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Jarrett,
A great and admirable undertaking - I wish you
lived/worked locally!
Give us an idea of your design!?
George ( down under)
George, it will do pretty much whatever size you want. 20ft x
44" would require splitting it into two pc's [ the usable length is 18ft
of actual machine travel] but, if that includes the cowl and the rudder, then
it could be done in 1 pc as you'd do those seperatly. Large plugs which have
to be fabricated in more than 1 pc are a little bit more labour intensive, but
can be produced so as to bolt together into 1 usable unit. It's a machined
part so the dimensional sections will fit and match, even if its a complex 3d
shape.
I entered into this venture because I wanted to build my own plane
[of my own design]. I realized that to do this would be a huge undertaking
making all the needed molds, so I decided to get a machine that would do it
for me. It should be able to do plugs and molds which will require very little
[if any] finish work, other than a lite sanding w/ a foam board to take down
any little ridges left by the tooling.
Realizing that others could use the same machine for their own
projects was also a motivating reason to go ahead w/ aquiring it. The actual
operating cost's should be low enough that it would be cheaper to use this
unit over doing a plug yourself [if you value your time @ more than at minimum
wage or so]
I also plan to use it to do complex patterns/cores for Aluminum
casting, but thats a bit farther out into the future.
Jarrett
----- Original Message -----
From: George Lendich <lendich@optusnet.com.au>
Date: Tuesday, January 30, 2007 4:45 pm
Subject: [FlyRotary] Re: New Cowl Contest
> Jarrett,
> Gawd that's massive, even something smaller
would be awesome. It
> would be good, seeing your involved with
Aviation, to get a lot of
> work involving Aviation products.
>
Would your machine be able to handle a light fuselage pattern, say
>
about 20' long, usual 2 person width, say 44"?
> George (down under)
> ----- Original Message -----
> From: H & J
Johnson
> To: Rotary motors in aircraft
> Sent:
Wednesday, January 31, 2007 8:09 AM
> Subject: [FlyRotary] Re:
New Cowl Contest
>
>
>
> George, its a
Gantry Mill, the parts sit almost right on the
> floor and the gantry
runs on two long side rails which are bolted
> into the floor. Attached
is a picture showing a similar type of
> machine. This particular unit
is from Scaled in So-cal. Mine is
> smaller than this unit, but then I
didn't have the budget that
> they do :-)
>
> I'll
have pictures/vid's up on my website, which should be in
> about a
month.
>
> Jarrett
>
>
>
> ----- Original Message -----
>
>
>
From: George Lendich <lendich@optusnet.com.au>
>
>
Date: Tuesday, January 30, 2007 3:58 pm
>
> Subject:
[FlyRotary] Re: New Cowl Contest
>
>
> >
> > Jarrett,
> > What sort
of CNC is that ?
> > George ( down under)
>
>
> >
> >
> >
> >
> >
> > Dave,
> >
> > I'd vote for the smiley, I would
still wonder if having the
> > opening out off the bottom face
of the cowl wouldn't be
> better.
> > Mind you, two
other things come into play. There probably
> isn't to
>
> much [more] turbulent air or thicker boundry layer that close
> > behind the prop at that location. No more than the
turbulance
> > farther out. Secondly, the rotational vector up
close to the
> cowl
> > very well could be less than
farther out.[ to exagerate the
> issue,
> > imagine the
rotational vector out near the prop tip's.]
> >
>
> I've designed a few cowls over the last couple years.
> Attached
> > are a couple pictures to illustrate.
Since you plan to use a
> lower
> > and upper ducting,
I've attached drawings/pic's showing how
> I've
> >
done both designs. It would be a simple matter to combine the
> two,
> > to arrive at your desired design.
> >
> > Also I've not said much in the past, but my CNC mill
has been
> > installed and is just awaiting final wire-up and
commisioning.
> I
> > plan to start offering its use to
the Rotary crowd in
> producing
> > components like
cowls, proper diffusion ducting, spinners
> [which
> >
properly fair into the cowls] etc. Theres many other
> components
> > I'd like to get into building but plan to start out with
these
> few
> > and expand from there. The mill is
currently capable of
> milling
> > parts up to 8 x 18 x
3 [feet] and will be upgraded in the
> spring
> > to
have a 4ft [instead of 3] Z axis. Later, we plan to expand
> its
> > abilities to 5 axis, however this is more in the
neighbourhood
> of
> > a year or so.
>
>
> > I'll have a website up in the next month or so.
However the
> > meantime, if I can be of help, please let me
know.
> >
> >
> >
> > Jarrett Johnson
> >
>
>
> >
> >
> >
> >
> >
> >
>
>
> > ----- Original Message -----
>
>
> >
> > From: David Leonard
<wdleonard@gmail.com>
> >
> >
Date: Tuesday, January 30, 2007 2:22 pm
> >
>
> Subject: [FlyRotary] Re: New Cowl Contest
> >
> >
> > > Todd, if it aint broke dont
fix it!!!!
> > >
> > > You
are right about the boundry layer. But you can make up
>
> for
> > > that with a
> >
> little extra size or maybe moving closer to the prop (eg P-
> > 40).
> > >
>
> > Also, Doug dempsy has been telling me how Chuck Dunlap had
> a
> > real
> > > problemwith
a duct that was away from the boundry layer,
> but
> >
fixed
> > > his issue when
> >
> he make it bigger and more like the smile.
> > >
> > > The smile votes seem to have it so far...
> > >
> > > Dave Leonard
> > >
> > >
>
> > On 1/30/07, Todd Bartrim <bartrim@gmail.com> wrote:
> > > >
> > > > I was
thinking that the "oh cowl" would be better at
> > excluding
the
> > > > boundary layer, which would be better
for cooling. This
> is
> > just
>
> > based on
> > > > comments I've
read on the list during previous ducting
> > >
discussions. Based on
> > > > this info, I felt my
oil cooler duct was less than
> optimal
> > (even
> > > though> temps are good), so I figured I
could reduce the
> size
> > of
>
> > my inlet if I
> > > > eliminated
the boundary air layer. As your "smile" duct
> is
>
> > similar (see
> > > > attached pic)
I figured this would be applicable. I hope
> I'm
>
> > wrong and you
> > > > prove it
before I change my cowl.
> > > >
>
> > > Todd (building Electric Bob's Audio
Isolator Amplifier
> > today)
> > >
>
> > > > On 1/30/07, Ernest Christley
<echristley@nc.rr.com >
> wrote:
> > >
> >
> > > > > David Leonard wrote:
> > > > >
> > > >
> > I call them the "Oh Cowl" and the "Smiley Cowl..."his
>
> > > >
> > > > > Go with the
smile, but put a raised ledge on the cowl
> side
>
> > just behind
> > > > > the
spinner to accelerate the air and thin the boundary
> > layer.
> > > Reduces
> > > >
> the ingestion of turbulent air. Check the CAFE
> >
Foundation's drag
> > > > > reduction
report. They have a picture of what it looks
> > like
> > > on a
> > > > >
production aircraft. I have a link to it at home, but
> not
> > here.
> > > > >
> > > > > --
> > >
> >
,|"|"|,
Ernest Christley |
>
> > > > ----===<{{(oQo)}}>===----
Dyke Delta Builder |
> >
> > > o|
d |o
http://ernest.isa-geek.org |
> > > > >
> > > > > --
> > >
> > Homepage: http://www.flyrotary.com/
> >
> > > Archive and UnSub:
> > >
http://mail.lancaironline.net/lists/flyrotary/> >
>
> > >
> > > >
>
> > > --
> > > > Homepage:
http://www.flyrotary.com/
> > > > Archive and
UnSub:
> >
http://mail.lancaironline.net/lists/flyrotary/
> > >
>
> > > >
> > > >
> > > >
> > >
> > >
> > > --
> > > David Leonard
> > >
> > > Turbo Rotary RV-6 N4VY
>
> > My websites at:
> > >
http://members.aol.com/_ht_a/rotaryroster/index.html
> >
> http://members.aol.com/_ht_a/vp4skydoc/index.html
>
> > http://leonardiniraq.blogspot.com
> >
>
> >
> >
> >
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> ----
> > -----------
> >
> >
> > --
> > Homepage:
http://www.flyrotary.com/
> > Archive and
UnSub:
> http://mail.lancaironline.net/lists/flyrotary/
> >
>
>
>
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>
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>
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