Hi there ,

I'll start soon the building process of a Byron A-4, and plan to modify it for the 12lbs turbines.
I will need to strenghten the wings as the byron spar just rests in foam, and I was wondering how to do that and keep it light?
I was first thinking of replacing the die cut ply spar (1/64...) for carbon fiber then cover the whole wing with light carbon fiber?

Has anyone done that, even to an F16/F18 or any other Byron jet, I believe they all have the same basic construction?

Thanks
Florent

Hi ,Im doing my 3rd Byron conversion the 2nd for the 12lb turbine, you don't need to do much the carbon is over kill. I used balsa sheeting attached with sorghum, and im glassing wing and tail feathers with 3/4 oz, thats all you need! build light and use automotive paint.

Florent,
Carbon Fibre is overrated (and expensive). For your application, 3/4 oz glass and balsa skins is all you need just like jettset recommends. Save the carbon fibre money and buy more fuel!

Thanks for the advices,
jettset, you mean that you sheeted the whole wing and used the byron wing just like a foam core?
Did you cut the leading edge and replaced it with hard balsa too?

Cobra, for the fuel I'll have to wait a bit... ;o)

Hi Yep you got it,when you wet out the sheeting (I did mine in separate sheets)the water in the glue makes the 1/32 balsa wrap very easily and it sticks like old chewing gum to hair! I only ad balsa end caps, dont mess with the leading edge your trying to build strength but without adding weight,I looked into using thin ply but the thin balsa once glassed in more than enough. I would also add a spar, on the A-4, you can order the spar kit from Iron Bay, they sell the same ones for scratch builders thats in your A4. Im finishing a BD5J Im building as it were a ducted fan no changes just sheeting and 3/4 oz glass but im putting the motor in the tail no pipe.

Especially with the A-4, CF is not necessary. It's a thick wing, with inherent strength advantages. A little CF in the right places can make sense on any model, but most folks use it for the WOW factor - because it's trendy and is strong enough to make up for poor structural design. If it's a concern, covering of light CF cloth between the wheel wells would be more than you'd need.

Of more importance is to make sure the controls are very stiff. Flex and freeplay that would be fine on DF will come apart at higher speeds.

I'm not a big fan of using sorghum for wing skins, as I had whole wing fall apart in storage after it was skinned with the stuff. THat's in the Florida heat and humidity though. I'd just use West System epoxy.