On Wed, 10 Jun 2015 16:15:24 -0700 (PDT), jon_banquer
The Airbus A350 XWB has more 3D-printed elements than any
other commercial passenger jet. The roughly 1,000 parts were
created in partnership with Stratasys, the additive
Stratasys reportedly used an ULTEM 9085 resin, which is
certified to an Airbus material specification, to fabricate
each part on an FDM 3D printer. The process melted the resin
and extruded it layer by layer until entire parts were
fabricated. This method produces parts that are lighter in
weight and strong, as well as being flame, smoke and
On Thu, 11 Jun 2015 13:08:18 -0500, F. George McDuffee
In aerospace, AM is producing turbine engine compressor blades, and
some driven turbine blades, from a chrome-cobalt superalloy. Other
parts are being made from maraging steel, precipitation-hardening
stainless (17-4 PH and others), and several grades of aluminum and
titanium. These are 100% dense; they're not sintered parts.
If you want a quick rundown of the metals they can print, the article
I linked to earlier gives the highlights. It just applies to the
laser-melting process. There are some other metals that are included
in the electron-beam-melting and other AM processes:
The difficult part is applying AM to fast-quenching, heat-treatable
steels and other heat-treatable metals. That's where the research is
being applied now.
Rather than slamming 3d printing, how about an assist in
designing/processing the parts for printing?
Most of the posters have a knowledge of cad, and can create
a 3d wire form of an object. and have access to a cad
What hints would you care to give to the group for creating
3d surfaces from a wire frame model, particularly compound
curved surfaces and inside corner radii, so these are
"manifold" and can be processed through a "slicer" program
to generate the FFF g-code file for 3d printing?
Do you know of any [free] VBA or AutoLISP macros or add-ons
to "skin" a DXF/IGES wire frame?
On Wednesday, June 10, 2015 at 7:15:28 PM UTC-4, jon_banquer wrote:
I dunno Jon, I read your Linkedin page, and I didn't see any "admissions" f
rom anyone. I saw a discussion of the limitations of poorly thought out 3d
prints which produce parts that can't be machined efficiently. The same cou
ld easily be said about ANY poorly designed part regardless of the techniqu
That said, I spent the day yesterday at the Javits Center in NY attending t
he MD&M show http://mdmeast.mddionline.com . I spoke with plenty of manufac
turers who use 3D printers to generate mold patterns, proofs of concept and
finished products. These are real companies producing real products.
So, perhaps 3d printing has been overhyped in your world, but it certainly
has not been in the world of medical devices - the surface is only beginnin
g to be scratched.
On Wed, 10 Jun 2015 18:00:18 -0700 (PDT), rangerssuck
You aren't surprised about that, are you? d8-)
"Design for production" has been a mantra in production for at least
50 years. Caterpillar was a pioneer, in the early '70s, at taking
their new design engineers and putting them on the shop floor for six
months before they'd let them design anything. My FIL was part of that
program at Cat's Aurora plant, teaching those new engineers how things
are actually made. It really paid off for Caterpillar, and other large
manufacturers picked up on the program. But not everyone caught on.
I took a look at the "admissions" comments Bonker's apparently is
referring to in the subject line, and it's all about one small aspect
of AM -- prototyping for conventional machining -- that isn't even
where the action is in AM anymore. Since they're involved in machining
and CAM, it's no surprise that's where their attention and interest
lies, but the real interest in AM has moved on.
Tooling, like the AM plastic fixturing, clamps, and gaging tools at
Volvo Trucks, is attracting a lot of interest. And scroll down to look
at the colored drawing of this mold insert:
That thing is made of maraging steel, and it cycles 40% faster than a
conventionally milled or EDMed mold, because of those cooling
passages. They're a snap with AM, but impossible to machine in a
single piece. The company is doing a land-office business in making
The irony here is that one or two of JB's commentators are bitching
that designers are 3D printing things that can't be machined (what
else is new? They've been drawing things that can't be machined for
eons.). But that mold cavity, and the fuel nozzles the turbine-engine
manufacturers are making with AM, are made with AM specifically
because they CAN'T be conventionally machined.
How many such parts will be uncovered is hard to say, but AM already
is moving past that stage, at least in terms of where the incentives
are driving the machine builders. The US Army, Navy and Air Force, and
domestic aircraft manufacturers, are using AM right now as a way to
make on-demand replacement parts for airplanes and military equipment.
That market potentially is huge, extended to civilian uses beyond
This "hype" subject came up months ago, and I pointed out at the time
that there certainly is a lot of hype about 3D printing in the
consumer press and in some segments of the trade press. It's possible
that the hype has penetrated the design and management departments of
some manufacturers. But the people who know what they're doing aren't
the ones who are hyping it (except in press releases). They're
building machines that are actually making parts, in both plastic and
metal, for a variety of industries. And the market is growing pretty
fast overall, even if it's a little herky-jerky. If the price of
full-melt metal AM systems comes down, there won't be any question
I went through that myself as a production floor assembler and then a
pencil-and-paper draftsman at a maker of custom production test
equipment. They had electrical and mechanical engineers but the
project leader position I was working toward had to be a generalist
who knew some of both plus HVAC and industrial wiring and could use
The subject of the lesson was the design of structural sheetmetal to
be made on a press brake and Strippit punch. I didn't have to become
an expert at operating the machines, only understand the tolerances
they were capable of and the necessary sequence of operations, such as
punch ALL the holes and corner notches, THEN do the bending, and try
to minimize the inevitable match-drilling at final assembly.
As you say, not everyone can correctly imagine how the three
dimensional part will be made, and that includes some very smart
electrical engineers. A Physics professor I knew socially told me he
had switched majors from Chemistry because he couldn't visualize
molecular structures rotating and vibrating in three dimensions.
I was stuck for a while on how to accurately locate the bearing
press-out holes on the wheels I'm making. My mill doesn't have enough
vertical clearance to index the blanks in a chuck. I finally chucked
the disks in the milling vise and located the #10 (~3/16") tapped
holes as close as possible to both sides of the OD of the bearing
recess by feeling the clearance of a #2 drill/countersink to the wall
So I still design features I don't know how to make, assuming I'll
figure out something later and change the drawing to match.
Two opposed holes were adequate when the first bearing was initially
pressed fairly hard into an 0.0004" interference fit. I could turn the
cap screws 1/6th turn alternately to press it out. The final fit is
close enough to turn the screws simultaneously with my fingers. The
electric trolley hoist will see so little use that wear if the
bearings shift isn't an issue. Mainly it will keep heavy logs away
from my feet. The HF manual I-beam trolley's bearings are quite loose
on their axles.
I'm trying to accustom myself to progressive (no-line, varifocal)
eyeglasses I bought yesterday. They shift continuously from
nearsightness correction at the top to slight magnification at the
bottom, with the result that only a few lines of text on the screen
are clear, though the sharp focus distance varies from 12" at the
bottom to seeing the bright stars Arcturus and Spica nearly as points
instead of blobs at the top. Also I can't use the larger monitors on
the shelf above the laptops without tilting my head up uncomfortably
or leaning back too far to type. Last night I detailed the CAD drawing
of the wheel axle on the 15" laptop screen, easily, instead of on the
22" display above it that I use without glasses.
I lost my previous company-issue glasses at a volunteer construction
project a few weeks ago after taking them off to start a balky
generator. They were probably trampled into the dirt, run over by a
skid-steer, then buried under tons of sand. Providentially I kept an
older pair in the car.
I wore progressives for six years. I couldn't stand them while using
the computer. Mine were supposed to be the best Variluxes made. ($880
including frames -- thank God I had multiple insurance policies! I
paid $20.) Still, the narrow focus field made driving a little scary,
and the up-and-down head motion took a while to get used to.
Over this past winter I had cataract operations on both eyes. At the
end, the doctor said "You don't need glasses anymore." And he was
right. Except for reading. He told me to get some drug-store
magnifiers, which I did.
I liked progressives for one thing: shopping at the supermarket. <g> I
saved mine just for that one use.
Good luck with them. Some people have no trouble adjusting. It took me
>I lost my previous company-issue glasses at a volunteer construction
I loved them immediately for general use but they aren't so good for
the long, close work that I can do without glasses. I'll have to watch
out for situations where I might take them off without having a safe
place to store them, like that construction site. They aren't as bad
for that as the company-issue bifocals I lost whose lower section
wasn't really sharp any useful working distance. The eye doctor lacked
the equipment to test near vision so I asked that they at least make
the ground clear enough that I wouldn't trip, and suggested half the
correction of the top.
At home I have a deep bathtub soap basket on the wall at the foot of
the basement stairs to safely store eyeglasses, since I wear a
headband magnifier or safety glasses with reading sections in the
shop. There's a pair at each machine.
The extensive trilingual safety warnings on the bag take up so much
space that they are in a tiny font I can't read without opening the
bag and putting on the glasses. That's like Taylor Swift's remark
about the illogic of scissors that come in a blister package you can't
open without -- scissors!
LOTS of people can't think in 3D, so that doesn't surprise me at all.
Isn't that the way it's always done? (see TBD dwg for reference)
To lower rolling resistance, I'm sure.
Good luck. I nearly nuked a pair I tried a decade ago, but settled
for flowing plasma at both the optometrist and his assbite office
manager instead. After two weeks of severe headaches and a couple
near misses in the truck, I'd had it. They never told me that 80% of
the lens has no correction whatsoever, so my brain was left to handle
translation of my twin astigmatisms on its own. It didn't like that
after several decades of help from real eyeglasses, TYVM.
Condolences. I lost a lens once, when a screw loosened; sucked.
Yes, always keep spares! That's another reason I like buying from
Zenni. An extra pair (stainless framed hi-index bifocals) costs about
$30, so I buy two pair at a time, keeping a pair with the brand new
prescription as a spare each time. My old prescriptions are in a
drawer, the new spares in the truck (now in my BOB) at all times.
Worrying does not take away tomorrow's troubles,
it takes away today's peace. --Lifehack
Only if the ball bearings jam from dirt, which is possible since the
ones they used don't all have seals on the hidden side. They didn't
waste any extra effort making those things. I'm doing a more careful
job for the practice.
How is Zenni to deal with? I got a second version of the prescription
for normal bifocals with reading lenses on the bottom which I think
would be good for driving and better for extended close work. My eyes
are too different for drugstore reading glasses to work well. I
speed-read which requires a wide field of sharp vision.
Indifferent, but that's usually not a problem. Watch your data entry.
I missed seeing a wee minus sign, so my first order was unwearable.
They offer 50% back if you return the order, so it's not an entire
loss. But it takes a month to happen.
With your speed reading, I strongly doubt you'll adapt to the new
progressive lenses, unless the page fits within the scope of the
progression. I'm highly sensitive to distortions, so I couldn't deal
at all. I'd sooner adapt to a bloody fisheye, I think. (Oh, no! Now
Gunner and Pete will think I hate/kill/destroy progressive lenses.
Hmm, maybe on this, they'd finally be right. ;)
Worrying does not take away tomorrow's troubles,
it takes away today's peace. --Lifehack
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