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Old Dec 12, 2012, 06:11 PM
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Pretty sure the Funjet uses a 2200mAh battery, so it's possible your plane is tail-heavy? I have flown a couple Funjets, and I found them easy to fly, no tendency to nose-down due to throttle because the motor is on the centerline. The RadJet and Funjet (Multiplex) are basically the same shape, so I would suggest looking up the CG number for the Funjet and use that. Also make sure you're measuring from the right place - I believe you measure from the point where the wing meets the body - not from the nose. IIRC, it balances pretty far back.
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Old Dec 12, 2012, 06:15 PM
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Originally Posted by headlessagain View Post
Fly
if you have the chance, try to re-maiden into the wind over a slope (at the beach?)
The beach is a definite no-no - fatal for sand in the motor, but there is an ideal slope when the wind comes from the South-West, but this time of year it's from the Northerly direction..brrr

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Originally Posted by headlessagain View Post
It might be best to try to source a replacement motor shaft than try the spare 1200Kv motor from your damaged Decathalon. Pusher jets need high kv motors unless running on a 6S pack! If you do decide on a different motor then I'd head over to the Radjet thread for some ideas..
Andy
New shafts are unavailable, especially since is a no-name motor (why don't they just use proper hardened steel...doh?).

I do have a suitable HK Donkey motor, but I can't get the circlip off the shaft to clean the sand out of it. Anyway I just ordered a nice Grayson 2212-06 because I've read such good things about it and like the look of it.

I'll keep that for when I've learned not to bend motor shafts!
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Old Dec 12, 2012, 06:42 PM
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Originally Posted by jasmine2501 View Post
..Also make sure you're measuring from the right place - I believe you measure from the point where the wing meets the body - not from the nose. IIRC, it balances pretty far back.
I just wish it was mid-Summer, so I can go up the nearby hayfield and do a test glide for different arrangements without risk of more damage... meanwhile, devil-for-punishment that I am, I've got a cheapo HK Flying Wing kit.

Dead easy to assemble and looks really neat, and they even give you a tube of glue! At 300g flying wieght I figured it must have a super-low wing loading, so should be able to fly nice and slow. When I guesstimated it, it worked out to <6oz/SqFt.

When I get some 3mm nuts and bolts I'll fit the AX 1806-N to it...and see if it makes a good lawn dart..
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Old Dec 13, 2012, 01:10 AM
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Fly
you might find the 2500kv AX 1806-N will give you fairly lively performance if running on a 3 cell pack. Here is my Mini Swift using the same motor
Mini Swift on 2500kv motor (2 min 42 sec)

and my scratch 610mm built flying wing on a Blue Wonder 3000 kv 3 cell set up
Mini Wing KFm-4. 610 span. Shot with #16 HD Keycam (2 min 20 sec)

You have been warned
Andy
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Old Dec 13, 2012, 10:22 AM
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Originally Posted by headlessagain View Post
Fly
you might find the 2500kv AX 1806-N will give you fairly lively performance if running on a 3 cell pack...nd my scratch 610mm built flying wing on a Blue Wonder 3000 kv 3 cell set up..You have been warned.
Andy
Actually, it'll be on 1300 2S. I measured the output with various props @ 54w (APC 5x5), 66w (Graupner 5.5x4.3) and 79w (MA 6x3). I ran it full pelt for 60secs and it only got luke warm, so now I got to choose which for easy flying. The 6x3 gives me a modest 119w/lb, so I think I'll be OK with that.

Couldn't help noticing the pesky dog in your video..
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Old Dec 13, 2012, 11:19 AM
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BTW Andy, how do you create a file for YouTube. I've got a Panasonic HD Camcorder and the format needs to be converted to MPEG4?

Guess I got to buy some software to do this?
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Old Dec 13, 2012, 11:53 AM
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Originally Posted by FlyBoy20 View Post
BTW Andy, how do you create a file for YouTube. I've got a Panasonic HD Camcorder and the format needs to be converted to MPEG4?

Guess I got to buy some software to do this?
Adobe Premiere Elements can import the files from Panasonic cameras, I used to use one myself. YouTube seems to eat WMV files without too much trouble, so that's my final format. No video clip should ever be posted without at least minor edits - there's always something you don't need, and the less you can have in your video, the more likely it is to be watched, and it will take less time to upload. Raw HD video should never be sent to Youtube - always render it into another format first.

You can use Windows Movie Maker if you want something free.
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Old Dec 13, 2012, 12:05 PM
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Originally Posted by FlyBoy20 View Post
The beach is a definite no-no - fatal for sand in the motor, but there is an ideal slope when the wind comes from the South-West, but this time of year it's from the Northerly direction..brrr



New shafts are unavailable, especially since is a no-name motor (why don't they just use proper hardened steel...doh?).

I do have a suitable HK Donkey motor, but I can't get the circlip off the shaft to clean the sand out of it. Anyway I just ordered a nice Grayson 2212-06 because I've read such good things about it and like the look of it.

I'll keep that for when I've learned not to bend motor shafts!
You should be able to straighten it if you're carefull. I've done it to my stock RadJet motor. If you shorten the shaft so the collet touches the motor housing you won't bend the shaft so easily.

A good RadJet CG is the front edge of the finger grip. Launch it into the wind full throttle.
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Old Dec 13, 2012, 12:18 PM
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Originally Posted by FlyBoy20 View Post
BTW Andy, how do you create a file for YouTube. I've got a Panasonic HD Camcorder and the format needs to be converted to MPEG4?

Guess I got to buy some software to do this?
I use Windows Movie Maker that was bundled with MS Vista Ultimate. It's easy to use and has enough features for my use. Camera is the #16 HD Keycam mounted on a foam wedge on my baseball hat peak.
Andy
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Old Dec 13, 2012, 06:55 PM
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I am entirely, profoundly confused by this. That plane should be up and flying, no problem.

The 2212/6 motor you ordered will change your luck for sure, though. I'd run a 5x3 or 5x4 prop on 3S to start out; it will have WAY more than enough power to get the thing up and hoofin' it even if you're not propped up to the max, and a less-aggressive prop will help reduce any possible torque roll issues. Even if the CG is in a bad place, that motor will be like strapping a rocket engine to the back of the plane. There is simply no way you'll have too little power to climb out this time around

Another nice setup for small parkjets and wings that I've really grown to respect is the Suppo 2208/12 (1800Kv) with an APC 6x5.5 on three cells. Excellent combination of thrust and speed for parkflyers in a less-power-hungry package than the 2212/6.
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Old Dec 13, 2012, 07:37 PM
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Originally Posted by C₄H₁₀ View Post
I am entirely, profoundly confused by this. That plane should be up and flying, no problem.
You and me both!

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Originally Posted by C₄H₁₀ View Post
The 2212/6 motor you ordered will change your luck for sure...
Trouble is I'm reluctant to even try it, thinking it might result in another bent/broken shaft..and yet another wasted journey.
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Old Dec 13, 2012, 08:05 PM
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That shaft is made of good 1/8" hardened steel. If it ever comes down to it, your props will break before you manage to bend the shaft. I've been flying and crashing those motors in various winds (930Kv - 2200Kv) for years and I've only managed to bend shafts when running the lower-Kv motors with bigger props on tractor setups.

To do anything at all to that shaft, you'd need a very hard direct hit to the prop adapter, and that... ain't gonna happen
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Old Dec 13, 2012, 08:20 PM
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Originally Posted by C₄H₁₀ View Post
I am entirely, profoundly confused by this. That plane should be up and flying, no problem.
Naw, I've seen this play out at the club quite a few times with planes like the Funjet, Strykers, Zagi, etc...

The thing is, even with lots of power, these planes are kind of hard to launch. So, I have seen people give it a try and something goes wrong, and they crash for whatever reason... and break something critical, then go down a rabbit hole trying to fix it. I think the only thing you can really do is work on the launch, because even when under powered, these things still fly good after you get them going. We used to fly Strykers and Funjets with brushed motors and we did ok. So, it's not about the power level, the technique and setup are much more important.
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Old Dec 14, 2012, 05:48 AM
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Originally Posted by C₄H₁₀ View Post
That shaft is made of good 1/8" hardened steel. ..To do anything at all to that shaft, you'd need a very hard direct hit to the prop adapter, and that... ain't gonna happen
Here's a couple I bent earlier..the one on the left is from the RadLawnjet.
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Old Dec 14, 2012, 05:53 AM
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Good Lord, why is that motor missing its leads in such a vulgar fashion?
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