After 13 years of Parametric 3D, my opinion...

Look up 6-axis mill on Google and you will have any choice...we tend to
use Mori-Seiki or other Japanese machines, for obvious reasons.

UG to G-code is a function of the template to generate the actual
code...you should know this.

Your wrong about the blades, they are not cast but forged...big
difference. Forged stock is more stable against thermal transients,
vibration and high inertia. This is important when avoiding the
dreaded Catastrophic Turbine Failures(CTF), although I like to see the
after-effects when all the dust settles, from an engineers point of
view only.

Jet turbines and stationary power turbines are night and day, they just
share the same open cycle concept.

Jet turbines are made as light as possible with every inch being
ultrasonic tested for imperfections in the grain, unless you don't mind
a CTF at 40,000 feet. Stationary power turbines, we designed to be
heavy and stable against primary and secondary resonating
frequencies...mass damping was our friend.

The blades on our steam turbines at the low pressure stage L-0(the
longest ones at the end) were 5 feet long, so CNC 6-axis milling was
the only way to get them consistent.

I've made and assembles many-a-turbines, steam and gas. 6-axis milling
is not science fiction.

Class dismissed.

WV

 

Class dismissed.

No, please, keep going. This is the most interesting stuff to hit the ng
in a while and we casual observers may actually learn something.

 

And the *patterns* used to produce the castings are made... from...
expanded polystyrene cut with hot wire...? <g>

 

Oops. Scratch that. The dies used to forge the blades were machined...
how? <g>

 

Nope.
Lost wax process using ceramic shells last I knew.
Very fragile indeed.

I don't know how they cast the wax though.

 

Such turbine blades are not forged.

Kind of hard to forge hollow stuff (and they are
hollow).

Here's a section of what might be one:
http://dora.eeap.cwru.edu/camlem/turbine.jpg

See all the holes:
http://www.tech.purdue.edu/at/Courses/AEML/powerplantimages/fig65aircooledturbine.jpg
Those are for cooling air to come out of to cool the blade's
surface in operation.
http://www.aoxj32.dsl.pipex.com/NewFiles/HTWTurbines.html

"the temperature in the turbine section is often higher than the
melting point of the turbine blade material"

CFD model of similar:
http://hpcc.engin.umich.edu/CFD/research/gifs/greg_blade.gif


In addition, the really good ones are single-crystal.
They have to be "grown".
http://www.aoxj32.dsl.pipex.com/NewFiles/HTWturb2.html


On machining them ... here's old blurb ....
http://www.findarticles.com/p/articles/mi_m3MKT/is_v93/ai_3722664
(Someone loves ads <G>.)

Note the 12 axes bits.

HTH

 

It's molded. Lot's of loose pieces.

 

I sort of know that but it's been a long time.
We molded some of the soft foam shiping packages
that MISCO used in house to move the wax bits
about, each nested in it's own gentle foam shape.
Never saw the bits made though.

 

www.jarvisairfoil.com

No seats of SolidWorks.

jon

 

Not obvious.
And 5 axes in single-spindle milling is the maximum that is
determinate (tool to work) unless you want to claim spindle
orientation.

Some machines do indeed have more axes ... mostly
for positioning for reach or rigidity. But those are rarely
simultaneous axes andmust generally be
used (if simultaneous) either in 1/T or in a parametric
mode ... and I doubt that driving a sixth axis for your
needs in this manner would be very advantageous.

And the sixth axis ....?

IIRC My post clearly assumed jet turbines.

You have similar issues for both classes of jet turbines.
Not the same ones for steam or water power turbines..

So yours are indeed steam, not jet or aerospace.
Please note my original clear comment: "(Applies to aerospace jet
engines.) "

Perhaps beginning ....

 

IF true, so what?

 

Actually, IIRC, the old MDF UG posts would have had a bit
of trouble with parallel axes machines though the AI (now
Software Magic "Intellipost" AFAIK) or the ICAM posts
would have been capable ....... once you knew how you
wanted to do things.

How are you driving/programming that extra parallel
(I assume) axis?

 

For some odd reason I thought that, for water or steam, the
correct term is "bucket" <G>.
Steam buckets, ....

 

You are right Cliff, the old term for the blade is a bucket as that is
what they resembled many moons ago when they actually looked like a
buckets spinning on a wheel after the steam nozzle blew what is now
classified as low-grade or wet steam.

Imagine a weather vane with a garden-hose type nozzle blasting into the
buckets as they spin.

In between each stage of steam turbine 'blades' are stationary
diaphragms with pieces of airfoils propery configured and they are
called...nozzles!

Even the new japanese drawings use the Kanji symbol 'bucket' for the
blade portion on the rotor and use the kanji symbol 'nozzle' for the
stationary diaphragms.

WV

 

I'll guess the die was roughed, then heat treated, normalized and
finished with EDM, to get the highest accuracy on the contours.

Bo

 

Probably explains why, when you said "turbine blade" ..... <G>.
Even thouugh I covered myself with the bits in the "( ...)"

Back to more interestiing stuff .... what features in UG
are of utmost advanage to you? Skip the NC stuff and the
straight modeling stuff ... so many systems can do that.

Any chance that "Arbitrary Surface Flank Milling"
(ASFM) is in use?

[Wu, C. Y., 1995, "Arbitrary Surface Flank Milling of Fan,
Compressor, and Impeller Blades," ASME Journal of Engineering for Gas
Turbine and Power, Vol. 117, pp. 534-539.]

(Feed jb enough new buzzwords & his head explodes <G>.)

Are most of your surfaces ruled or mostly nondevelopable?

(NOTE: Crossposted to AMC due to subject matter.)

 

For such applications some firms use a CMM or
something to measure the deviations of the parts
produced/formed/stamped to adjust their die
designs in an attempt to produce good parts early
on in the cycle (and then remachine the dies).
Some can make predictions for the first design ...

 

Gee ..... then why is western1812 at hotmail.com
posting interesting SW related things here?
Clearly they know ar more about it than you do.

 

Ahhh, Jon, you are hopeless.

If you spend half your energy trying to better yourself and your
modelling skills as you do committing libel against Solidworks corp,
you would be a better person.

In the turbine industry, the majority of OEM's use Unigraphics.
However, there is a shift to middle ground modellers like SolidEdge and
Solidworks, due to their power to cost ratio.

You must be the only member of the VX self-help/support group because
we seem to see your signature in the least helpful places.

Western Voice.

 

This seems slightly odd as neither has really good associative
CAM capabilities AFAIK.
I suspect larger firms may get decent quantity discounts too.
In addition, UG's licenses can "float" on the network, possibly
requiring fewer of them or module licenses.

Another possible problem is stability and data retention
& migration. At any time you may need to use 20 year
old data .... IMHO. Not that the UG data is yet that old,
probably <g>.

There are also some advanced "automation" features in UG
that I suspect are lacking in the others, among other things.