Aluminum Jig plate...
Phil Koenig
sub-plates for milling. First off, I've done a search and came up with
very little info other than one outfit selling it for well over a dollar
a cubic inch. Ouch! Is that a typical price? Aside from that, as I
understand it, the material is cast and stress relieved. Is it flat
enough to use in that condition, or do I have to face/fly cut it to get
it into a reasonably flat condition. I'm not doing aerospace work, but
I'd like to be fairly accurate, as I anticipate using these fixtures
over and over. Lastly, is this even a good idea?
Philfthy
PLAlbrecht
Jack Erbes
>
> I'm interested in obtaining some of this stuff to make modular
> sub-plates for milling. First off, I've done a search and came up with
> very little info other than one outfit selling it for well over a dollar
> a cubic inch.
That must be something a little out of the ordinary. You can buy mill
finish 6061-T6 plates as scrap for $1.50 a pound or so and bolted to a
flat table they will usually fall with a few thousandths or less in
thickness all the way across.
If you bolt one down and face it flat it may not stay flat when removed
(do to changes in stresses, etc.) but should come back to flat again if
rebolted.
I sure the cast ones have some attributes that make them worth the money
to someone. But you would probably do well to experiment with making a
jig or two from less expensive stuff. I would be surprised that the
accuracy was not satisfactory for the work you describe.
--
Jack in Sonoma, CA, USA (ja...@vom.com)
Phil Koenig
Jack Erbes wrote:
> Phil Koenig wrote:
> >
> > I'm interested in obtaining some of this stuff to make modular
> > sub-plates for milling. First off, I've done a search and came up with
> > very little info other than one outfit selling it for well over a dollar
> > a cubic inch.
>
> That must be something a little out of the ordinary. You can buy mill
> finish 6061-T6 plates as scrap for $1.50 a pound or so and bolted to a
> flat table they will usually fall with a few thousandths or less in
> thickness all the way across.
Jack-
It's not been my experience that I could count on ANYTHING to be anything like
flat, or even close.
>
>
> If you bolt one down and face it flat it may not stay flat when removed
> (do to changes in stresses, etc.) but should come back to flat again if
> rebolted.
well, as I understand it the whole point of a "stress relieved" material is
that it "relieves"
that problem. what you say may be absolutely true where it comes to AL, but
it's
something I don't.
The other part of this equation, as I've thought about it, is that I want
whatever flatness I can possibly
get, becauce whatever "outtage" I have is going to magnified the farther I get
away from the plate in the Z axis. Having seen too often how these small
dimensions get magnified out in space, I'll do what I can to keep the plate
flat to within a 50 billionth...uh, strike that. Just make it as tight as the
table and I'd be ecstatic.
>
>
> I sure the cast ones have some attributes that make them worth the money
> to someone. But you would probably do well to experiment with making a
> jig or two from less expensive stuff. I would be surprised that the
> accuracy was not satisfactory for the work you describe.
As always, the proof is in the puddin' (so to speak). I have some common 6061
in 1X4" of known origin.
I'll clamp it to the table and indicate it and see what's up.
Philfthy
ron ginger
>
> I'm interested in obtaining some of this stuff to make modular
> sub-plates for milling.
The Metal Source in Reading MA sell the stuff by the pound, for about
$1.50 or so. They sell a huge range of sizes, and will take phone orders
and ship UPS.
They have a web site under the parent company Admirial Metals. DOnt have
a URL on hand.
ron
Ned Simmons
that jig plate is not all that much more than regular 6061 plate, maybe
1-1/2 to 2X as much. The last time I bought a quantity of al it was under
$2/pound. $1/cubic inch is $10/lb.
Jig plate has already been surfaced after casting and is much flatter
than regular plate, but I can't put my hands on a spec. It can also be
ugly to machine, it's often quite soft and gummy. If you're using it for
fixtures I'd plan on using inserts on any threads that are made up
repeatedly.
I occasionally buy 6061 aluminum pieces saw cut to size, in that case the
place I use sends what is marked as "tooling plate". This is apparently
regular plate that has been subjected to a surfacing operation similar to
jig plate. I don't know how it's flatness compares to jig plate, but it
might be worth checking into.
Ned Simmons
In article <39F761C5...@tuna.net>, ph...@tuna.net says...
> I'm interested in obtaining some of this stuff to make modular
> sub-plates for milling. First off, I've done a search and came up with
> very little info other than one outfit selling it for well over a dollar
CutMetals
Unlike typical 6061 plate Mic 6 is a cast plate that IS dead nuts flat. Also,
it won't move it's totally stable and 1/2" is 1/2".
Usually you will find small quantities for
$4.50-$5.50/# I can supply this and typical
6061 plate too. I haven't put it on my site yet but if you E-mail me I'll quote
you custom cut stock in each. Cutmetals.com
Mike Henry
what looked like aluminum jig plate. They have a chucnk of 7075 up now:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=473615569
Phil Koenig <ph...@tuna.net> wrote in message
news:39F761C5...@tuna.net...
who writes
>ugly to machine, it's often quite soft and gummy.
I made a jig plate straddle milling jig in the NVCC shop class and straddle
milled cast jig plates for our drill jigs. A nice young lady, I think the one
featured on one of the old brochures, turned all the plates and just like you
said, they were gummy, and dead nuts flat. Very stable.
We should have annealed them. Oh, well. We recycled almost all our chips!
Yours,
Doug Goncz
Replikon Research (Seven Corners, VA)
Remembering Linda Newbery 1959-2000
http://members.aol.com/DGoncz/www.fahs.org_lguestbook.htm
Courtesy Frankfurt American High School organization at www.fahs.org
Edward Haas
if need be. They'll Blanchard grind it too, if you require that kind of
tolerance. Sorry, no number handy; try 800 information.
--
"Steamboat Ed" Haas : The world is my oyster
Watch link rot in action! : ...but it's October...
http://www.nmpproducts.com
---Decks a-wash in a sea of words---
Phil Koenig
Edward Haas wrote:
> --Call TCI Aluminum; they make the stuff and will cut it to size
> if need be. They'll Blanchard grind it too, if you require that kind of
> tolerance.
OK, I'm more than willing to admit my ignorance...blanchard grind...Speak
Haas!
And thank you for being around.
Philfthy
Gal...@berkshire.net
stock. I'm sure there are better types of aluminum for this. 7075 may
be one. I normaly facemill the surface before I press in the dowel
pins. Then I know the surface is square to the spindle. Since I do
short production runs I don't make dedicated jigs. Instead I drill and
tap a bolt pattern for 1/2-13 screws and a hole pattern for press fit
1/4" dowel pins. When the job is done I press out the pins. Next time I
use the plate I face off any mill markings and start over. For small
parts I clamp the jigplate in a vice to save time. I'm kicking around
the idea of making these plates when work slows and try selling them on
e-bay. Do you think something like that would sell?
Regards,
Galaxy
> I'm interested in obtaining some of this stuff to make modular
> sub-plates for milling. First off, I've done a search and came up with
> very little info other than one outfit selling it for well over a
dollar
> a cubic inch. Ouch! Is that a typical price? Aside from that, as I
> understand it, the material is cast and stress relieved. Is it flat
> enough to use in that condition, or do I have to face/fly cut it to
get
> it into a reasonably flat condition. I'm not doing aerospace work, but
> I'd like to be fairly accurate, as I anticipate using these fixtures
> over and over. Lastly, is this even a good idea?
> Philfthy
>
>
Sent via Deja.com http://www.deja.com/
Before you buy.
John Wasser
In article <39F8E2E6...@tuna.net>, Phil Koenig <ph...@tuna.net>
wrote:
> OK, I'm more than willing to admit my ignorance...blanchard grind...Speak
> Haas!
I found a mention that Blanchard grinding uses an abrasive disk
spinning in a plane PARALLEL to the surface being ground rather than
the perpendicular spin of a regular surface grinder.
Here is a reference:
http://iprod.auc.dk/mantech/material/steels/glossary/glostext.htm
Blanchard (Rotary) Grinding
The process of abrasive machining flat surfaces utilizing the face of a
grinding wheel mounted on a vertical spindle. Work pieces are held in
place by a magnetic chuck that rotates under the grinding wheel.
Blanchard grinding, because the large area of the wheel face is in
contact with the work piece, produces heavy stock removal and a
distinctive crosshatch pattern of grinding marks. Blanchard grinding is
the choice when maximum production, moderate finishes, and moderate
accuracy are required.
The term "Blanchard grinding" is a generic term derived from the
Blanchard Machine Company, which specializes in manufacturing rotary
grinding machines. There has been a movement in the grinding industry
to change the term to "rotary grinding." Traditions are hard to break,
and Blanchard grinding continues to be an accepted term for this type
of abrasive machining.
Tolerance range: +/-.001 to +/-.003 on size; .001 to .002 on
parallelism, and 63 to 125 micro finish. Flatness varies with the
application. Tolerances are dependent on the type of material and
physical characteristics of the work pieces, and can be held closer in
limited applications.
mark rand
http://www.pegpro.co.uk/images/lumsd-02.jpg
"John Wasser" <Newsgrou...@John-Wasser.com> wrote in message
news:271020001852028472%Newsgrou...@John-Wasser.com...
Gal...@berkshire.net
> place by a magnetic chuck that rotates under the grinding wheel.
Just wondering what is used to hold non magnetic material. Maybe a
vacuum chuck.
Regards,
Galaxy
Jack Erbes
>
> Work pieces are held in
> > place by a magnetic chuck that rotates under the grinding wheel.
>
> Just wondering what is used to hold non magnetic material. Maybe a
> vacuum chuck.
>
> Regards,
> Galaxy
The Blanchard grinder I saw was a real Blanchard. The table was like a
large rotary table and had t-solts in it for clamping either vises or
work.
If I recall right, the grinding segments were shaped like they were cut
from a grinding wheel divided into 4 or 6 equal pieces (like a pie with
a hold in the center) and then cemented to a mounting plate.
The stones were mounted up into a big cupped rotating head on the
vertical spindle and dressed by running it over a dresser set up on the
table. And I seem to recall that the rotating head also moved in
circles as it rotated, and that is what produces the characteristic
elliptical swirls on the surface. I don't recall if the table turned
also by maybe it did.
I about 1990 I paid an old gentleman $40 to regrind a cast iron surface
plate for me on his Blanchard grinder and was extremely happy with the
results. When I asked him what he thought the surface flatness was he
said probably a few millionths over all and a small fraction of a
millionth as far as surface roughness.