>Yes it's us Dave. Please put aside the bottle.
>Friends don't let friends build aeroplanes drunk.
building sober? but all the numbers on the ruler thingies will be different.
when they are just fuzzy it's kinda easy to just guess at a number. Actually
knowing it might put a twist on things ;-]
Uh huh ;-]
>> Hopefully we will get good responses from all over.
I'll post it to what places I can. I'm going to post on the french lists
about this and the may annual cri builders meeting (time/date etc).
Hopefully we'll get a few more people.
>Yes, how about starting with you. Tell us about your
>solid foam core wing research. I could use a refresher
Ok. I'll write this for anyone outside of our contact group. Assuming
there will be extra list activity. Basically in some areas of north america
the klegecell foam is either hard to find or expensive to purchase, with
the odd quality question thrown in as well. My experiment is to replace
the klegecell ribs with a solid foam core of lighter material. The solid core
get hot wired to shape exactly like r/c airplanes or even some of the
Quickie/Eze's Berkuts,Europas etc etc. So instead of having 30+ individual ribs
that need to be aligned/jigged for assembly we have a solid core. The cost
core will be $24 CDN each wing and about $15 for all the foam required in the
tail, rudder, and flaperons. 1/3 of a sheet of klegecell will be used to
ribs blocks around each flapperon connection. The spar is as designed a
metal built up spar (web/caps/ tons of rivets) and as is should survive
ultimate loading. I'm replacing the caps with 6061-t6 of a slightly thicker
to compensate for the reduced strength. This worked out at 12.4 G's
with a possibility of over 15+G's if it holds up.
The 6mm wide klegecell ribs are spaced about 105mm apart so we
have load paths down each rib, and the epoxy on each end is the bonded area.
the solid core we have a 100% core glue skin contact area so there are no
The loads are spread evenly through out to provide a true stressed skin
It basically means the local loads are lower as they are spread out more. As
the glue loading per sqr inch will drop to about 1/10 the stock value.
This method eliminates basically all the jigging tooling required with the
It also cuts the cost down, materials are local and available.
> Also, do you plan to do a static load test
>on your solid core wing?
I've got the extrusions, the skin and just need foam and rivets to built a
Then of course sandbags and a fixture. since it's not a huge airplane won't
of either. Half span load at 10 g's is about 2000lbs so that could be as
little as 20 bags
of something. I'd like to test the load at increments of 1/10 G and will
along the half span and at the tip for flex movement. I don't intend to use
the wing to go
flying with so it will get loaded till it goes poof. Normally you only have
to load it up to the
yield point to prove the ultimate. ie 6 g's to prove 9g ultimate. I think by
testing in low
increments and to ultimate I can find out just where any weak points are.