as civil as I could manage...

Either you:

1) Didn't read my previous post
2) Didn't understand my previous post
3) Are a troll

As I said before and will repeat just this one time more. NO, we can't agree on that – it's simply silly and it is CERTAINLY not dangerous – where the L did you get that? Did you do come calculations that you'd like to share with the rest of us, or are you just shooting from the hip with a mixture of words you read on the internet someplace. The weight difference between two plies of carbon and plywood is trivial for the size of the aircraft and the carbon CLEARLY comes with some advantages – strength being the chief among them (also non-warping, better aging and better moister resistance)! For the shear case, in fact, as I said, the shear bucking for the 2-ply composite is HIGHER than the plywood! Besides, even if you lose a bit of stability from the reduction of thickness it can EASILY be remedied with the addition of a few-once false ribs. As far as strength goes the carbon is WAY stronger -- to suggest otherwise would only flaunt your ignorance of materials.

As far as anything being unknown, if it's anything, it's the plywood!! Go find me some mechanical properties for it!! They are sketchy at best which means practically you'd have to take a big knock-down in strength due to the uncertainty of it. Not to mention the inconsistency of wood properties. Carbon, on the other hand is very well defined and easy to analyze. Plus with the carbon you can orient the fiber any direction you want (if you choose to do so).

In any case you CERTAINLY DO NOT loose stiffness as I pointed out earlier – the carbon is WAY stiffer than the plywood, so if anything you would improve the flutter characteristics. What part of that don't you understand? Would it help if I type slower?

The B-2 bomber is black, made entirely of carbon, and can sit out in the sun without problem. Tons of composite airplanes out there with MANY of those made with a room temperature cure resin systems! – I haven't read of a single one `melting' -- utter nonsense! However, I believe that the CD wing is covered with fabric anyway (similar to Steve's magic dragon), no? – make it any color you like -- don't paint -- use the fabric as the epoxy UV stabilizer.

I hope you will get to the point you understand that there is more to aircraft design than only weight. It's a big issue, but there are all kinds of reasons to do something IF you understand the underlying principles (which I'm sorry to say it's obvious you don't).

The tailboom can be looked at, but with a heavier pilot lightening the tail may not buy you much since you'd possibly have to add that back as ballast. Perhaps making it a bit longer, but keeping the weight down mioght be a combo worth exploring…

The debate is over for me because it's obvious you just aren't going to get any of this due to your unfounded preconceived bias so post what you want, but without analytical proof, which you are incapable of providing, it just static. I've laid out what are likely pluses and minuses for the carbon and the builder can make their own choice. You know in the end you can test it anyway, so nobody but a fool would build one and fly it without testing! So, I clearly don't see the danger that you do.

--- In This email address is being protected from spambots. You need JavaScript enabled to view it., russell wilson wrote:
>
> im not offended or worried about a bit of passion.
>
> do we all agree that it is a waste of a builders time and mony and moor
> importantly dangerous to sugest that...... the d scins can be made lighter
> and stronger using carbon in sheet form,to replace the ply?
> in this particular aplication becaus of the very thin part we are dealing
> with..when we half the thikness(we need to go less than half to be
> lighter) of the part we lose much moor in terms of strenth/stiffness than
> the superior carbon can give back.
> it is also worth noting that the unknowen spring qualities of the
> carbon part at this thinness
> could caus a catastrofic resonance/flutter situation.
> also worth noting is that the collor black in the sun can reach 90 degrees
> celcius,most resins reach a melting point/ temprature to gel..TG of 60
> degrees celcius.if your part is black.you will need to find a higher TG
> resin or paint white and incure a further weight penalty.
>
> i do hope this debate on this particular material/part is over and between
> us all,we have dispelled the myth that thinner sheet carbon is better than
> standard ply.
>
> should we look at the tail boom?is it better perhaps to scin it in ply?
>
> russ...amator..ordinary person..not a profesional..can be wrong.
> On Sun, Jul 17, 2011 at 11:06 AM, slrrls2000 <slrrls2000@...> wrote:
>
> > **
> >
> >
> > Got awfully quite after that snyde remark the one group member made to the
> > other.
> > Let's try to keep it cival and on the up and up. We have the best chance of
> > fresh ideas and motivated builders. That is what Jim wantet...afterall.