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Oct 17, 2009, 06:08 PM
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yellowblue's Avatar
Discussion

Foils for 60" planks in Light air


Ok today we had the 60" EPP Nats...wind was light to nothing. Some toys flew/coped better than others.... so there is a big need for a new toy to handle these conditions.....This would be a homebrew toy not a commercial one
I would like to pick your brains on what would be a good foil for 60" flying wing (plank'ish format).
I've used MH64 in the past for light air, an was wondering if any of you have found anything better.

Thanks in advance Brian
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Oct 17, 2009, 06:17 PM
by ZIPPER
ZIPPER's Avatar
Pw51
Oct 17, 2009, 06:24 PM
Registered User
yellowblue's Avatar
Quote:
Originally Posted by ZIPPER
Pw51
I've used that a lot, it seems to prefer a bit of a blow
Oct 17, 2009, 07:26 PM
speedfreek
alkoo's Avatar
PW75?

From recollection, Peter Wick designed it for lighter air.

Maybe Peter can chime in here.


Waz
Oct 18, 2009, 05:10 AM
Deniable plausibility
Shedofdread's Avatar
There was another one (p1121?) that I think he designed for a DLG plank - worth a try?

S
Oct 18, 2009, 10:23 AM
Registered User
From the PW site: "PW106: mainly for more thermal oriented slope flying"

http://www.b2streamlines.com/PWairfoils.html

Are we speaking of the traditional taped / film covered EPP wing construction technique? If so, then IMHO, the achievable building tolerances will most likely exceed the differences between many of these similar airfoils.
Oct 18, 2009, 12:19 PM
Registered User
Geode's Avatar
A few case studies for your reference:

Birdwing (PW1211) - https://www.rcgroups.com/forums/showthread.php?t=746520

Composite Manta (AG modified) - https://www.rcgroups.com/forums/show...5#post12434074

EPP Manta (PW51 thinned) - https://www.rcgroups.com/forums/show....php?t=1071157

Also, checkout my blog for other flying wings - https://www.rcgroups.com/forums/member.php?u=133609

Geode
Oct 18, 2009, 12:51 PM
Registered User
ENGINETORQUE's Avatar
Quote:
Originally Posted by yellowblue
Ok today we had the 60" EPP Nats...wind was light to nothing. Some toys flew/coped better than others.... so there is a big need for a new toy to handle these conditions.....This would be a homebrew toy not a commercial one
I would like to pick your brains on what would be a good foil for 60" flying wing (plank'ish format).
I've used MH64 in the past for light air, an was wondering if any of you have found anything better.

Thanks in advance Brian

It's probably less about the section (i.e. use one of the recognised sections that 'works' - PW51 or whatever...) and more about wing loading allied to something that doesn't resemble a bag of washing wrapped in parcel tape and weighing as much as a small car....!

Light winds need light models - something that 60" has been steered away from!
Oct 18, 2009, 01:10 PM
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skirmish's Avatar
Quote:
Originally Posted by ENGINETORQUE
It's probably less about the section (i.e. use one of the recognised sections that 'works' - PW51 or whatever...) and more about wing loading allied to something that doesn't resemble a bag of washing wrapped in parcel tape and weighing as much as a small car....!

Light winds need light models - something that 60" has been steered away from!
You're right that light winds need light models but the standard EPP60 model has evolved into an object to cope as well as possible with a wide range of conditions in which to fly. Most, I think do pretty well with this and i think it has to be healthy for the class that as few models as possible are needed to successfully and enjoyably compete without breaking the bank.

It was noticable though how many folk did have problems struggling with heavier models in light lift - some even used ballast! Very careful smooth flying is also a big factor in keeping aloft and those who are good at that seemed to be rewarded.
Having said that the wind speed for the final was extremely low and no one would normally have wanted to fly in that let alone race!
It's good though that new requirements bring new ideas and developments.
Oct 18, 2009, 02:47 PM
Registered User
Hej

I would go for a PW1211 with more camber or JWL 065 section.

Yours Peter
Oct 18, 2009, 05:28 PM
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yellowblue's Avatar
Quote:
Originally Posted by Peter Wick
Hej

I would go for a PW1211 with more camber or JWL 065 section.

Yours Peter

Thanks for your input Peter, was looking at various foils of yours...wanted to find out what others are using before putting wire to foam.
As Skirmish said, wind was bad, with some sink coming through at times, in some heats paper bags wouldn't fly.

Enginetorque...not bags of washing these days...nice smooth and slick what with the "New Stuff" an yes they can be light, even for a 60" plank...One of mine that was lost in the fire had a loading of 7oz/ft.

Thanks for all your input guys, just trying to move on with the development of our planks. I have some light weight EPP on order, as soon as it arrives I'll be off to the Timinator to burn some foam on his new CNC toy
Oct 19, 2009, 05:08 AM
Registered User
ENGINETORQUE's Avatar
You need a light one and a heavy one - the rules allow a model change presumably ?

Cost isnt' really a factor - two servos, a chunk of foam and a receiver - how cheap is that!
Oct 19, 2009, 10:28 AM
Speed is Good!
rumbey's Avatar
Quote:
Originally Posted by skirmish
You're right that light winds need light models but the standard EPP60 model has evolved into an object to cope as well as possible with a wide range of conditions in which to fly. Most, I think do pretty well with this and i think it has to be healthy for the class that as few models as possible are needed to successfully and enjoyably compete without breaking the bank.

It was noticable though how many folk did have problems struggling with heavier models in light lift - some even used ballast! Very careful smooth flying is also a big factor in keeping aloft and those who are good at that seemed to be rewarded.
Having said that the wind speed for the final was extremely low and no one would normally have wanted to fly in that let alone race!
It's good though that new requirements bring new ideas and developments.
My mistake apart from Paul putting pressure me on was slowing my S-15 up too much in the final. I should have just kept her flying the same as the previous 9 legs....Resulted in stalling it in

The S-15 profile does seem to suit light conditions and is normally good up to 20mph

Also I thought my s15 was lighter BUT its 32.4oz nearly 8oz heavier than Paul Townsends homebrew
Oct 19, 2009, 12:14 PM
Registered User
have a look at Don Ayres (sp?) foils...

I fky at 3000 m altitude and have used his 8% thk, 2% camber foil with great success...

Paul
Oct 19, 2009, 12:23 PM
agony sweetns the victory
atjurhs's Avatar
I've used the PW106 airfoil on a 48 inch wing and it works well, but over time my model has gotten heavier and so more air/lift is required.

From my experience, I do think it's a combo of wingloading and airfoil.

I think I'll check out the PW1211 for the new version of my light sloper....
Last edited by atjurhs; Oct 19, 2009 at 12:30 PM.


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