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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)
>
>
>
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>
>
> 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
>
>
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>
>
>
> ----- 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/
> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>
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