flyrotary@lancaironline.net Mailing List Archive

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
> > >
> >
> >
> > ---------------------------------------------------------------
> ----
> > -----------
> >
> >
> > --
> > Homepage: http://www.flyrotary.com/
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> http://mail.lancaironline.net/lists/flyrotary/
> >
>
>
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