Scratch Build 60 size Freestyler

[Ian]

The story goes like this......

After seeing both Paffy's and dmichael's amazing scratch build threads, ive been really wanting to build something of my own, my own design.

And also, i love the Fliton Inspire, great looking plane, apart from the canopy, but at £180 its too expencive for me as i cant find a job at the moment. So, what do i do, a few sketches, a final idea, and into CAD i go......

This design most proberbly wont go beyond the CAD stage, as much as id love to do so, i'll most proberbly run out of steem before so. Itll be a long and slow build too

Anyway pictures of the design, from the first CAD drawings, to how it stands now

[Ian]

Pictures, these show what ive done so far, drawing the front half of the fuselage, not including turtle deck, cowl or canopy.

[devin]

Looks great so far. What program are you using to make these and once there made on the program, what do you do?

[dmichael]

Neat stuff, Ian. Keep going. You may build it someday!

Have you thought about this: If you were to take the best freestyle/3D atttributes from current designs and meld them together into a freestyle specific design- not scale aerobatics- what would it look like? I am thinking it would have:

- a mid-wing design like an Extra 260/300 or Edge
- the tail of a Cap (the Cap seems to elevator and harrier like no other)
- undecided about if the wing would be double tapered or straight leading edge like the Edge. The Edge also seems to harrier/3D well though I have very little time on one myself.
- no dihedral and a symmetrical wing of course
- lots of side area like an Extra 300

Dave

[Ian]

Hi Dave,

Ive been looking into lots of different designs and also, ive flown many different planes, so i know whats good and whats not. Ive found that the 0-0-0 design, where the motor wing and tailplane are all in line are the best for pure aerobatics, very nuteral in all axis. Yes, the cap may harrier the best, but its high tailplane low wing make it a pig in knife edge. However, to make a pattern plane type design, which this will be, it looks a bit stupid with a central engine, so the engine will be higher than the wing, but the wing and tail are in line. I dont think this will make too much difference, as many planes from smaller electric jobs to 40%ers have this, and fly perfect still.

Also, as im looking for this to be a smooth plane which flies 3D too, it needs to have a fairly decent moment arm, lots of the planes i have flown, which may be the best for 3D, cant fly smooth to save themselves, all cos of the moment.

Another thing, the Edge 540s wing platform is great for high alpha as it has, in practise, even though it doesnt look like it, it has a forward sweep on the wing, which is great for harriers and tumbles, but it isnt as good as a taperd wing for precision, and of course a strait TE seems to be even better for smooth, as the giles 202 is just brilliant at it, yet isnt as 3D capable. A double tapered wing, like most designs have, seems to be the best option for a smooth/3D mix.

So basically, i have gone for this:
Wing and tail inline, motor slightly above
Double tapered wing, with a quite thin section, i have drawn one out that i like the look of, just need to find a "real" one that looks like it
Large side area too, as you can see, the fuz is quite deep already, and thats without turtle deck or rear deck. Quite large rudder too with smaller counterbalance for good KE performance.
Slim fusealage, i know this isnt as good as a wide body fuz for downline drag, but it does look really cool!

Below is the attached drawing of my first sketch. Everything was taken off this, put into a full size plane, then into CAD. Sorry for the poor picture, it was just taken on my camera phone. The wing is too big at the moment, but when i draw this properly, i will make it about right size

Devin, the pogram isnt anything posh, its called ProDesktop. Its the educational version (im still at college) of the program ProEngineer. Its really easy to use (for a CAD program that is) and produces good results, and will save in loads of different formats so i can use the CNC cutters or laser cutters.

[Sandbag Special]

sexy

[Ian]

bit more of an update....

my maths is doing my head in (obviously 12 years of it at college isnt enough to design a plane!) so im strugling to get length of the fuz right, im pretty certian the formers are correct length. ANyway, a few more images of tonights progress

[SargeNZ]

	Quote: Originally Posted by Ian
	Double tapered wing, with a quite thin section, i have drawn one out that i like the look of, just need to find a "real" one that looks like it

Try taking an Eppler 479 and thinning it a little (to 12% maybe??)

[Ian]

looks about right, i was thinking of it about 12% anyway. The only other thing i thought was maybe to move the high point a little further back..

anyone know where i can get a dxf of the above wing section?

[Ian]

well it turns out i had my rear former messed up, thats why it didnt look right. so that fixed, with some stringers temp. attached. Next to do is make the elevator and servo mounts (going for a single elevator servo at the rear, rudder servo in the fuz), then do the rear sheeting, then start on the tail surfaces

[SargeNZ]

Structure is looking kick ass dude. I would be interested to watch this one finished.

http://www.mh-aerotools.de/airfoils/index.htm - Good reading about airfoil design. get Concord, the piece of software that lets you convert between the various airfoil formats. Includes points file to dxf.

http://www.nasg.com/afdb/index-e.phtml - Airfoil database... more airfoils than you will ever need

[p sme]

	Quote: Originally Posted by dmichael
	Neat stuff, Ian. Keep going. You may build it someday! Have you thought about this: If you were to take the best freestyle/3D atttributes from current designs and meld them together into a freestyle specific design- not scale aerobatics- what would it look like? I am thinking it would have: - a mid-wing design like an Extra 260/300 or Edge - the tail of a Cap (the Cap seems to elevator and harrier like no other) - undecided about if the wing would be double tapered or straight leading edge like the Edge. The Edge also seems to harrier/3D well though I have very little time on one myself. - no dihedral and a symmetrical wing of course - lots of side area like an Extra 300 Dave

Hey Dave
Im scratch building a 35% right now thats pretty much like that. It basically has the cowl, canopy, and tail of a CAP a slightly lower than mid wing(not nearly as low as a normal CAP) and a straight leading edge. I don't want to hijack the thread but I have a bunch of pictures. At this point I pretty much have the fuse completed.