dear all

I'm going to create a ring with special criteria
some pictures of it can be seen he

http://www.comfx.com/v.php?d=965320
http://www.comfx.com/v.php?d=915997
http://www.comfx.com/v.php?d=917818
http://www.comfx.com/v.php?d=415042

in fact its a half ring with an outer diameter of about 1900 mm, its
shape is some how difficult in some aspects :
- as shown in attached pictures a portion of structure is just an easy
cylinder form but the other portion is conical shaped
- it must be seamless, coldworked and made from stainless steel sheet
- thickness of the sheet is 15 mm
- it must be produced with a good telorance ( the bend shape must b
axact)

my questions are :
which forming process is the best for it?(rolling , spinning , any
other forming process? these are just my guesses )
can it be formed in a full ring and then splited into two halves? or
residual stresses would not let me do something like this even if I
anneal it , and I should form it in a half ring from the begining?

can anybody provide me some information?
any kind of information or sugestion would be precious.
thanks in advance for your care
best regards,
Shantia

The easiest way to do this is in a good sized roll bender with special
dies. Roll a full ring, weld the end together, continue rolling to get
the thing round and the angle fully formed. Cut it apart into 2
completed units.

Most any good structural steel fabrication facility should have the
roller. Dies would be extra.

shantia wrote:
dear all

I'm going to create a ring with special criteria
some pictures of it can be seen he

http://www.comfx.com/v.php?d=965320
http://www.comfx.com/v.php?d=915997
http://www.comfx.com/v.php?d=917818
http://www.comfx.com/v.php?d=415042

in fact its a half ring with an outer diameter of about 1900 mm, its
shape is some how difficult in some aspects :
- as shown in attached pictures a portion of structure is just an easy
cylinder form but the other portion is conical shaped
- it must be seamless, coldworked and made from stainless steel sheet
- thickness of the sheet is 15 mm
- it must be produced with a good telorance ( the bend shape must b
axact)

my questions are :
which forming process is the best for it?(rolling , spinning , any
other forming process? these are just my guesses )
can it be formed in a full ring and then splited into two halves? or
residual stresses would not let me do something like this even if I
anneal it , and I should form it in a half ring from the begining?

can anybody provide me some information?
any kind of information or sugestion would be precious.
thanks in advance for your care
best regards,
Shantia

"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit of
both -- while you keep that blend radius intact.. And this is stainless! You
can't just roll it. you have to iron it at the same time, and ironing it out
so it doesn't twist is going to be an extreme metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress

"Ed Huntress" wrote in message
...

"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit of
both -- while you keep that blend radius intact.. And this is stainless!
You can't just roll it. you have to iron it at the same time, and ironing
it out so it doesn't twist is going to be an extreme metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress


That 15mm must a typo. If the ring is truly that thick, a blank ring could
be rolled and welded, then turned on a lathe.

"Chas Hurst" wrote in message
. ..

"Ed Huntress" wrote in message
...

"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit
of both -- while you keep that blend radius intact.. And this is
stainless! You can't just roll it. you have to iron it at the same time,
and ironing it out so it doesn't twist is going to be an extreme
metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress


That 15mm must a typo. If the ring is truly that thick, a blank ring could
be rolled and welded, then turned on a lathe.

With a 1900 mm diameter? Even for a VTL, that's a big piece of work, and it
isn't going to be cheap to get it done. The material cost alone --
especially if you roll the cone section, which would have to be cut out of a
pretty large plate of 15 mm stock (assuming it's not a typo) -- would be a
hefty chunk of change -- over $3,000 for that one piece of plate. The stock
for the cylindrical ring will be on the same order. Then there's rolling,
and welding, and turning. That assumes it was done by someone who is really
expert and that it doesn't wind up being all distorted out of shape. With
1/2" - plus stainless, that's more than a little problematic, matching a
cone to a cylinder.

As I said, it's all a matter of how much money one has. The total job is
going to run into five figures. This is extreme stuff. I think the first
point here is to see if the OP is aware of what the cost is likely to be.

--
Ed Huntress

"Ed Huntress" wrote in message
...

"Chas Hurst" wrote in message
. ..

"Ed Huntress" wrote in message
...

"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit
of both -- while you keep that blend radius intact.. And this is
stainless! You can't just roll it. you have to iron it at the same time,
and ironing it out so it doesn't twist is going to be an extreme
metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress


That 15mm must a typo. If the ring is truly that thick, a blank ring
could be rolled and welded, then turned on a lathe.

With a 1900 mm diameter? Even for a VTL, that's a big piece of work, and
it isn't going to be cheap to get it done. The material cost alone --
especially if you roll the cone section, which would have to be cut out of
a pretty large plate of 15 mm stock (assuming it's not a typo) -- would be
a hefty chunk of change -- over $3,000 for that one piece of plate. The
stock for the cylindrical ring will be on the same order. Then there's
rolling, and welding, and turning. That assumes it was done by someone who
is really expert and that it doesn't wind up being all distorted out of
shape. With 1/2" - plus stainless, that's more than a little problematic,
matching a cone to a cylinder.

As I said, it's all a matter of how much money one has. The total job is
going to run into five figures. This is extreme stuff. I think the first
point here is to see if the OP is aware of what the cost is likely to be.

--
Ed Huntress

I'd didn't say it would be cheap.
There are companies that specialize in rings and one this size is would be
no problem at all. I think the whole ring could be made from one piece and
turned on a vertical lathe, eliminating welding.

On Jan 5, 5:12*pm, "Ed Huntress" wrote:


As I said, it's all a matter of how much money one has. The total job is
going to run into five figures. This is extreme stuff. I think the first
point here is to see if the OP is aware of what the cost is likely to be.

--
Ed Huntress

It's especially inspiring that the OP doesn't seem to know how to make
such a part, nor does he have any actual tolerance.

A part like this would be *very* difficult to measure without the use
of a CMM. Application-based gauging would be important, especially
when the customer says "no" and the builder says "yes". A good
description of the part's function would be nearly a requirement to
avoid shenanigans.

Regards,

Robin

These guys are somewhat local to me. IIRC, they have a suitable roller.
http://www.bendtec.com/architec.html

I'm inclined to believe the OP is real on the thickness, the drawings
show a pretty hefty thickness in relation to the width. The blank would
be a 20' piece of 5/8"x 8"(?) 304. Calculated weight would be 336
pounds. I haven't priced stainless lately, not calibrated on that one.
I'd certainly hope to get it for less that $5 a pound, that would put
the piece under $2000.

My biggest concern is the OP may think that a fabricated piece will hold
the same tolerances as a machined piece. BTDT, had a very unhappy customer.


Ed Huntress wrote:
"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit of
both -- while you keep that blend radius intact.. And this is stainless! You
can't just roll it. you have to iron it at the same time, and ironing it out
so it doesn't twist is going to be an extreme metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress

"RoyJ" wrote in message
...
These guys are somewhat local to me. IIRC, they have a suitable roller.
http://www.bendtec.com/architec.html

I'm inclined to believe the OP is real on the thickness, the drawings show
a pretty hefty thickness in relation to the width. The blank would be a
20' piece of 5/8"x 8"(?) 304. Calculated weight would be 336 pounds. I
haven't priced stainless lately, not calibrated on that one. I'd certainly
hope to get it for less that $5 a pound, that would put the piece under
$2000.

My biggest concern is the OP may think that a fabricated piece will hold
the same tolerances as a machined piece. BTDT, had a very unhappy
customer.

I agree a fabrication would present problems.
It's possible a casting could be made. A quick search just dug up a few
companies that have the capability.

Ed Huntress wrote:
"RoyJ" wrote in message
...
The easiest way to do this is in a good sized roll bender...

"Good sized"? Roy, 15mm material thickness is over 0.59". The cone is
attached to the straight cylinder, so one edge is going to have to be
stretched or the other is going to have to be shrunk -- or a little bit
of both -- while you keep that blend radius intact.. And this is
stainless! You can't just roll it. you have to iron it at the same time,
and ironing it out so it doesn't twist is going to be an extreme
metalworking job.

Unless you have access to the machines used for making Saturn V rocket
nozzles, I think there is a problem here. d8-) The forces involved are
astronomical.

--
Ed Huntress

"RoyJ" wrote in message
...
These guys are somewhat local to me. IIRC, they have a suitable roller.
http://www.bendtec.com/architec.html

I'm inclined to believe the OP is real on the thickness, the drawings show
a pretty hefty thickness in relation to the width. The blank would be a
20' piece of 5/8"x 8"(?) 304. Calculated weight would be 336 pounds. I
haven't priced stainless lately, not calibrated on that one. I'd certainly
hope to get it for less that $5 a pound, that would put the piece under
$2000.

My biggest concern is the OP may think that a fabricated piece will hold
the same tolerances as a machined piece. BTDT, had a very unhappy
customer.

I can't see how you'd do the angle (cone) and the cylinder (flat) on a pipe
bender, Roy, but I'll be interested to hear if they'll give a quote, and
what it is.

--
Ed Huntress

Operative word is 'roller'

A quick google brought up this mfg: The largest unit on this page
http://www.wikco.com/rbndr.html
will easily handle this cross section. Most of these roll benders will
operate in either the vertical position (shown) or horizontal position
(better for this project) There is a max size calculator at the bottom
of the page.

You would need to make one male roller and two female rollers. These
would be some pretty massive chunks of tool steel, probably 8" in
diameter by 9" long (1/2" flanges to contain the 8" material on each
side). The rollers are easy to make: turn on a lathe, bore the center
hole, broach the keyway, heat treat.

The OP's shape would require that one side would need to shrink, hard to
do in a roller. In real life, multiple passes through the roller will
likely stretch the outside some. That makes the final diameter a bit of
a guess.

Final process would probably be: roll with flat roller (or in a big slip
roll), weld the ends together, start forming the angle leg of the
ring. I'd expect that you would need to cut out a section and reweld to
get the diameter just right. This is not an easy part to make but I'd
hope to get one finished ring out per 8 hour shift with a team of two.

BTW: the equipment in the shop that I interned in (just down the block
from BendTec) had an 8'x1" shear and an 8' slip roll that was quite
happy with 8' x26' of 3/8" plate, used to make tanks and industrial
furnace duct work. Lots of similar places around the country.

Ed Huntress wrote:
"RoyJ" wrote in message
...
These guys are somewhat local to me. IIRC, they have a suitable roller.
http://www.bendtec.com/architec.html

I'm inclined to believe the OP is real on the thickness, the drawings show
a pretty hefty thickness in relation to the width. The blank would be a
20' piece of 5/8"x 8"(?) 304. Calculated weight would be 336 pounds. I
haven't priced stainless lately, not calibrated on that one. I'd certainly
hope to get it for less that $5 a pound, that would put the piece under
$2000.

My biggest concern is the OP may think that a fabricated piece will hold
the same tolerances as a machined piece. BTDT, had a very unhappy
customer.

I can't see how you'd do the angle (cone) and the cylinder (flat) on a pipe
bender, Roy, but I'll be interested to hear if they'll give a quote, and
what it is.

--
Ed Huntress

"shantia" wrote in message
...
dear all

I'm going to create a ring with special criteria
some pictures of it can be seen he

http://www.comfx.com/v.php?d=965320
http://www.comfx.com/v.php?d=915997
http://www.comfx.com/v.php?d=917818
http://www.comfx.com/v.php?d=415042

in fact its a half ring with an outer diameter of about 1900 mm, its
shape is some how difficult in some aspects :
- as shown in attached pictures a portion of structure is just an easy
cylinder form but the other portion is conical shaped
- it must be seamless, coldworked and made from stainless steel sheet
- thickness of the sheet is 15 mm
- it must be produced with a good telorance ( the bend shape must b
axact)

my questions are :
which forming process is the best for it?(rolling , spinning , any
other forming process? these are just my guesses )
can it be formed in a full ring and then splited into two halves? or
residual stresses would not let me do something like this even if I
anneal it , and I should form it in a half ring from the begining?

can anybody provide me some information?
any kind of information or sugestion would be precious.

How much money do you have? You're going to need a bundle.

--
Ed Huntress

I think a part like this would cost a LOT more than $1500 per part.

The way it would probably be done in industry these days is to get
somebody like Scot Forge
http://www.scotforge.com/
to roll forge you a blank.
This would give you an oversize ring, without welds, that had the
grain forged continuosly around the circumference for strength.

Then, you send it to a machine shop that has a good sized VTL or VBM.

I was in a factory in Italy a couple of years ago that built big
machines, and they were making similar sized and shaped parts in this
way- a roll forged ring, machined on a vertical lathe about the size
of a two car garage. They had a whole row of these machines at work.

The material cost is one thing- but the real cost is in the equipment
capable of doing this size of work to these tolerances, and the
experience and infrastructure to support these machines.

This aint no garage job.

Like I said- If I seriously needed one of these, I would pick the
brains of companies that do it everyday, as job shops, and I would
start with Scot.

"Ries" wrote in message
...

I think a part like this would cost a LOT more than $1500 per part.

Shantia said "$16,000 is just fine," so it should be OK, if he's making more
than one. He did mention that making a full ring and splitting it would be
OK, too. However, he said at one early point that it had to be cold-formed,
while this process is hot-forming. But he may have been thinking only about
casting as the alternative.


The way it would probably be done in industry these days is to get
somebody like Scot Forge
http://www.scotforge.com/
to roll forge you a blank.

I agree -- especially if he's going to make more than a couple of them. The
first one will cost a bundle.

This would give you an oversize ring, without welds, that had the
grain forged continuosly around the circumference for strength.

Then, you send it to a machine shop that has a good sized VTL or VBM.

I was in a factory in Italy a couple of years ago that built big
machines, and they were making similar sized and shaped parts in this
way- a roll forged ring, machined on a vertical lathe about the size
of a two car garage. They had a whole row of these machines at work.

The material cost is one thing- but the real cost is in the equipment
capable of doing this size of work to these tolerances, and the
experience and infrastructure to support these machines.

This aint no garage job.

Like I said- If I seriously needed one of these, I would pick the
brains of companies that do it everyday, as job shops, and I would
start with Scot.