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Apr 17, 2005, 04:57 AM
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oldpilot's Avatar

Jet Design Contest. Jedi Star Fighter.

I decided to build this model after seeing Alfredo Delgardo's tractor prop design a couple of years ago.
Basically it is built out of 1" thick small cell Styrofoam, which is pretty stiff.
The DF's are two K & P microjets, in series on a Kokam 3S 340 Li Poly pack.
Total thrust with proper entry and exit additions should be 6 oz with an appropriate exit velocity.
All standard GWS small electronics are planned as I have that stuff kicking around in my "Ditty Box".
Cutting out and sanding to shape the basic airframe is the easy part. These major parts took me two hours. The fairing of the motors is more tricky. This first one took over an hour to dope out. the second one should be quicker.

1, The plastic model.

2. The basic parts.

3. The styrofoam forms around the basic DF to smooth the intake airflow to the fan, and the tailcone to increase the exit velocity. Adds 2 oz thrust to each unit

Cheers. Paddy.
Last edited by oldpilot; May 01, 2005 at 02:42 AM.
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Apr 17, 2005, 06:17 AM
Purdue Engineering
Rocketman1092's Avatar
Hope it gets finished in time!
Apr 17, 2005, 07:46 AM
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oldpilot's Avatar

Took a sheet of butchers wrapping paper tonight and drew up the full scale lines to establish the theoretical CG position. I then taped an eraser to the nose at a position which gave me that CG. Flew beautifully in the living room!!! Theres hope yet.!

Cheers. Paddy.
Apr 23, 2005, 08:41 PM
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Drawing out the lines to calculate the theoretical CG position

The parts taped together while the glue sets. "Kipper" RPA. Sets in 25 min.

Rear view. The twin jets sit under the wing, at the back. So I guess I am going to need a heavier battery to balance at the correct CG position.

Seven days to go. !!! Patrick.
Apr 25, 2005, 08:21 AM
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oldpilot's Avatar
NO !!! They are not a pair of binoculars, they are the Ducted Fan units, primed and ready to got into the lower "Keel" of the airframe.

Finishing with lightweight filler and acrilic paint will make them look better.

All electronics are installed and the jets are glue drying overnight. Will be able to have a static test run tomorrow. The Elevons have been installed, hooked up and tested. So far so good.

Five days to go, Finish and painting is going to be the time comsuming bit!!!!

We are having wonderful weather right now.
Wanna bet it's going to be raining when "Maiden" time comes around.

Cheers. Patrick.
Apr 25, 2005, 08:36 AM
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oldpilot's Avatar
UH ! OH !
Preliminary weight and balance trial shows this model is going to be MEGA tail heavy. I shall have to use a heavier battery.

I have a 3S 2600 Li Poly, but am wondering if that is going to be overkill.???

Cheers. Patrick.
Last edited by oldpilot; Apr 25, 2005 at 09:09 AM.
Apr 25, 2005, 05:30 PM
Watts the Point
netmechanic's Avatar
It will balance better once you get your R-2 unit installed, there pretty heavy
Apr 26, 2005, 12:18 AM
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oldpilot's Avatar

The glue dried overnight alright. Only prob was it was RPA and it expanded to include my right elevon pushrod.

Now I have to waste time dismantling it and cutting it free. DOH !!!!!

More haste less speed. Patrick.
Apr 26, 2005, 08:31 PM
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oldpilot's Avatar
FIXED the Glue blooper in about 10 mins and rigged up the whole system. Ran the fans on a 6 cell NiCad to test. Got 50 Watts at WOT and the fans song was a joy to hear.
The complete plane( not painted) weighs 16 oz with the 3S 2600 Li Poly. So I really wanted 100W of power, although I would have settled for 80W.

THEN DISASTER. It was 10pm and I was tired and should have known better, but I thought I would just try the 3S Li Poly. I got 50 Watts at 1/2 throttle, then I thought "what if" ? and went to full throttle.11.5V, 11A & 125 W.
That was it. Two seconds and the motors were killed. Now it's really a race against time to see if I can replece the motors and get this bird in the air before I paint and decorate it for flying pics.

I need LOTSA LUCK this time.

Cheers. Patrick.
Last edited by oldpilot; May 01, 2005 at 02:44 AM.
May 01, 2005, 03:04 AM
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Gee I forgot to post on this thread and put stuff on the Stickythread instead.

Well Laurie Kelsall to the rescue. Phoned him and had two replacement motors in my hand by 10 pm the next day. A bit of cut and fit and I was in the game again.

Fri at 4 pm got out and flew it "In the Buff". See pics.

Now for painting, decorating and flying,to qualify in the contest.

Cheers. Patrick.
May 01, 2005, 05:59 AM
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HERE IT IS fully painted up and decorated ready for the Fully Finished Flights.

And here is a sneak preview of one of the flight pics.

All details now posted to ARBO. Cheers. Patrick.
May 01, 2005, 01:27 PM
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GRE99's Avatar
Fantastic job! My son and I are avid Star Wars fans and love the fact you chose this suject to build. If it flies as good as it looks I hope you win.Tell me you made plans and drawings please. May I be the first to beg for a copy so i can build one for my sons 7th birthday. Please please please.
May 01, 2005, 01:48 PM
Registered User
Way to go Patrick! Very nice.

May 01, 2005, 02:10 PM
EDF rules... :)
AirX's Avatar
Hey that is pretty neat looking, and great timing too with the new movie opening soon.


Eric B.
May 01, 2005, 05:36 PM
The blade numbers go up to 11
stumax's Avatar
Excellent stuff, Patrick!!! But where are the usual "photo accessories"?


ps. how 'bout flying this week? Wed?

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