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Old Apr 23, 2006, 02:40 PM
registered foam addict
chara's Avatar
Munich, Bavaria
Joined Dec 2004
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Build Log
"Harpy-Cat" .... foam pusher jet

I've followed those popular Bob/Alley/Jet/Fat/Callitwhatyoulike-CAT posts with interest and I liked the design of "the cat" more and more and wanted to build something similar.
I also was in the phase of redesigning one of my last years favorites the Harpyia (forward swept wings this time )
http://www.rcgroups.com/forums/showthread.php?t=435688.
Since I'm a lazy swine I thought I'd do both things at the same time, take my favorite features of both and merge them to a new design .

That's how far I got during weekend...

Features:
- forward swept wings, strakes, twin-fins for better low speed/High AoA performance
- pusher configuration with elevator in slipstream for that extra "bite your tail authority"
- full fuse to neatly hide those ugly batteries/leads/electronics and cleaner aerodynamics - more speed (thanks vyceroy for the inspiration)

greetings
chara

UPDATE: find PLANS collection on next post!
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Last edited by chara; May 01, 2008 at 01:28 PM. Reason: it's going to be a build log rather than "discussion"
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Old Apr 23, 2006, 02:49 PM
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Munich, Bavaria
Joined Dec 2004
1,265 Posts
...more pics....

...It was also a good exercise for 3d CAD. and so easy to take the "pictures"

As you can see dimensions will be 48x58cm. I want to stay below 250g AUW. 11V/7A outrunner brushless with a 5" Günther prop (up to 7" prop possible).
I try to minimize build effort and number of parts to be cut out (reason: see previous post ).

in case someone is interested I'll keep posting about the outcome (chuck glider flies very nice so far).

-chara

UPDATE:
Following SGTalon's suggestion here we have a collection of all HARPY versions so far with PLANS (as far as available)...
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Last edited by chara; May 01, 2008 at 01:33 PM. Reason: author can not read his own graphics. it is 48cm not 45cm ;)
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Old Apr 23, 2006, 03:13 PM
Krued Up
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United States, MA, Springfield
Joined Jul 2004
4,492 Posts
Me likey Chara.I'm with you on this one. looks awsome.

Angel
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Old Apr 23, 2006, 03:15 PM
JAM
MaxAmps CMO
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Nine Mile Falls, WA
Joined Jun 2004
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Chara rip me a set of plans...........If you don't mind I'd like to give this a whirl.......I'll post what I come up with here.........I love the look........

JAM jenjay5131121@earthlink.net
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Old Apr 23, 2006, 03:28 PM
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Munich, Bavaria
Joined Dec 2004
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Thank you guys! I'm glad you like it!

Jam I'll be happy to send you anything I have available. I'm working on the servo and control surface setup right now. I have got some ideas how to further increase low speed controllability and maybe even compensate propeller torque. If you don't mind waiting until tomorrow I'll mail you the latest plans, 3D snapshots and parts layout ... I love that 3D CAD stuff! )

chara
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Old Apr 23, 2006, 03:58 PM
JAM
MaxAmps CMO
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Nine Mile Falls, WA
Joined Jun 2004
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That would be great.........I'll check my unwanted e-mail slot when I get home Monday night from work....I'm sure it will end up there seeing that I have never got anything from you before.......I can't wait to see it........thanks and later.....


JAM
Jason
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Old Apr 23, 2006, 05:34 PM
The Big Kahuna of Foam.
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Columbus, OH
Joined Mar 2005
1,170 Posts
Looking good! I'm up for building one.
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Old Apr 23, 2006, 05:39 PM
Or am I...
Bournemouth, Dorset, UK
Joined Jan 2005
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Cool. Lets see some foam!
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Old Apr 23, 2006, 07:41 PM
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United States, IN, Indianapolis
Joined Dec 2005
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Chara ,

That look like you have Rhino 3D ( or similar ) well inhand.

If you have a mind to release this desing I wouldnt mind giving it a GO !!!
I can handle most 3D formats 3ds 3dm etc.

I just finished a Housecat and here is what I posted in that forum

--------------
While I LIKE my HouseCAt ( 24" version ) see previous posts,
It is NOT the speed demon that has been advertised
at least not IMHO.
I get 21K rpm at the bench which is ~ 60mph pitchspeed
I expected a bit more "unloaded" speed.

That said it IS still totaly VERTACULAR !!!

Like, point it up and it just never stops.

To sum it ip ... Still happy, still flyin :-)
ref:
http://www.rcgroups.com/forums/showt...48#post5375660

--------------------

Suming it all again - I'm with you !
The "cat" design needs to be a bit cleaner to get some serious speed.
I was waiting for Vcroy but if you wanna release the 3D then I dint need plans.

A local guy an I fly these all the time.
He is from Neukirchen am Großvenediger
over on the othe side of the Mntn :-)
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Old Apr 23, 2006, 07:46 PM
G G Ghost Pirates !!!
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USA, NC, Gastonia
Joined Dec 2001
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BOP heres the link to the thread with the fatcat plans .. Fat Cat Thread

Looks Great Chara .. gotta love those forward swept wings .. is it a flat plate or a wing with an airfoil??
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Old Apr 23, 2006, 10:22 PM
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Subscribed
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Old Apr 24, 2006, 06:05 AM
gpw
“There’s no place like Foam”
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United States, LA, New Orleans
Joined Jul 2002
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No reason It shoudn't be a super flyer... FSW has great flight characteristics , and after all , if the chuck glider flies well ....
Chara, you have a great eye for design , I really like your Bipie too ....
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Old Apr 24, 2006, 11:56 AM
CNC Cutter
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United States, IN, Indianapolis
Joined Dec 2005
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Thanx Vyceroy

No reply from Chara so I guess I'll do my own
from those plans
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Old Apr 24, 2006, 02:14 PM
HOW HIGH DOES IT GO???
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Jacksonville, Florida
Joined Nov 2004
2,153 Posts
Man I really like your design. I'm down for building one. If you wouldn't mind emailing some plans my addy is benrod65@hotmail.com or just post them here. I'm sure many more guys will build this. Really looks like it will be a great flier and you already have a chuck glider, sign me up. Like Bird said, might not be too tough to build from the pics provided.

Ben Rodriguez
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Old Apr 24, 2006, 05:15 PM
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Munich, Bavaria
Joined Dec 2004
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Parts Layout

thanks for the kind words everyone!!!
I'm just as excited to start the build an try out how it flies.

vyceroy,

the wings will have a flat profile. probably reinforced with a carbon spar if I find them to be to soft. The build will be mainly 6mm depron so if you stay with small size and light weight it should be rugged enough without reinforcements.
I'm also thinking of a larger version with airfoil-profiled blended wing-body, but not for now...

BOP,
sorry for the late response - that's because of the fact that I sit at the opposite end of the globe and not because of impoliteness . I'm sure you're gonna have much fun with Vyce's FatCat (just love all of his designs) and I'll be following that thread as well.

For all the other guys just waiting to jump right into foam cutting I have a snapshot of the parts layout as a high-res jpg. It will do the job I think.

To release plans before flight testing it is a bit against my "philosophy" but ...ahh...who cares I'm sure your'e gonna make this thing fly!
shouldn't be that tough as Glen mentioned!
In any case please post examples of your work here and share your experience with all of us!

I'll be posting some pics and detail shots for reference as the build progresses....

greetings
chara


modified version under http://www.rcgroups.com/forums/showp...&postcount=422
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Last edited by chara; Jun 16, 2006 at 06:57 AM. Reason: added link to modified plans
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