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Old Feb 21, 2013, 11:52 AM
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thx skydvejam
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Old Feb 21, 2013, 09:43 PM
Once you taste flight...
skydvejam's Avatar
United States, ME, Bangor
Joined Dec 2011
2,782 Posts
Well got radjet2 in, wife looked at me weird when I got in a new plane, and it was the same as the last one I got, then I started hacking it with the knife lol. Wish that they had the ARF in, but PNP works.
Hacked a few vent holes in her, did a few hand held tests, 3s with a 6x6.5 works fine, 4s it is done 3/4 of the way though, 5x5 works great, has the same thrust as the stock with a 6x6.5 pylon prop by my hand felt measurement @ a little over 1/2 throttle, and at full wow..
Also added a carbon spar in the wing, and used both regular, and white gorilla glue depending on the location. A little heavy strapping tape over the spars as well.
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Old Feb 22, 2013, 04:22 PM
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Anyone here ever own HK sky fun or is it fun sky it is similar to radjet made of eps with 875mm wingspan... It seems to have a lot of potential...I read it is a lot slower in stock setup compared to radjet,but also read it can handle pretty large batteries and is good slow and fast...Eps foam holds its shape when it breaks so in a way i prefer it over epo in that respect...I wish more planes where made from epp which is very tough and also holds its shape when crashed...in a perfect rc world there would be know crashes,but i dout that will ever be my world
SkyFun Jet - Great speed And Fun (3 min 34 sec)
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Old Feb 23, 2013, 09:07 AM
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Denmark, kbh
Joined Jan 2012
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I ordered a Radjet kit for a chase car FPV project for which I wouldn't mess up my FunJet, but upon reception I realized how much smaller the RadJet is.

I also realized, that despite building light, I'd have problems with wing load and CoG, so I took inspiration form Harlyquin76's nice canard build and did this:



Once the plane is dialled in, I'll cut the nose and mount FPV camera there (yeah-yeah, I know, "expensive bumper")

To avoid complex, rotating parts and getting the servo to much out front, I opted for a semi fixed canard solution. Servo sits further back in the fuse and operate the rudder surfaces by traditional control rods. The fixed front part is stiffened by a 3x1mm CF stick, that runs through the fuse. Nice and stiff.

To get decent flight times, I'm trying a small 22mm, 80watt outrunner.

AUW (1300mAh 3S, but without FPV gear) around 330gr.

Also added fins on bottom side of wings as recommended by Simon1013 (an aerospace engineer, better take his advice, right?) to reduce infamous "death spiral" tendency. I simply ditched the servo covers and glued in very thin Lexan sheets in the servo recess. They work both as fins and servo protectors this way

Need to program my radio and maiden the little sucker now...

Comments and suggestions welcome.

EDIT: Just made the maiden before it got dark. Very successful; The plane flew well with trims neutral, perhaps a slight climb under power, may need to adjust thrust angle a bit. I was worried that I had underpowered it, but no such thing. Flew mostly at 1/2 throttle and struggled to keep it within view :-) Looking forward to daylight flight tomorrow
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Last edited by mike_o; Feb 23, 2013 at 12:26 PM.
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Old Feb 24, 2013, 10:24 AM
you can always go faster!
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United States, IN, Clear Lake
Joined Jun 2011
33 Posts
First off love the canard idea! My question is what's the best method for launching these? I plan on making a catapult but I am concerned that with the prop being in the back that the ring would hit the prop. I finally was able to launch it underhanded with some success but the esc died(stock) and it nose dived into the ground :/....I love this thing and you can't beat it for the price so any advice would be cool!
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Old Feb 24, 2013, 10:39 AM
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Denmark, kbh
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Originally Posted by jfrederick View Post
First off love the canard idea! My question is what's the best method for launching these?...
Well, I didn't try mine without the canards, but hand launching is straight forward: 40-60% throttle, healthy throw into the wind, 30 deegrees upward, and off she goes. If you are skimpy on the throw or there is no wind, the plane will dive some feet before picking up speed.

It will also require more rudder movement just after launch, so I use a dual rate switch, reducing throw to 30-40% for normal flight.
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Old Feb 24, 2013, 01:14 PM
you can always go faster!
jfrederick's Avatar
United States, IN, Clear Lake
Joined Jun 2011
33 Posts
Quote:
Originally Posted by mike_o View Post
Well, I didn't try mine without the canards, but hand launching is straight forward: 40-60% throttle, healthy throw into the wind, 30 deegrees upward, and off she goes. If you are skimpy on the throw or there is no wind, the plane will dive some feet before picking up speed.

It will also require more rudder movement just after launch, so I use a dual rate switch, reducing throw to 30-40% for normal flight.
Hey thanks! Just need better weather lol!
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Old Feb 24, 2013, 09:24 PM
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Anyone here have a stryker C version? I just ordered complete air frame which is very much like my radjet only with a 37 ich wing span and i will be using a 2200 3s and possibly 4s also... i need a good motor from hobbyking... i will be using a 6x5 or 6x6 or 7x5 or 7x6...I also asked in the stryker threat but no one respons . Anyone here have good motor choice for this plane...i want it to be fast 90-100 plus on 3s if possible..thx..
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Old Feb 24, 2013, 09:29 PM
DJO
Custom FPV Setups
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United States, CT, Stafford
Joined Oct 2011
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Quote:
Originally Posted by jfrederick View Post
First off love the canard idea! My question is what's the best method for launching these? I plan on making a catapult but I am concerned that with the prop being in the back that the ring would hit the prop. I finally was able to launch it underhanded with some success but the esc died(stock) and it nose dived into the ground :/....I love this thing and you can't beat it for the price so any advice would be cool!
You don't really need a catapult to launch this. I just put mine at full throttle while holding it by the end of the wing and give it a good side arm throw... works fine. Sure, it dips down a little bit on the bad throws but instantly picks up speed and gets going.



Dan
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Old Feb 25, 2013, 12:26 AM
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Originally Posted by DJO View Post
You don't really need a catapult to launch this. I just put mine at full throttle while holding it by the end of the wing and give it a good side arm throw... works fine. Sure, it dips down a little bit on the bad throws but instantly picks up speed and gets going.



Dan
Hey Dan i tried a 6x5.5 apc prop today instead of stock prop which seems to be 5.5x5 and when i landed motor and battery was much hotter and i'm sure esc was also...yes it went a little faster i think but the extra heat is something i can live without..i am surprised your stock motor can handle that size prop...but it is quite a bit lower kv i guess..so it makes sense..
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Old Feb 25, 2013, 06:10 AM
DJO
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United States, CT, Stafford
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Originally Posted by hate2crash View Post
Hey Dan i tried a 6x5.5 apc prop today instead of stock prop which seems to be 5.5x5 and when i landed motor and battery was much hotter and i'm sure esc was also...yes it went a little faster i think but the extra heat is something i can live without..i am surprised your stock motor can handle that size prop...but it is quite a bit lower kv i guess..so it makes sense..
Yeah I have recently taken the 6x5.5 off. I was flying in very cold weather so it was fine, but even my 30A ESC appeared to have overheated last flight. So I'm not going to fly it on that anymore.



Dan
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Old Feb 25, 2013, 01:53 PM
Reap the wild wind
headlessagain's Avatar
Bristol,UK
Joined Feb 2007
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Quote:
Originally Posted by hate2crash View Post
Anyone here have a stryker C version? I just ordered complete air frame which is very much like my radjet only with a 37 ich wing span and i will be using a 2200 3s and possibly 4s also... i need a good motor from hobbyking... i will be using a 6x5 or 6x6 or 7x5 or 7x6...I also asked in the stryker threat but no one respons . Anyone here have good motor choice for this plane...i want it to be fast 90-100 plus on 3s if possible..thx..
How about this motor? http://www.hobbyking.co.uk/hobbyking...00Kv_875w.html
It pulls my scratch built "Quantum" flying wing around quite well
Quantum on 4S 1800 & 7x6 prop 23Dec12 PK #16HC (2 min 0 sec)

Andy
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Old Feb 26, 2013, 05:50 PM
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Denmark, kbh
Joined Jan 2012
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Quote:
Originally Posted by jfrederick View Post
Hey thanks! Just need better weather lol!
The Radjet flies well even in terrible weather:
Mike O Canardwing (3 min 4 sec)

Although I almost lost orientation a few times. And nearly collided with the snow fence...


Today was better, but with my modded EasyStar (I can't help modding the planes):
EasyTwin low'n'slow + touch'n'go at frozen lake. Onboard cam. (1 min 47 sec)
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Old Feb 26, 2013, 06:18 PM
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Originally Posted by headlessagain View Post
How about this motor? http://www.hobbyking.co.uk/hobbyking...00Kv_875w.html
It pulls my scratch built "Quantum" flying wing around quite well
http://www.youtube.com/watch?v=eZiIYXF8fGM
Andy
Thx Andy,That motor is great..rattle snake got over 150 mph on 6s on radjet with it...i think he used a apc 6x4 prop and 60-80 esc...Buts it way more then i need ...i went with same brand motor but the 2700kv 28-36 http://hobbyking.com/hobbyking/store...arehouse_.html which is great on 3 or 4 s and will fit my stock stryker c motor mount... I should get approx 110mph on a good 2200 3s pack using a apc 6x4 or 6.5 with a 60 amp esc
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Old Feb 26, 2013, 08:47 PM
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Originally Posted by Nickuk29 View Post
First of all I would like to say thanks to everyone for so many helpfull posts on the radjet 800 it's helped a lot.

My setup.

Stock motor
Stock prop & collet
Hk digital 9g servo's
Rare earth magnets (for hatches)
Turnigy 25amp plush esc
Turnigy 3s 2200 20c lipo
Dx6i
Receiver was what come with dx6i & sat link

I set the COG at 400mm from nose tip back as suggested in many earlier threads instead of the COG mentioned in the manual.

Had the esc as far back as I could next to the motor I cut a square slot out of the back on the top of the plane to allow better air flow I am also going to cut a small slot in the canopy to allow air in because the vent holes in the bottom kept churning up grass and soil so they are getting taped up lol

The battery needed to go pretty much in the middle of the fuse between the r and the 8 in the decel's

I used the outer hole on the control horn and servo arm and had throws of between 6mm - 8mm only very small but you don't need much at all its pretty twitchy at that.

On my maiden flight wind was about 10-15mph and random gusts of 26mph not really ideal for first setup flight but I couldn't wait any longer. I'm in uk and the weather ain't been good at all lol. I set the throttle at half waited for a little wind and gave it a good toss at about 40deg and the left wing went down and hit the ground.

Only minor damage broke the wing tip soon glued back together for attempt no2

Again waited for a tad of wind held at 45deg again but gave it 3/4 throttle this time and gave it a good toss and she went up. She flew great was still a little nose heavy and the throws were spot on for elevators and ailerons. Did a few rolls, barrel rolls etc was great fun.

Landing was a bit hairy on first attempt came in like a rocket on slid about 8 feet lol on 3rd flight I tried it slightly different had it a half throttle on approach with quite a lot of altitude as it comes down quite quickly and about 100 yards out cut throttle to 1/4 glided her in and last 10feet cut throttle glided till about a foot of ground and pulled back on the sticks virtually stopped in mid air at about an inch from the ground bottom first

I will attach pics if I can figure it out and I hope this helps a few people out thought I should post my experiences since everyone else's have helped me out a great deal.

One suggestion is take a buddy with you on maiden to give it a toss for you so you have plenty of time on the sticks so you can get it trimmed out
Sounds like your madien went the same as mine.
Wounld be interested to know what radio setting people are using throws rates etc I'm on dx7 I still have not flown it.
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