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Mar 05, 2010, 12:23 PM
PWP!
ajroahkni's Avatar
Discussion

PW1211 dlg


Hi folks,

Trying to find out where the PW1211 hinges as a % of chord from the TE. Also, is this foil (in it's natural form) already w/ the reflex typically needed to trim flying wings?

Thanks,

John
Last edited by ajroahkni; Apr 15, 2010 at 07:16 PM.
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Mar 05, 2010, 04:18 PM
Registered User
Dear John

as the airfoil is made for lower Re (smaller planes), the upper side has not such a long laminar flow (to prevent seperation bubbles). On the other hand the laminar flow on the underside of the airfoil is almost always 100%. So there is no "special" flap chord for this airfoil. So the recommendations are rather general: If you have a very slow flying plane, make the flap chord a bit deeper (up to 30%) flying faster og with bigger planes go somethin in between 20 and 25%.
Concerning the reflex: Again, because it is made for lower Re applications the reflex is somewhat "bigger" than with fx the PW51. So the experiences with this airfoil show, that you will need just a tad of "up trim" to fly slow. With no flap defelction the plane (airfoil) will go in a flat fast glide,about best gliding angle for planks.

All the things metioned above can on the other hand not seen to be totally unconnected with the geometry of the plane....as always.

Hope this helps

Yours Peter
Mar 05, 2010, 04:19 PM
PWP!
ajroahkni's Avatar
Thanks Peter. No better person to hear it from.
Mar 05, 2010, 08:34 PM
Throw it like you hate it
RCPC's Avatar
Quote:
Originally Posted by ajroahkni
No better person to hear it from.
yup.

Thanks, Peter. this wasnt even my question, but i learned something. thanks!
paul
Mar 07, 2010, 01:10 AM
PWP!
ajroahkni's Avatar
Quote:
Originally Posted by Peter Wick
Dear John

Concerning the reflex: Again, because it is made for lower Re applications the reflex is somewhat "bigger" than with fx the PW51. So the experiences with this airfoil show, that you will need just a tad of "up trim" to fly slow. With no flap defelction the plane (airfoil) will go in a flat fast glide,about best gliding angle for planks.

All the things metioned above can on the other hand not seen to be totally unconnected with the geometry of the plane....as always.

Hope this helps

Yours Peter
Peter,

Helps heaps. Because of my tendency to cartwheel, I'm wondering if I can cut away the elevons short of full span to prevent the elevon from crumpling. The concern is having the tips at an organic "down" trim if the actual foil requires some up to trim out neutral. (wing's 48", ~3 to 4 oz loading so it'll be reasonably light, slightly forward swept). I know there may not be a clear answer, but this is my dream ship and want to do it right the first go-round.

The layup is 1.7 kevlar with CF caps at the tip as well as the root (this being 25lb foam and all).

What are your thoughts? Full span on the elevons or would it be OK to leave some carbon out there (which would be my preference)



Can I cut the elevon in the black or better to go full-span?


Thanks,

John
Mar 14, 2010, 02:18 PM
PWP!
ajroahkni's Avatar
Done!
Mar 14, 2010, 02:54 PM
Registered User
That is one good looking plane!
Mar 15, 2010, 12:35 PM
PWP!
ajroahkni's Avatar
I have a thread in the slope forum...but here's the video of the maiden.

Need a little help with my launch technique

The PW Project.mov (2 min 45 sec)
Mar 15, 2010, 07:42 PM
Registered User
Thanks for posting - very inspiring! I love your plane - I dreamt about building one like this (in essence a composite Alula). What are the significant parameters (span, weight, wing loading)? It seems to be a nice floater, but it's hard to tell on the slope.

Best,
Mihai
Mar 15, 2010, 07:52 PM
F3B and F3K
RetoF3X's Avatar
Hi John
Nice plane and great location to fly, thanks for sharing!
You seem to have a sturdy transmitter.

Reto
Mar 15, 2010, 08:03 PM
PWP!
ajroahkni's Avatar
Quote:
Originally Posted by Mihai
Thanks for posting - very inspiring! I love your plane - I dreamt about building one like this (in essence a composite Alula). What are the significant parameters (span, weight, wing loading)? It seems to be a nice floater, but it's hard to tell on the slope.
It is longer, thinner and less sweep than an alula.



As shown in the vid, I'm at 9 oz, 4.5 oz/sq ft loading (I made the planform w/ 2 sq ft just for loading calcs ).

The wing is laid up pretty heavy as I don't need a flatland plane, but the "PWP" as I call it handled the sloppy conditions pretty good. I have no doubt that the planform could be AUW 6.5 or so (3.25 oz/sq ft) as PWP's nose is long and tail is balsa, laminated (0.5 oz). The pod is actually dougmontgomery's "curb appeal" pod for 50" DLG.

The DLG blade will be installed this weekend.

Peter Wick mentioned an increase in camber for better thermal ability at the expense of acro. My foil is the stock PW1211.

Reto - the Eclipse7 TX is a brick house!

John
Last edited by ajroahkni; Mar 15, 2010 at 08:20 PM.
Mar 15, 2010, 11:20 PM
Registered User
Looks awesome and flies awesome. Well done sir. If/when I'll try I'll probably go with a light setup, as I only have a puny slope and even worse wind.

Best,
M.
Apr 15, 2010, 07:19 PM
PWP!
ajroahkni's Avatar
pwp*dlg.mov (3 min 55 sec)
Apr 15, 2010, 07:44 PM
Registered User
My favourite "this is sloping" video of all times!
M.
Apr 15, 2010, 10:21 PM
Red Merle ALES VII SJ
Curtis Suter's Avatar
Excellent!

I would be very interested in still air flight time from a DLG launch.

Curtis
Montana


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