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Old Oct 22, 2012, 05:30 AM
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hehe... I gave up on magnets LONG ago. I use them in 'proper' adequate places only. Most of my aircraft (Radjet included) use a leading 'tongue' and a canopy slide mechanism at the rear.
Thus 100% assured lockdown.
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Old Oct 22, 2012, 07:10 AM
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Australia, TAS, Claremont
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AERO 10 (RC planes) (14 min 13 sec)


at 3 minutes 25 seconds into this video my Radjet goes into a death spiral, Half throttle fixed the problem.
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Old Oct 23, 2012, 03:47 AM
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Radjet funeral time......

WOW!! FAST!!!
On the 2826/6-2200kv APC4.75x4.75 running 4S 1300mAH 45C it hit 195kph!! And plain to see it is FAST.
Hmmm... let's try the TGXS 5x5 and a 4S 1800mAH 35C battery!!!

I guess it had to be at least a bit faster, but you can't tell that visually. And I never got to GPS Log it.........

Maybe 3mins into the flight I did a WOT pass overhead at about 8 metres, and pulled into a vertical climb.... well ALMOST......
I knew it was fast and thus you don't do dramatic moves, or the G's will be HUGE!! But maybe I over-estimated the strength still.....

So what did it sound like when it self-destructed on the rotation to climb.... hmmm, not sure. There was some noise.... high speed air over foam confetti and pieces!!???
All I saw were two large pieces and some confetti, with the 'noise' of disintegration..... and pieces fluttering to earth then.....

It seemed funny at that time......

The main body and one wing ended 5 metres up a tree..... and other wing and major confetti pieces ended up on the oval. So I grabbed those first then headed to the tree.... climbed and got that down.
Hmmmm...... no battery or GPS unit...... where are they?????

GONE.
A thorough search for over 200 metres ahead of the air where it self destructed, over a wide angle spread, and nothing to be found. Mainly short grass on the oval, and then not too long grass in the perimeter/tree'd area until the road.
GONE.......
45 mins of searching a distance that seemed unlikely to be needed.

But then I thought.... WHAT ANGLE of the climb was it exactly at when it self-destructed??? 45deg? 60deg? I don't know.
So HOW FAR can a 207g battery, that was doing maybe 160kph to 190kph (???) prior to the self destruction, GO ?????
Hmmmm, that sounds possible to go a LONG way!!! A 45deg incline, 207g at 160kph stored momentum..... could that go HUNDREDS of metres!!????

It was about 150m from the approx destruction point to the road passing the oval.... so did the battery and GPS head way off into the houses across the road??? Hmmmm...... I had never thought of that possibility happening!!
The more I thought about it, the more likely it seemed it WOULD have gone a LONG way.... seeing it is reasonably streamlined and heavy, and would have had LOT of momentum.
So yeah... probably somewhere in the backyard of houses across the road... or on their roof... or even to the houses behind those.

So I went home......

The motor had one lead shredded to be just a junky piece of bare copper wires coming out of it - the other two totally fine - but that means it is kaput.
The Radjet pieces CAN be rebuilt fine.... but this time with the carbon fibre full width spars!!!
It will need a new 2826/6 (which I have another).

And farewell to my $17 4S 1800mAH and the $28 GPS logger.....
That is VERY annoying!!!
Not as annoying as the possible landing point of the battery could have caused someone!! So I hope it just hit open yard, or fence or something!
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Old Oct 23, 2012, 09:10 AM
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Quote:
Originally Posted by harlyquin76 View Post
http://www.youtube.com/watch?v=J1O6a...ature=youtu.be

at 3 minutes 25 seconds into this video my Radjet goes into a death spiral, Half throttle fixed the problem.

I still dont understand why people get suprised at this, I have said
many times this is how you get out of it.

Some people are just stubborn /dont like to bo told they are wrong I guess.
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Old Oct 23, 2012, 11:11 AM
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Cool vid Harly, and good story Peter even though it has a sad ending
Where did you find a $28 GPS logger by the way? Got a link?
Thanks!

I've got Radjet fever... not even done with the Dually and yesterday ordered another kit from HK's US warehouse. Figured I have an extra 2826 motor and ESC, plenty of servos, extra set of wings and want to try an X-wing design, and do want to have one with left/right thrust vectoring engine mount and a Harlyquin-styel canard so why not.

Putting the finishing touches on the dually and noticed the pieces of white tape on the underside covering up 4 holes per fuse. Any idea what these are for? I'm just spackling over them, and have CA'd 1/16 basswood blanks over the finger detents to have a smoother underside. Will probably put a large Dubro tail skid in the middle for throwing.

Also cut and reinforced the center elevator and properly hinged the ailerons.

Weight of the bare airframe will be ~450g, with all electronics and batteries ~900g.

The biggest decision now is paint scheme. As cool as a military grey or black would look, for vis I'm leaning towards a red/white/blue combo something like this:
http://www.rcgroups.com/forums/showp...postcount=2004
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Old Oct 23, 2012, 01:07 PM
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Originally Posted by The_RattleSnake View Post
I still dont understand why people get suprised at this, I have said
many times this is how you get out of it.

Some people are just stubborn /dont like to bo told they are wrong I guess.
We just can't all be as talented pilot's as you. Or have fantastically fast RadJets.

You are the King
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Old Oct 23, 2012, 02:47 PM
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:)

lol
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Old Oct 23, 2012, 03:35 PM
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Cant wait to see some video of your duel radjet fly, also have no idea on what those 4 holes are for (maybe really long landing gear mounts?)
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Old Oct 23, 2012, 04:41 PM
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I need some maths/formulas on projectile trajectories and ranges.... so I can work out where to start looking for the battery and GPS.
I figure (guess) that I could throw that battery type about 20m to 30m, so coming out of a ???? (160kph by then?) aircraft, at anything from 30deg to 70deg angle (seeing it must be at some reasonable angle to get the high stress to break), and starting from about 20m up, means it could maybe go 100m to 200m ahead of that??

I have given up on it (battery/GPS) and am not too fussed on getting them back.... but I would like to know where it really went!
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Old Oct 23, 2012, 08:03 PM
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i hate when that happens Peter, i lost a micro sd card out of a wing cam from my 1st onbored flight, only cost $6 but really wanted to see the footage of my friends planes filmed from my radjet for the 1st time.
We spent ages combing the fooball ground for it but something that tiny would be near to impossible to find.
i now put tape around the back of the wing cam holding the card in.
Hope you have better luck.
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Old Oct 27, 2012, 09:15 AM
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the Dually is sufficiently reinforced and smoothed out, servos and control horns mounted and has a coat of primer. Now just need to finalize the wiring, decide how I'm going to lock down the turtle decks (the canopy is fixed to the deck so it comes off in one piece, already removed the canopy magnets) and give her final coats of paint and she'll be done.
All-in weight with two 1300mAh 3S batteries will be ~900g and from a prelim cg check it's within 5-10mm of the stock (single) RJ location.
If I had a bit more skill and forethought would have liked to hide the central elevator control horn (or could have mounted on top to protect the servo but wouldn't like the look up there). Think I'll set up a switch to fully extend the central surface on landing, should act a bit like a flap and also better protect the lower control horn from snagging.
Should have also made the central elevator an inch or two wider. Wouldn't have been difficult, and would have given me extra margin for pitch authority which I hope won't be a weak point.
Twin foam cooling scoops were made from unused P-38 pieces. Not thrilled with how they look but not too bad, and they do make nice handles to remove the turtle decks.
Might just get her in the air before things get REALLY cold up here!
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Old Oct 27, 2012, 01:44 PM
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Switzerland
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It was not my first plan but I got a SK3 2836-2500kV... should be fast

For those who put a 2836 motor, do you remove some wood washers? The motor seems overexposed
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Old Oct 28, 2012, 05:10 AM
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Originally Posted by Gohmer View Post
We just can't all be as talented pilot's as you.
Pushing the throttle stick isnt hard.
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Old Oct 28, 2012, 05:12 AM
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Originally Posted by Kurt View Post
the Dually is sufficiently reinforced and smoothed out, servos and control horns mounted and has a coat of primer.
Thats a great job you are doing there!

Quote:
Originally Posted by Cid156 View Post
It was not my first plan but I got a SK3 2836-2500kV... should be fast

For those who put a 2836 motor, do you remove some wood washers? The motor seems overexposed
Running it on 4s? :P

When I had my 2836 setup, I left the motor as far back as I could, for CG
reasons and also for better cooling.
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Old Oct 29, 2012, 04:23 AM
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Cant wait till she is done Kurt, looking good!!!
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