core drill of suitable size to
remove the threads.

Personally, I'd just wittle a dowel to match the bore of the threaded
end, grease it good, put on a pair of gloves and press the threads
against a 1" wide belt sander. The fitting will spin on the dowel
(and against your glove) whilst the abrasive belt removes the threads.

If you can determine the location of the axis of the threaded bore to
within a thirty-second of an inch or thereabouts you could also solder
a T-nut to the brass fitting, thread a rod into to the T-nut and chuck
the rod, allowing you to remove the threads with a file, sanding disk
or whatever. Finding the center isn't as difficult as it seems since
you can use the drill-press and a piece of dowel to spin the fitting
(by hand) whilst pressing it against the pointed end of a tack driven
through a board... even stiff cardboard would work. The trick here is
to first chuck a pointed scriber and use it to 'index' the point of
the tack (or whatever). Once the two were aligned simply clamp the
board to the table and go about setting up some method of chucking the
fitting. The tack will remain centered relative to the chuck.

Holding irregularly shaped work is a fairly common problem -- even for
people who have lathes :-) There is an almost endless variety of
solutions. The key point is that YOU CAN DO IT if you give it some
thought. (Humans are ingenious rascals. Sometimes I think we're
almost as smart as raccoons :-)

-R.S.Hoover

Dan[_2_]
July 27th 07, 02:33 AM
wrote:
> If all you want to do is remove the threads there's no need to rotate
> the part. Clamp it in a vise and use a core drill of suitable size to
> remove the threads.
>
> Personally, I'd just wittle a dowel to match the bore of the threaded
> end, grease it good, put on a pair of gloves and press the threads
> against a 1" wide belt sander. The fitting will spin on the dowel
> (and against your glove) whilst the abrasive belt removes the threads.
>
> If you can determine the location of the axis of the threaded bore to
> within a thirty-second of an inch or thereabouts you could also solder
> a T-nut to the brass fitting, thread a rod into to the T-nut and chuck
> the rod, allowing you to remove the threads with a file, sanding disk
> or whatever. Finding the center isn't as difficult as it seems since
> you can use the drill-press and a piece of dowel to spin the fitting
> (by hand) whilst pressing it against the pointed end of a tack driven
> through a board... even stiff cardboard would work. The trick here is
> to first chuck a pointed scriber and use it to 'index' the point of
> the tack (or whatever). Once the two were aligned simply clamp the
> board to the table and go about setting up some method of chucking the
> fitting. The tack will remain centered relative to the chuck.
>
> Holding irregularly shaped work is a fairly common problem -- even for
> people who have lathes :-) There is an almost endless variety of
> solutions. The key point is that YOU CAN DO IT if you give it some
> thought. (Humans are ingenious rascals. Sometimes I think we're
> almost as smart as raccoons :-)
>
> -R.S.Hoover
>

I would add: think very carefully about the method you use before you
power up. Even with a lathe it's possible to chuck something unsafely.
Anyone who has experience machining can tell you a story or two about a
work piece going airborne uncommanded or how a knuckle or two can get
smacked.

My personal greatest throw weight was 7 pounds of cast iron. I'd
rather not re-enact that one. The breeze as it flew by my head got my
attention.

Dan, U.S. Air Force, retired

Michael Horowitz
July 27th 07, 08:56 PM
On Thu, 26 Jul 2007 07:39:21 -0700, "
> wrote:

......
> Finding the center [of a threaded bore] isn't as difficult as it seems since
>you can use the drill-press and a piece of dowel to spin the fitting
>(by hand) whilst pressing it against the pointed end of a tack driven
>through a board... even stiff cardboard would work. The trick here is
>to first chuck a pointed scriber and use it to 'index' the point of
>the tack (or whatever). Once the two were aligned simply clamp the
>board to the table and go about setting up some method of chucking the
>fitting. The tack will remain centered relative to the chuck.
>
>-R.S.Hoover

What I've been doing for relatively small holes is find some stock,
use my grinder to make a point with a very flat angle, chuck it and
file to insure the point is centered. Cut off the point and about 3/16
of the stock; drop this pointy-side up into the hole. Now I have a
reference point at the center of the hole.

Now, I'd like to understand the method you are describing (above):
I'm familiar with the trick of chucking a needle (or something very
small; I think there is something called a 'wiggler'??) and aligning
that with a point on the work. you seem to be transfering the location
of the tip of the needle to the tip of the tack on the drill press
table. Then you go on to find someway to chuck the irregular work.
Now I'm left with an irregularly chucked work and a reference point on
a board clamped to the drillpress table, very closely aligned with the
drillpress spindle. What does that buy me?? :) - Mike

July 27th 07, 10:09 PM
Then you go on to find someway to chuck the irregular work.
> Now I'm left with an irregularly chucked work and a reference point on
> a board clamped to the drillpress table, very closely aligned with the
> drillpress spindle. What does that buy me?? :) - Mike
----------------------------------------------------------------------------------------

You use a 'spud' -- anything that marries the part to the chuck in a
concentric fashion -- and use it to press the part against the tack/
center/whatever.

Once you know where the center falls you may drill & tap to use a bolt
as your new chucking piece, or attach a T-nut, centered on the new
mark, and so forth.

The purpose of the tack & cardboard is to transfer the center-point to
the opposite side of the irregularly shaped part, with the
understanding that using a tack and piece of cardboard is meant to
illustrate how the thing could be made up of whatever materials were
on hand.

-R.S.Hoover

Stealth Pilot[_2_]
July 28th 07, 12:31 PM
On Fri, 27 Jul 2007 14:09:54 -0700, "
> wrote:

> Then you go on to find someway to chuck the irregular work.
>> Now I'm left with an irregularly chucked work and a reference point on
>> a board clamped to the drillpress table, very closely aligned with the
>> drillpress spindle. What does that buy me?? :) - Mike
>----------------------------------------------------------------------------------------
>
>You use a 'spud' -- anything that marries the part to the chuck in a
>concentric fashion -- and use it to press the part against the tack/
>center/whatever.
>
>Once you know where the center falls you may drill & tap to use a bolt
>as your new chucking piece, or attach a T-nut, centered on the new
>mark, and so forth.
>
>The purpose of the tack & cardboard is to transfer the center-point to
>the opposite side of the irregularly shaped part, with the
>understanding that using a tack and piece of cardboard is meant to
>illustrate how the thing could be made up of whatever materials were
>on hand.
>
>-R.S.Hoover

if you used parts out of the aircraft spruce cattle dog you'd find
that there was no need to make an oddball part.
the cattle dog has the complete set of parts described in it.

....and a complete set of light weight anodised blue parts.

Stealth Pilot

Michael Horowitz
July 28th 07, 05:16 PM
On Sat, 28 Jul 2007 19:31:00 +0800, Stealth Pilot
> wrote:

>
>
>if you used parts out of the aircraft spruce cattle dog you'd find
>that there was no need to make an oddball part.
>the cattle dog has the complete set of parts described in it.
>
>...and a complete set of light weight anodised blue parts.
>
>Stealth Pilot


Threw me for a moment. "aircraft spruce cattle dog" sounded too much
like "Home Depot Aero Space" - couldn't tell for a moment what you
ment :) Thanks for the pointer. - MikeH

Stealth Pilot[_2_]
July 29th 07, 03:22 PM
On Sat, 28 Jul 2007 12:16:25 -0400, Michael Horowitz
> wrote:

>On Sat, 28 Jul 2007 19:31:00 +0800, Stealth Pilot
> wrote:
>
>>
>>
>>if you used parts out of the aircraft spruce cattle dog you'd find
>>that there was no need to make an oddball part.
>>the cattle dog has the complete set of parts described in it.
>>
>>...and a complete set of light weight anodised blue parts.
>>
>>Stealth Pilot
>
>
>Threw me for a moment. "aircraft spruce cattle dog" sounded too much
>like "Home Depot Aero Space" - couldn't tell for a moment what you
>ment :) Thanks for the pointer. - MikeH

there are a range of adverts in australia not using the word 'catalog'
one describes it as a cattle dog.
one is a cartoon advert ot tradesman dogs who look up things in the
dogalog. catalogs being, of course, for cat tradesmen.

we genuinely do have an australian culture.
Stealth Pilot

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