[Paparazzi-devel] Re: Steve Turners Post

[antoine . drouin]

Hi everybody

Hugo Vincent wrote:

>Hi Steve,
>
>I am working on a UAV project too; I haven't made a website yet, but have
>written and collected a fair bit of material in the attached PDF  file (
>) -- but I am not sure how the mailing list system will handle it. (It's still
>in a state of change, so ignore anything that looks unfinished or wrong!)
>Please feel free to use the ideas in it, and consider releasing your work under
>a GPL type license so we can all share

It's very interesting, but i think you'd better not send such big attachment to
the list. You could put it somewhere on the the web and send a link to it.

If you like, we can host your document in the paparazzi CVS at savannah.

>I have just looked at your website -- cool! I would like to know more about the
>airframe: did you design it? The specifications you came up with -- how where
>they generated/based on?
>
>I have been playing around with SolidWorks/COSMOSworks (3D Cad and analysis
>plugin that does stresses etc, and aerodynamics), and XFoil (GPL airfoil design
>tool and simulator) trying to design an airframe, and am getting fairly bogged
>down in it all! I must say, just from looking at your website, that you sort of
>just got out the tools and started making it, with out really doing the design
>and calculations (no offense, I wish I could do that).
>

which airframe are you talking about ? The twinstar is a ready to fly kit from
multiplex. We choosed this plane because it is well suited to our need : it
flies well, doesn't need a runway, is very "heavy duty" and very cheap. Wing
mounted motors have the advantage of protecting propellers during landing and
leaving the nose of the aircraft free (for the camera..)

>Also, for the airframe, especially the wings and tail-plane surfaces, you might
>want to investigate a technique called vacuum bagging, where you lay-up the
>foam with all the various composites, add an anti-stick film, put it in a
>sealed bag, and apply around 4-8 psi of vacuum pressure. Alternatively you can
>use the parts of the foam that you cut the wings from ("negatives" or
>something, sometimes called shucks), put your layed-up wing in them (with
>appropriate anti-stick protection) and puts weights on the shucks to apply
>pressure to the lay-up, increasing strength of the bond to the foam, and as a
>result, the strength of the whole wing, and allowing less epoxy to be used
>(less weight). 

The maxi kiool was build using this technique. We have almost abandonned this
airframe, due to its fragility. Motor gears are not very well suited as landing
gear :)

Regards

Antoine