Yes, I was pleasantly surprised by the cost of the rod for the wing spars and ordered enough to do the elevator spars, tail, rudder and tail boom also (more experements needed, but I want to eliminate the wood-carbon-wood sandwich longerons in there too!)

In the tail boom I reckon that if you bonded carbon rods (in place of the wood/carbon longerons) to the outer CF skin and enclosed them under another layer of CF cloth you would probably end up with a plenty strong enough boom, and a much lighter one. I also plan to replace the mahogony ply internal rings/supports with CF/5mm-foam/CF sandwich cutouts - again, much lighter and plenty strong enough.

I'm still pondering various ideas about how to go about making the pilot pod - I reckon there's lots of weight to be lost there.

Phil.

---

From: This email address is being protected from spambots. You need JavaScript enabled to view it. [This email address is being protected from spambots. You need JavaScript enabled to view it.] On Behalf Of KarlS
Sent: 06 March 2012 01:15
To: This email address is being protected from spambots. You need JavaScript enabled to view it.
Subject: [Carbondragonbuildersandpilots] Re: Wing ribs



The rod is actually fairly reasonable on costs. I believe the rod if properly engineered would not cost that much for say a fuselage. Making box beams or triangular beams with foam core and then triangulating them into structures wouldn't be that expensive.

A fuselage nose shell with nice shape and a triangulated tail or box truss structure covered with dacron would look great. Super light weight and simple.

You can always sell the house. Just my 2 cents.

Karl

--- In This email address is being protected from spambots. You need JavaScript enabled to view it., "Philip Lardner" wrote:
>
> I investigated pultruded carbon tubing also and even purchased a sample:
>
> www.easycomposites.co.uk/products/carbon...ction/carbon-fibre-b
> ox-section-8mm-7mm.aspx
>
> This stuff is incredibly light and would be ideal for the straight sections
> of the ribs and particularly or making up the flaperon ribs. There are two
> down-sides to this stuff: at 0.5mm wall thickness it is rather easy to
> crush, and the other problem is... the price! I calculated the number of
> meters of this stuff I'd need and then hid behind the sofa when I worked out
> the price! It *is* a beautiful product, though, and very light weight.
>
> Phil.
>
> _____
>
> From: This email address is being protected from spambots. You need JavaScript enabled to view it.
> [This email address is being protected from spambots. You need JavaScript enabled to view it.] On Behalf Of Kenny
> Andersen
> Sent: 06 March 2012 00:05
> To: This email address is being protected from spambots. You need JavaScript enabled to view it.
> Subject: Re: [Carbondragonbuildersandpilots] Re: Wing ribs
>
>
>
>
>
> Karl,
>
> I wasn't referring to the rod, but to the tubing. The rod bends quite
> easily, but the tubing does not. I'm thinking something along the lines of
> the basic wooden rib only mad from hollow composite. In this application
> (as opposed to the wing spar) there would be a minimum length to get all of
> the load sheared into the rod. I'm thinking MAYBE the uni tape might be
> more apropos on the rib caps?
>
> --- On Mon, 3/5/12, KarlS <kschneider@...> wrote:
>
>
>
> From: KarlS <kschneider@...>
> Subject: [Carbondragonbuildersandpilots] Re: Wing ribs
> To: This email address is being protected from spambots. You need JavaScript enabled to view it.
> Date: Monday, March 5, 2012, 5:59 PM
>
>
>
>
> Kenny,
> We have been using this .125 rod for model aircraft spars. The .125 rod in
> the 12 foot lengths come shipped in about a 2 foot diameter roll. It bends
> easily and would go around the curature of the wing rib without a problem.
>
> www.aircraftspruce.com/catalog/mepages/graphliterod.php
>
> Jim Marske also sold a variety of square rod that may work better. I'm not
> sure if he still sells it or not.
>
> Rick Mullen might be able to answer that.
>
> Karl
>
> --- In This email address is being protected from spambots. You need JavaScript enabled to view it., Kenny Andersen
> <kennyrayandersen@> wrote:
> >
> > I've given this some thought and think it MIGHT be possible; BUT, you'd
> have to make your own rods due to the curvature issues that Phil pointed
> out. Â Also, most rods are actually TOO robust for what we are doing. Â I
> was thinking more like square Carbon tubes so that you still had
> significant area to bond to, and I completely agree with Phil -- you'd want
> some type of gusset at the joints. However, if you used square tube, I think
> you could bond them all rather than use a mechanical attachment. Â Where
> there is a will there is a way. Â I was thinking you could make the tubes,
> as a minimum, out of unidirectional tape wrapped in the 2 oz glass. Â Maybe
> 3/4 X 3/4 test that and see what it got you...
> > You likely have to make the curved ones over foam, then eat the foam out
> with something... Â Just a thought.