Depending on the size, a space frame is really over-kill where as a monocoque body with similar construction wings would be fine.
The trend to run to CF only runs the price up on the build. Using good quality glass cloth and resins eliminates the RF attenuation issues with CF.
I say find someone with busted up X8 and use it to make a plug for a fiberglass mold. You could then use the CF rod in critical areas, molded in to the monocoque. It is a time consuming construction method but actually makes a simpler model that you can reproduce.
This way you have total control over the internal mounting points, access hatches, etc.
I am considering such a method for quadrotor #4.
I am sketching out quadrotor #2 now.
Not knowing your experience with building (but I am encouraged at your interest and desire), this is the general idea I had regarding a monocoque X8...
I am envisioning wings made the same way that attach to a central body of the same construction.
You would lay in fiberglass or CF rods of your choice to give added rigidity (but I am not sure it would be needed).
All controls could be internal and access via hatches built into the part.
Kevlar? Wow. If I remember correctly, Kevlar does not respond well to the 'traditional' resins as used in fiberglass or CF.
'Lob' or lab project? How much time do you have for this build? If pressed and you cannot find a donor X8, buy a cheap one to use as the plug.
Warning - some foams are attacked by resins and such. This implies you cannot just take a new X8 and start layering up materials and resins to make a mold. Test an unused area first.
Search for 'fiberglass mold making'
Kevlar laminates fine with epoxy. I use it all the time and have no delamitation problems. However it can be a b!tch to cut!
CF will block RF however there is a material called diolen that looks like CF but doesnt have any electrical properties and will not block RF.
Any styrene based resin will attack foam. You'd need to find a way of sealing the X8 if using it as a plug.
Maybe this one can be used as a plug ?
Look up Twaron too. Its a hybrid weave of CF and black kevlar. East coat fibreglass and easy composites both stock it.
I had a similar idea but couldnt get the X8 at a reasonable price. There's no way im selling the bike :)
just been on the easy composites website and saw this. if theres carbon in it wont it have the same raido problems? due to our stupid laws you can only fly LOS so if some c/f sent the plane down 5km away id be in quite abit of trouble lol. as for the bike. typical british weather. my gsxr sat in the shed for a year so it went sadly.
Make the top canopy from diolen and the rest from CF/kevlar/twaron. That way the GPS has got a window to the sky and the external aerials can send and receive.
Plus if you set the failsafe to RTH you shouldnt go down.
My b12 comes out in all weathers. 250kg gets interesting in the snow