Subject: Egg drop mechanism
From: "mchalefla@worldnet.att.net"
Date: Thu, 07 Nov 1996 23:39:35 -0500
Does anyone have any idea how I can build a device, whose volume is less
than 400 cubic cm, which can carry an egg through a 10 meter fall, and
land on concrete without breaking the egg? Additionally, the lower the
mass of the device, the better.
Thanks,
Kevin McHale
Subject: X-33 info....help!!
From: hbmen026@huey.csun.edu (manuel magrane)
Date: 8 Nov 1996 00:15:27 GMT
Hello,
I am an engineering student at CSUN, and I am writing a
paper on the DC-X/DC-XA/X-33 reusable rocket prototype, more specifically
on the materials (Al-Li alloy). Does anybody know of any references
whether it be on the internet, books, or magazines I can be pin-pointed
to? I have tried several periodical resources, but they are too skimpy
when it
comes down to specifics. Any information is appreciated! Personal email is
preferred.
Thanks a lot,
--------------------------------------------------------------
\ / Manny Magrane
|\ /| CSUN - SECS Dept. of Mech. Engineering
| \ / | hbmen026@csun1.csun.edu
\ / \/ \ /
\_/ \_/
"Success is more attitude than aptitude."
- Unknown
"If opportunity doesn't knock, build a door."
- Milton Berle
-----------------------------------------------
Subject: Re: Design of pressure housings
From: Charles Coughran
Date: Fri, 08 Nov 1996 01:17:52 -0800
-A.RIZZO wrote:
>
> >> I am looking for design guides on pressure housings to resist external
> >> pressure. We are looking at submersion to 300m of seawater, and would
> >> like to design/ build our own pressure housings for electronics and
> >> computing boards (up to 300mm wide).
> >All the stress formulas you need are in Roark, _Formulas for Stress
> >and Strain_.
> Is elastic stability a cause for concern?
Not generally at these depths with length/diameter ratios and wall
thicknesses that don't scream long, skinny, and thin. Although,
my experience may very well be biasing my perceptions. In any
event, elastic stability is addressed in Roark as well. I also
notice that I made an assumption that the original poster was
talking about conventional cylindrical pressure cases which
was not actually specified.
--
Charles Coughran
ccoughran@ucsd.edu
Subject: Re: Pipe Section Modulus
From: mwcraig
Date: Thu, 07 Nov 1996 21:20:00 +0000
Paul Skoczylas wrote:
>
> Shane Mason wrote:
> >
> > Does anyone out there know the formula to derive the section modulus
> > for pipe? At work, all our benders are rated at section modulus, say
> > 3.5, for schedule 80 steel pipe. Our problem is we deal with a lot of
> > stainless steel, some schedule 160, some T11, T91, etc. and don't know
> > what the section modulus for those are.
> >
>
> Section modulus is a geometric property, so the type of material is not
> important. Section modulus, Z, is equal to the moment of inertia (I)
> about the neutral axis, divided by the maximum distance from the neutral
> axis.
>
> For Schedule 80 pipe, the section modulus is 2.225 in^3 for 3" (NPS)
> pipe, 3.140 in^3 for 3.5" pipe and 4.271 in^3 for 4" pipe. (Regardless
> of the type of steel the pipe is made from.)
>
> -PaulMore commonly "S" is used as the elastic section
modulus. "Z" is usually used to denote the plastic
section modulus.
The one that you are interested in is most likely
"S" which is pi X d^2 X t / 4, where d is the
diameter of the pipe and t is the wall thickness.
matt
Subject: Jobs for Presion Manufacturing Engineers
From: hrd@softrix.com (Softrix, Inc.)
Date: 8 Nov 1996 03:46:27 GMT
Position: Manufacturing Engineers
(Permanent position with a major
client company)
Location: Connecticut
Required Skills: - 4+ years of industry experiemce in
manufacturing involving precision mechanisms,
plastics, and high-volume hand assembly
Desired Skills: - Medical Instrumentation.
Please forward your resume immediately to:
SOFTRIX, Inc. email: hrd@softrix.com
P.O. Box 937 or
Dayton, NJ 08810 Fax : 908-274-0162
We are a well established recruiting and executive search firm
serving candidates and clients throughout the country. Our
clients range from exciting start ups, well established small
to medium sized engineering, computer, telecommunications,
finance and brokerage firms, to high growth Fortune 500
companies. Our massive networking capabilities allow us to
conduct an in-depth search on local, state, regional and
national bases. Please forward your resume to learn more
about the above mentioned exciting opportunity.
Subject: Jobs for Pro-Engineer, Metal, Plastics, Precision Design Engineers
From: hrd@softrix.com (Softrix, Inc.)
Date: 8 Nov 1996 03:54:23 GMT
Position: Mechanical Design Engineers
(Permanent position with a major
client company)
Location: Connecticut
Required Skills: - 3+ years of industry experience in
design involving metals, plastics and small
precision mechanisms.
- Experience with Pro-Engineer
- Experience with Tolerance Study/FEA, PDM
Desired Skills: - Medical Instrumentation.
Please forward your resume immediately to:
SOFTRIX, Inc. email: hrd@softrix.com
P.O. Box 937 or
Dayton, NJ 08810 Fax : 908-274-0162
We are a well established recruiting and executive search firm
serving candidates and clients throughout the country. Our
clients range from exciting start ups, well established small
to medium sized engineering, computer, telecommunications,
to high growth Fortune 500 companies.
Our massive networking capabilities allow us to
conduct an in-depth search on local, state, regional and
national bases. Please forward your resume to learn more
about the above mentioned exciting opportunity.
Subject: Re: Fighting Complexity
From: Kurt Jaeger
Date: Thu, 07 Nov 1996 23:29:42 -0800
Jonathan Priluck wrote:
>
> Hello (good morning?),
>
> It's 4:00 am and I can't sleep becuase this new injection mold
I wanted to talk about in the first place. The real issue is that nobody
> seems to want to *try* the simple solution first. What I want to know is why
> that is?
>
> Best Regards, Jon Priluck
Probably for the same reason that drug companies push high-tech drugs
rather than
natural stuff, no money in it. If an answer is simple enough that anyone
could have
come up with it then maybe you don't need the highly paid technical
people to do it!
So the job requires a complexity to match the credentials of the people
involved in
order to justify their presence on the job.
Also I read an interesting article where the authour was talking about
how,
thoughout our education, the emphasis is on the one "right" answer. If
we
don't get the one "right" answer we are penalized for it, only
perfection is
acceptable. Consequently we learn not consider alternative, acceptable,
or
just "good enought". To wit:
"My granddaddy told me to use my head. I told him I
wanted to pound nails and I was going to use a hammer
instead" -unknown
Sometimes we use our heads to much and fail to set down, grab the hammer
and
get the job done.
Kurt Jaeger
Subject: Re: Flow Discharge Coefficients
From: mwcraig
Date: Thu, 07 Nov 1996 22:50:56 +0000
Tanya DeVoe wrote:
>
> I am looking for an equation or empirical data relating flow discharge
> coefficient and temperature and also an equation relating discharge
> coefficient and viscosity. I am particularly interested in this
> information for various aviation fuels (for example: JP-8, Jet A, Jet
> A-1, JP-5, JP-4, Jet B). Any help would be appreciated. Thanks.
> --
> ======================================================================
> Tanya DeVoe
> Loads and Dynamics Group phone: (912) 965-3809
> Gulfstream Aerospace Corp. fax: (912) 965-4812
> Savannah, GA - USA email: tdevoe@gulfaero.com
> ======================================================================
The American Petroleum Institute (API) publishes viscosity and density
tables vs temperature for these fluids, I think.
Once you have that you can get discharge coefficients from velocity and
Reynolds number only. I think ASME publishes coefficients for use with
standard geometries of orifices.
If you aren't using a standard geometry of orifice, then a text or
handbook of fluids is your best bet without doing your own flow tests.
Try Crane's "Flow of Fluids Through Pipe, Valves, and Fittings"
There are near-real-time flow computers made by Daniel Industries (?)
that can compute flow through standard orifice set-ups very accurately.
They use differential pressure and temperature transducers and can be
preprogrammed with density and viscostiy vs temperature equations/tables
for various fluids. They then iterate using estimated velocity and the
ASME or API flow coefficients until the flow is calculated, displaying a
flow rate every second or so. The will also integrate to give total
volume delivered. This might not be what you're looking for, though.
Finally, recall that if the Reynolds number is high enough for all
operating temperatures, flowrates, and the given geometry of
restriction, then the coefficient of discharge is nearly constant. As a
rule of thumb, if Re > 10,000 based on orifice diameter, and the area
ratio of the restriction to the main flow is less than about 1:25, then
Cd converges to about 0.61.
-matt
Subject: Re: Egg drop mechanism
From: Chad English
Date: Thu, 07 Nov 1996 21:00:56 -0500
mchalefla@worldnet.att.net wrote:
>
> Does anyone have any idea how I can build a device, whose volume is less
> than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> land on concrete without breaking the egg? Additionally, the lower the
> mass of the device, the better.
>
> Thanks,
> Kevin McHale
How about an egg parachute. Considering the thin-ness of the material
it will easily be under 400 cubic cm, and lightweight.
--
("`-''-/").___..--''"`-._
`6_ 6 ) `-. ( ).`-.__.`) Chad English
(_Y_.)' ._ ) `._ `. ``-..-' cenglish@mae.carleton.ca
_..`--'_..-_/ /--'_.' ,' http://www.mae.carleton.ca/~cenglish
(il).-'' (li).' ((!.-'
Subject: Re: Soda fizz
From: klwasson@aol.com
Date: 8 Nov 1996 11:48:42 GMT
> Subject: Soda fizz
>From: handreas@msmail4.hac.com (Andreas, Harry A)
>Date: 1 Nov 1996 22:58:42 GMT
>Message-ID:
>
>Everyone knows that if you pour soda [that's pop for you mid-westerners]
into a glass it fizzes up for a while [beer, too].
>But after the foam goes away, if you pour some more in, it rarely fizzes
up again, or at least not much.
>This bugged me for some time because I don't like really fizzy drinks and
I try to get rid of most of the fizz.
>I believe that I know the answer as to why it will not fizz up much the
second time around, but was surprised to find that most, nay, all, of my
engineering colleagues could not come up with the answer.
>So send me an e-mail if you know, or think you know, or don't give a rats
ass and just want the answer.
>
>Harry
Here is a related phenomenon. Take a half-full bottle of beer and slam it
real hard on its top by the bottom of a second bottle of beer, so hard
that you almost think you might crack the glass. The beer will foam up so
much it will overflow the top, much more so than if you had shook the
bottle of beer for ten minutes. Why?
Subject: Re: Egg drop mechanism
From: "Alan K. Gideon"
Date: Fri, 08 Nov 1996 07:35:54 -0500
Alan K. Gideon wrote:
>
> mchalefla@worldnet.att.net wrote:
> >
> > Does anyone have any idea how I can build a device, whose volume is less
> > than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> > land on concrete without breaking the egg? Additionally, the lower the
> > mass of the device, the better.
> >
> > Thanks,
> > Kevin McHale
>
> Yes
>
> --
> Alan K. Gideon, P.E. | Naval Architect & Marine Engineer
> | akgideon@mindspring.com
Sorry about the apparently smart-mouth answer. It's just that I always
avoided actually doing my children's homework for them.
--
Alan K. Gideon, P.E. | Naval Architect & Marine Engineer
| akgideon@mindspring.com
Subject: Re: Coefficients of Friction for Tire on Roadway
From: bk@sydney.DIALix.oz.au (Bruno Karlin)
Date: 8 Nov 1996 21:57:33 +1100
jason graklanoff (jgrakla@siue.edu) wrote:
:
: I am looking for static and kinetic coefficients of friction for
: automotive/truck tires on dry, wet, and dirty roadways. Need not be specific
: to any particular tire model; typical numbers are just fine. Can anyone help
: me out?
:
: Jason Graklanoff
: jgrakla@siue.edu
Hello Jason,
here's some quick and dirty numbers.
A very *average* vehicle will pull about 0.6-0.7 G's in a corner.
That makes a coefficient of static friction of 0.6-0.7.
Sliding/skidding will remove 15-20% of that.
Wet roads use 0.3-0.4, and sliding in the wet is considered either
a hoot or a health hazard and beyond the scope of this diatribe.
Regards,
--
Bruno Karlin, BE(Mech) ~~~Vibration Analysis & Monitoring~~~
bk@sydney.dialix.oz.au Busn +612 95622404 Fax +612 95622451 ()()()
Mail: ADI Ltd, Box 4W Garden Island, SYDNEY 2000, AUSTRALIA ()()
. . . my opinions, their mailbox!
Subject: Re: (no subject)
From: David Wood
Date: Fri, 08 Nov 1996 15:31:41 GMT
Don
> post, signal flags, morse code, etc.) Thanks for any help you can
^^^^^^^^^^^^
I sent you a reply yesturday, but you weren't on the hill at the time
:-)
--
David Wood d.wood@thermoteknix.co.uk postmaster@thermoteknix.co.uk
I try to live one day at a time, but lately several days have attacked
me at once.
(Note that my return address is intentionally invalid in order
to foil electronic mailing list generation software.)
Subject: Re: 3D Beam element (NISA software has these elements)
From: hei@pop.nlci.com (Hunkler Engineering)
Date: 8 Nov 1996 15:52:04 GMT
In article <9611052000192791@engineers.com>, bill.weitze@engineers.com
says...
>
>MB>I am looking for some source code that will compute the
>MB>stiffness matrix for a full 3D beam finite element.
>
>
NISA family of programs has 3-D beam elements.
NISA family of FEA software is one of the most comprehensive
capabilities in FEA. It can do linear, non linear, dynamics, heat
transfer, magnetics, fatigue, composites, compressible and
in-compressible fluids, optimization, etc. etc.
e-mail me for more info.
Samir Shah
Hunckler Engineering, Inc.
(317) 474-1300
hei@pop.nlci.com
Subject: Re: Egg drop mechanism
From: "Ian O'Connell."
Date: 8 Nov 1996 06:32:16 GMT
mchalefla@worldnet.att.net wrote in article
<3282B987.6846@worldnet.att.net>...
> Does anyone have any idea how I can build a device, whose volume is less
> than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> land on concrete without breaking the egg? Additionally, the lower the
> mass of the device, the better.
>
> Thanks,
> Kevin McHale
>
What about a perforated concrete base with an air jet-stream, sufficiently
strong to de-accelerate to zero velocity at impact! (the base portion
would obviously have to be enclosed in a tubular section)
Ian O'Connell
ianoco@icon.co.za
Subject: Re: Egg drop mechanism
From: Tom_Austin
Date: Fri, 08 Nov 1996 08:32:45 -0800
Alan K. Gideon wrote:
>
> mchalefla@worldnet.att.net wrote:
> >
> > Does anyone have any idea how I can build a device, whose volume is less
> > than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> > land on concrete without breaking the egg? Additionally, the lower the
> > mass of the device, the better.
> >
> > Thanks,
> > Kevin McHale
>
> Yes
>
> --
> Alan K. Gideon, P.E. | Naval Architect & Marine Engineer
> | akgideon@mindspring.com
--
You crack me up! let him do his own class project!
Tom Austin
Subject: Anhydrous Ammonia!
From: rick@rdumais.slip.indy.net (Rick Dumais)
Date: 8 Nov 96 18:12:54 GMT
***** Ammonia Refrigeration *****
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in general, we have a WEBSITE you need to check out!!
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Ammonia Refrigeration Technicians Association
http://rdumais.slip.indy.net/
Click on address above and browse our site!
Test your refrigeration knowledge, become an ARTA member, register your
refrigeration skills, Do an ARTA database search, get technical information,
Buy safety aids, Ask a refrigeration question etc. !!!Check it out today!!!
Note: This site is not always connected to the Net, Try again later if you
connot connect the first time. Thanks "System Administrator".
-------------------------------------------------------------------------------
Subject: Re: Egg drop mechanism
From: "mchalefla@worldnet.att.net"
Date: Fri, 08 Nov 1996 22:56:11 -0500
mchalefla@worldnet.att.net wrote:
>
> Does anyone have any idea how I can build a device, whose volume is less
> than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> land on concrete without breaking the egg? Additionally, the lower the
> mass of the device, the better.
>
> Thanks,
> Kevin McHale
Let's clarify something, Alan Gideon, Tom Austin and Thomas Wynsen...
Who do you punks think that you are, criticizing me in such a way?
Perhaps it's because I am new to USENET that I have taken offense to the
replies to my simple query. Or perhaps it's because I take any
criticims of my own intelligence very seriously. However, if you wish
to preach to me the importance of doing this project on my own, then you
obviously do not wish to offer advice, which is all that I asked of you.
Did I ask for a sermon on the benefits of doing my homework myself? I
think not. Next time, don't waste your typing time or my reading time
for your useless and pointless comments.
Kevin
Subject: Re: Egg drop mechanism
From: "James W. Baker"
Date: Fri, 08 Nov 1996 15:53:03 -0500
Tom_Austin wrote:
>
> Alan K. Gideon wrote:
> >
> > mchalefla@worldnet.att.net wrote:
> > >
> > > Does anyone have any idea how I can build a device, whose volume is less
> > > than 400 cubic cm, which can carry an egg through a 10 meter fall, and
> > > land on concrete without breaking the egg? Additionally, the lower the
> > > mass of the device, the better.
> > >
> > > Thanks,
> > > Kevin McHale
> >
> > Yes
> >
> > --
> > Alan K. Gideon, P.E. | Naval Architect & Marine Engineer
> > | akgideon@mindspring.com
>
> --
> You crack me up! let him do his own class project!
>
> Tom Austin
Kevin,
I guess you can see that most of us MEs had to do this or a similar
class project (in fact I was an advisor and had a group of 16-18 year
old engineering explorers do it). There are many ideas for solving this
problem, each to work within a specific set of rules, but I'm afraid
you'll have to think of them yourself.
I'll tell you about one in my class. The egg was placed in the middle
of a big plastic trash can, with a lid, that was filled with shaving
cream. I don't recall if the egg survived, but it made for a good show
on impact.
Good luck,
Jim Baker