I have some 1/2"-thick steel plate (don't know composition, it isn't
stainless) from which I'd like to make two make two 12"-diameter disks.
Each disk also needs a 3"-diameter center hole, and a pattern of
fairly-precise though holes for bolts. Think of something like a
simple brake disk.

I think I could rough-cut them with my torch and then pay someone with
a lathe to finish the job. They could chuck up on the outer rim as
best they could, cut the center hole, then chuck up on that to finish
the rim and mark a circle for the through holes, then drill them on a
press.

I've also heard of a process called "water cutting", whereby a
high-pressure water stream is used to separate material. I am
concerned about heat warpage if I flame-cut the disks, they must remain
flat and true. Can water-cutting be used on 1/2" steel?

I suppose wire-EDM is also a possibility, but it sounds expensive.

What procedure should I consider, and how much should I expect to pay?

thanks,

Martin

"Martin" wrote in message
oups.com...
I have some 1/2"-thick steel plate (don't know composition, it isn't
stainless) from which I'd like to make two make two 12"-diameter disks.
Each disk also needs a 3"-diameter center hole, and a pattern of
fairly-precise though holes for bolts. Think of something like a
simple brake disk.

I think I could rough-cut them with my torch and then pay someone with
a lathe to finish the job. They could chuck up on the outer rim as
best they could, cut the center hole, then chuck up on that to finish
the rim and mark a circle for the through holes, then drill them on a
press.

I've also heard of a process called "water cutting", whereby a
high-pressure water stream is used to separate material. I am
concerned about heat warpage if I flame-cut the disks, they must remain
flat and true. Can water-cutting be used on 1/2" steel?

water jet, and yes. you could also retrue them after flame cutting.

I suppose wire-EDM is also a possibility, but it sounds expensive.

What procedure should I consider, and how much should I expect to pay?

water jet is about $1/inch. there may be a setup fee.


thanks,

Martin

On Fri, 25 Feb 2005 14:51:58 -0700, "Charles Spitzer"
wrote:


What procedure should I consider, and how much should I expect to pay?

water jet is about $1/inch. there may be a setup fee.

I send work to a waterjet place. I cannot say enough good about it.
I am having fairly intricate parts cut from plate that USED to be
machined, brazed, machined. Now all I do is clean up the slight draft
on one surface where I have to, throw them in the vibratory tumble for
a day, and they are all done. The parts are 304 SS cutting from 1/2"
thick plate. Most places I have seen, you e-mail them a DXF or DWG
file, and then they load the machine and the drawing and go off and do
something else.
A Mach 1 jet of water loaded with garnet abrasive does not seem to
care much what the anneal condition of the metal is, and the nice
thing is that unlike torch or plasma, no annealing happens at the cut.
It punches its own starting holes, too.

Water jet cutting is the way to go for you. One thing that concerns me is
the fact that you do not know the composition of your steel. If this is a
critical part (Like a brake disk) rather than a sign base or something, you
might wish to consider the material selection carefully before you make it.

--

Roger Shoaf

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

"Martin" wrote in message
oups.com...
I have some 1/2"-thick steel plate (don't know composition, it isn't
stainless) from which I'd like to make two make two 12"-diameter disks.
Each disk also needs a 3"-diameter center hole, and a pattern of
fairly-precise though holes for bolts. Think of something like a
simple brake disk.

I think I could rough-cut them with my torch and then pay someone with
a lathe to finish the job. They could chuck up on the outer rim as
best they could, cut the center hole, then chuck up on that to finish
the rim and mark a circle for the through holes, then drill them on a
press.

I've also heard of a process called "water cutting", whereby a
high-pressure water stream is used to separate material. I am
concerned about heat warpage if I flame-cut the disks, they must remain
flat and true. Can water-cutting be used on 1/2" steel?

I suppose wire-EDM is also a possibility, but it sounds expensive.

What procedure should I consider, and how much should I expect to pay?

thanks,

Martin

On Fri, 25 Feb 2005 15:23:50 -0800, "Roger Shoaf"
wrote:

Water jet cutting is the way to go for you. One thing that concerns me is
the fact that you do not know the composition of your steel. If this is a
critical part (Like a brake disk) rather than a sign base or something, you
might wish to consider the material selection carefully before you make it.


Cutting Edge
____________________________

Work: 909-948-1496


Rancho Cucamonga California.

Waterjet and other types of materials cutting.

tell em Gunner, the OmniTurn tech refered you.


It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

Thanks! I will look into local cost of water-cutting. Working from an
autocad-output file is perfect. If I draw the small desired through
holes at "finished" size, for example 3/8" id, how close could I
reasonably expect them to be? If I need good enough accuracy for
threading, do I need to ask for them undersize just to get
computer-accurate locatioin, then ream or drill? Will the water-cut
holes be noticeably tapered?

Martin

Grunty Grogan wrote:
On Fri, 25 Feb 2005 14:51:58 -0700, "Charles Spitzer"
wrote:


What procedure should I consider, and how much should I expect to
pay?

water jet is about $1/inch. there may be a setup fee.

I send work to a waterjet place. I cannot say enough good about it.
I am having fairly intricate parts cut from plate that USED to be
machined, brazed, machined. Now all I do is clean up the slight
draft
on one surface where I have to, throw them in the vibratory tumble
for
a day, and they are all done. The parts are 304 SS cutting from 1/2"
thick plate. Most places I have seen, you e-mail them a DXF or DWG
file, and then they load the machine and the drawing and go off and
do
something else.
A Mach 1 jet of water loaded with garnet abrasive does not seem to
care much what the anneal condition of the metal is, and the nice
thing is that unlike torch or plasma, no annealing happens at the
cut.
It punches its own starting holes, too.

the measurements will be spot on if the guy running the machine is good.

it won't cut tapered holes, see item 1. the precision has to do with the
pressure and linear speed of the jet. if it moves too fast, the cutting hole
wanders and it doesn't cut all the way through, messing up the end (bottom
of the hole) where it runs out of steam.

you should ask these questions of the person you contract with to see what
their requirements are.

"Martin" wrote in message
oups.com...
Thanks! I will look into local cost of water-cutting. Working from an
autocad-output file is perfect. If I draw the small desired through
holes at "finished" size, for example 3/8" id, how close could I
reasonably expect them to be? If I need good enough accuracy for
threading, do I need to ask for them undersize just to get
computer-accurate locatioin, then ream or drill? Will the water-cut
holes be noticeably tapered?

Martin

Grunty Grogan wrote:
On Fri, 25 Feb 2005 14:51:58 -0700, "Charles Spitzer"
wrote:


What procedure should I consider, and how much should I expect to
pay?

water jet is about $1/inch. there may be a setup fee.

I send work to a waterjet place. I cannot say enough good about it.
I am having fairly intricate parts cut from plate that USED to be
machined, brazed, machined. Now all I do is clean up the slight
draft
on one surface where I have to, throw them in the vibratory tumble
for
a day, and they are all done. The parts are 304 SS cutting from 1/2"
thick plate. Most places I have seen, you e-mail them a DXF or DWG
file, and then they load the machine and the drawing and go off and
do
something else.
A Mach 1 jet of water loaded with garnet abrasive does not seem to
care much what the anneal condition of the metal is, and the nice
thing is that unlike torch or plasma, no annealing happens at the
cut.
It punches its own starting holes, too.

To learn the basics of waterjet / abrasivejet cutting and machining,
visit:

http://www.waterjets.org

For a list of places with waterjets that can do work for you, visit:

http://www.waterjets.org/waterjet_jobshops.html
http://www.waterjets.org/internation..._jobshops.html
or
http://www.omax.com/job_shop_match.html

- Carl.
Waterjet Web Reference
http://www.waterjets.org


Martin wrote:
Thanks! I will look into local cost of water-cutting. Working from
an
autocad-output file is perfect. If I draw the small desired through
holes at "finished" size, for example 3/8" id, how close could I
reasonably expect them to be? If I need good enough accuracy for
threading, do I need to ask for them undersize just to get
computer-accurate locatioin, then ream or drill? Will the water-cut
holes be noticeably tapered?

Martin

Grunty Grogan wrote:
On Fri, 25 Feb 2005 14:51:58 -0700, "Charles Spitzer"
wrote:


What procedure should I consider, and how much should I expect
to
pay?

water jet is about $1/inch. there may be a setup fee.

I send work to a waterjet place. I cannot say enough good about
it.
I am having fairly intricate parts cut from plate that USED to be
machined, brazed, machined. Now all I do is clean up the slight
draft
on one surface where I have to, throw them in the vibratory tumble
for
a day, and they are all done. The parts are 304 SS cutting from
1/2"
thick plate. Most places I have seen, you e-mail them a DXF or DWG
file, and then they load the machine and the drawing and go off and
do
something else.
A Mach 1 jet of water loaded with garnet abrasive does not seem to
care much what the anneal condition of the metal is, and the nice
thing is that unlike torch or plasma, no annealing happens at the
cut.
It punches its own starting holes, too.

VERY informative site. Many thanks.

Martin

Carl wrote:
To learn the basics of waterjet / abrasivejet cutting and machining,
visit:

http://www.waterjets.org

For a list of places with waterjets that can do work for you, visit:

http://www.waterjets.org/waterjet_jobshops.html
http://www.waterjets.org/internation..._jobshops.html
or
http://www.omax.com/job_shop_match.html

- Carl.
Waterjet Web Reference
http://www.waterjets.org


Martin wrote:
Thanks! I will look into local cost of water-cutting. Working
from
an
autocad-output file is perfect. If I draw the small desired
through
holes at "finished" size, for example 3/8" id, how close could I
reasonably expect them to be? If I need good enough accuracy for
threading, do I need to ask for them undersize just to get
computer-accurate locatioin, then ream or drill? Will the
water-cut
holes be noticeably tapered?

Martin

Grunty Grogan wrote:
On Fri, 25 Feb 2005 14:51:58 -0700, "Charles Spitzer"
wrote:


What procedure should I consider, and how much should I expect
to
pay?

water jet is about $1/inch. there may be a setup fee.

I send work to a waterjet place. I cannot say enough good about
it.
I am having fairly intricate parts cut from plate that USED to be
machined, brazed, machined. Now all I do is clean up the slight
draft
on one surface where I have to, throw them in the vibratory
tumble
for
a day, and they are all done. The parts are 304 SS cutting from
1/2"
thick plate. Most places I have seen, you e-mail them a DXF or
DWG
file, and then they load the machine and the drawing and go off
and
do
something else.
A Mach 1 jet of water loaded with garnet abrasive does not seem
to
care much what the anneal condition of the metal is, and the nice
thing is that unlike torch or plasma, no annealing happens at the
cut.
It punches its own starting holes, too.