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Oct 31, 2014, 10:27 AM
Ad eos qui nesciunt crepitus
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Build Log

UberPfeil (Super Arrow)


I gave up on the CF 105 Arrow after several attempts to get the EDF mounted......came back into the house, sat down at the computer and came up with this......another morph of the Jetstream....

I'll post the drawings and patterns if anyone is interested.

why I gave up on the 105...I fired up the EDF and it wouldn't stay in the bulkheads....nothing seemed to want to stick to the plastic housing of the EDF....'course, watching the motor go through the front of the aircraft in mid-flight might be worth a look or two....or.....once!

Here's the drawing and the patterns.....thanks Rick !

Update 11/5/2014: fitting out and bench testing this morning....and everything was going fine until I heard "CLUNK" and all the fan blades exited the rear of the aircraft and imbedded themselves in the foam backstop I'd set up.....so, two more hatches in the bottom of the fuse and a new impellor. good to go !

Update: 11/7/2014........Too much weight and not enough thrust....and now I have a Concorde....so I eliminated the lower fuse, added another fan and stuck them to the side of the fuse...added a little bit of wing and got the elevons in the jet stream.
Last edited by Old_Pilot; Nov 17, 2014 at 08:49 AM. Reason: Added Pictures
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Oct 31, 2014, 11:03 AM
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Too bad about the CF105 problems . You are in good company as far as giving up on it though . We had a "farmer" prime minister at the time in John Diefenbaker who did the same . Scrapped the whole program in about 1954 at the behest of the likes of Lockheed , Grumman and others as the CF105 was well ahead of the pack for an interceptor . Its technical specs were finally surpassed decades later by the F-16 which had the avionics / fly by wire technology . The CF105 was all done with hydraulics . There were recent rumors of re-tooling this design with all of the new avionics instead of going with the F-35s.

Awesome job on the new bird ! Rick
Oct 31, 2014, 09:14 PM
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Actually, I remember a variation of the F-104 competed with the F-15 Eagle back in the 70's. I don't know too much about it but I remember reading it a couple of times. Apparently the Starfighter variant did well, but I think they like new and aesthetically pleasing planes. Take for example the F22/F23 competition. I think the F22 won because it was better looking.

Anyway, that side track aside, sorry the EDF didn't work on your Arrow.
I'm not sure what kind of EDF you had. The one I bought had tabs on each side and 3 bolt holes on each tab. Once you glue wood hardpoints for mounting, it should work fine. Unless maybe your EDF didn't have mounting tabs?

I haven't made the leap to foam yet, but have been meaning to. Foam is a good bit more durable than balsa too. I still like working balsa though, but I really do think foam might be the building material of the future.
Oct 31, 2014, 09:39 PM
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mounting an EDF


Hey BD,

no tabs on this EDF....it was salvaged from another aircraft.....but I guess I could use some model airplane glue (Testor's) and attach a couple of drilled tabs....I think my clamp system will work too.....and if I put the hatches where I can access the bolts, I can retrieve the EDF without dis-assembling the aircraft.
Latest blog entry: Fuselage Jig for Steve Merrill
Nov 03, 2014, 07:21 PM
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Uberpfeil in the raw


Cut her out and assembled her today......she went together without a lot of coaxing. She be fitted out and painted tomorrow.....Rain forecast for Wednesday so I'll probably (attempt to) fly her Thursday. I changed the EDF hold down straps to heavy duty zip ties.

30 oz without paint...Guessing AUW will be real close to 32...oh well, so much for calculations
Last edited by Old_Pilot; Nov 03, 2014 at 08:09 PM.
Nov 06, 2014, 09:30 PM
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And now I have a Concorde


64mm edf isn't enough ummpff...so I'm going to add a second one....eliminating the lower fuse and putting the fans on each side of the fuse just in front of the fins
Latest blog entry: Fuselage Jig for Steve Merrill
Nov 07, 2014, 10:00 AM
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Do your fans have a fairing around the intake? They should. If you don't have an intake duct, the fairing helps to increase the thrust. Or so I've read anyway...

I had some concerns after putting a 64mm EDF in my Vampire jet. It puts out some good thrust, I'm just not sure it's enough thrust. I have to try it on 4 cells and see if that's any better. My jet was light, as far as jets go. It was about a pound without electronics. But once you install the EDF, the big ESC that it takes, and most of all, the massive lipo it requires, now it weighs twice as much. Then I was wishing I built a larger wingspan for it.

You may just need a better launch than you can possibly get out of just a hand toss. That's why I suggested provisions for a bungie launch. But you might have enough static thrust with two EDFs on it, so you can try that first.

I've also read that EDFs with a higher blade count make more static thrust at the expense of ultimate speed, and are better for intake duct-challenged situations (which yours is not).

It's just an idea, but have you thought of building a pusher prop version of this same plane?
Not only will you get lighter weight, but it'll fly right out of your hands, if you power it right.
Nov 09, 2014, 07:23 PM
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Hey, I just built myself an UberPfeil.
Thank you for sharing your plans with me, Charlie.

I did a few things slightly different to suit my tastes however.
I added an airfoil to the wing, and I extended the wing slightly with turned up winglets.
I am going to power mine with a pusher motor.

This is my first-ever foam board build, so it might look a little rough, but I'll clean it up and then paint it. I can't wait to see it fly.
Because of my changes, I came in at 7.8 oz. But the motor will weigh a lot less than an EDF, so it should be okay. Mine is smaller too, I think.
I've got a 30.25" wingspan and it's 32" long.

Check it out...
Nov 16, 2014, 11:54 AM
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Twin Arrow


(2) 64's on a 31 oz airplane......If I got the efflux right, she should generate close to 3.5 lbs of thrust....nacelles are courtesy of the USPS..the rest is Elmer's Board
Latest blog entry: Fuselage Jig for Steve Merrill
Nov 16, 2014, 12:35 PM
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Looks great! Dang, what kind of a battery are you going to have to use in that thing?
And what's your weight at currently? 3.5 lbs of thrust should fly it, but I'm almost wondering if you're still going to need a bungie to get the speed up. The launch is the hard part with these jets. You know, you could always mount landing gear in one of these if you wanted to.

The Midi fan 90mm EDF that I'm planning to use for my Sundowner is supposed to make something like 11 pounds of thrust from an 8 cell lipo. Gawd that's large. I'd have to have 2 pounds of batteries in that jet, minimum. With these EDF jets, it's always a struggle to get enough thrust for the weight you end up with.
Nov 17, 2014, 08:52 AM
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Batteries


Hey,

I'm going to run (2) 2100 mah 20C 3s, (2) 40A ESC's....Two smaller batteries to get them far enough into the nose to balance the aircraft, one on either side of the nose stiffener
Latest blog entry: Fuselage Jig for Steve Merrill
Nov 17, 2014, 09:07 AM
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That's what I was planning to do with the Vampire too. Smaller batteries to keep weight down and still run the motor hard enough to fly. Have you calculated your anticipated flight time? I'd imagine you'd get a few minutes anyway, but as much as those motors pull, you probably do want to know to keep a timer on it.

How's the weather?
Its 11 degrees right now, with a 2 mph breeze.
This is in Clovis, NM!!! Can you believe it?
If it weren't for the cold, it would be an excellent day for flying.
...I mean, this is as cold as it ever gets here...and it's only mid-November.
Nov 17, 2014, 09:37 AM
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Quote:
Originally Posted by builderdude
That's what I was planning to do with the Vampire too. Smaller batteries to keep weight down and still run the motor hard enough to fly. Have you calculated your anticipated flight time? I'd imagine you'd get a few minutes anyway, but as much as those motors pull, you probably do want to know to keep a timer on it.

How's the weather?
Its 11 degrees right now, with a 2 mph breeze.
This is in Clovis, NM!!! Can you believe it?
If it weren't for the cold, it would be an excellent day for flying.
...I mean, this is as cold as it ever gets here...and it's only mid-November.
cold (30 deg) and windy (15-25) right now.....Wednesday is supposed to be 50 and calm..it'll take me that long to wring out the electrics and time the run on the batteries......

If she's anything like the black jet, I probably won't have to fly her full throttle. Best surprise this morning was that she balances exactly where she's suppose to without any ballast.......
Latest blog entry: Fuselage Jig for Steve Merrill
Nov 17, 2014, 02:29 PM
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builderdude's Avatar
How did you determine the proper balance point?

Mine balanced just right too. I think the long nose helps. I tossed it as a FF glider a couple of times and was satisfied it's balanced pretty close. Just have to maintain that balance as I add equipment.

Are your EDFs set right on the CG? They look like they're pretty close anyway.
Maybe a little aft...no doubt to allow for the battery.
Nov 21, 2014, 07:44 AM
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Balance


I used a Delta Wing CG calculator.....and set the balance at 25% of MAC...it was too far forward. After revising the darawings for Doppelpfeil 2.0, I set the CG at 30% MAC ......

http://www.palosrc.com/index.php?opt...1:ic&Itemid=50

The fans are just aft of the CG
Latest blog entry: Fuselage Jig for Steve Merrill


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