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another rookie seeking help with radian

#1
Just started flying 2 months ago with hobbyzone delta ray. I flew it successfully some and crashed it some.
Wanted something different so I got a parkzone radian. I expected a sailplane to be slow and gentle but to ME it seems fast and hard to fly.
Main problem is on launch, first time I put the throttle wide open (is that always correct?) and it did a loop right away. My first loop but it was an accident and I was out of control.subsequent launches are full throttle and less elevator but I have trouble with the first part of the flight...wants to go straight up so fast and loop and my corrections are probably to much too quickly and end in a crash.
Is there some advice to getting this thing safely to a good altitude where I can get used to it?
Thanks in advance.
 

earthsciteach

Moderator
Moderator
#2
Try launching with less throttle. The Radian will fly slowly. Give 3/4 throttle a try with controls in the neutral position. You can increase throttle, if necessary, to climb to altitude. Just do so gently.
 

stay-fun

Helicopter addict
#3
Sailplanes like the radian put the nose up at full throttle, so what you're experiencing is a property of this specific plane. I suggest to launch at half throttle.

Also, do a hand-toss without throttle (a glide test). A radian should glide quite a bit, like 30-50 meters or so (even 100 if you do it well). Without control input, it should just glide more or less level. If it puts the nose down, your CG is too far in the front. If it wants to put the nose up and stall, the CG is too much toward the tail. Balance it out by moving the battery.

Hope that helps.

(BTW I have never flown a radian, so if anyone says I'm talking BS, trust that person instead :p )
 
#4
Thanks

Super helpful replies. I had actually read somewhere that to launch an RC you always give full throttle and full El...it worked for the delta ray but now I'm starting from scratch I guess.
Maybe someone with the radian will reply as we'll.
 
#5
Another thought

Perhaps my delta ray seems so gentle is because I fly in beginner mode instead of intermediate or advanced. The plane can only go up or down or roll within a small envelope.
 

themajik1

Monkey/Bear Poker
Mentor
#6
Super helpful replies. I had actually read somewhere that to launch an RC you always give full throttle and full El...it worked for the delta ray but now I'm starting from scratch I guess.
Maybe someone with the radian will reply as we'll.
tglenn,

You should not normally launch a plane with full throttle as depending on the plane a few different things can happen.

But first, lets make sure your CG is correct. The correct CG for the Radian is approximately 2.5 inches (63mm) from the leading edge of the wing measured at the fuselage. This plane has plenty of lift and should be able to launch around half throttle give or take.

The control surfaces should be neutral or as close as you can. When giving the Radian throttle it should climb an less throttle it should either hold altitude or slowly lose altitude.

This should help you in launching the Radian and be able to get it in the air without too many issues. Then get it up to a safe altitude and trim out for your preference.

Good luck, and I am sure that you will love the Radian and get very proficient at flying it very quickly!
 

stay-fun

Helicopter addict
#7
Perhaps my delta ray seems so gentle is because I fly in beginner mode instead of intermediate or advanced. The plane can only go up or down or roll within a small envelope.
Absolutely fly your delta ray in the more advanced modes. You'll learn a lot!
 

joshuabardwell

Senior Member
Mentor
#8
Super helpful replies. I had actually read somewhere that to launch an RC you always give full throttle and full El...it worked for the delta ray but now I'm starting from scratch I guess.
Maybe someone with the radian will reply as we'll.
I would say that if you have to launch with full throttle and full up elevator, the plane is too heavy and trimmed wrong or has a bad CG. I launch my Bixler at about 3/4 throttle, but I used to launch at about 50-60% throttle before I loaded it down with FPV gear. It requires only minimal up elevator--in fact, excessive up elevator causes it to stall. If your Radian loops with full up elevator and full throttle, then it sounds like it has ample power for its weight.
 

BWX

Junior Member
#9
My advice is to get the CG at 2.75" back at wing root (Google or search CG and wing root if you don't know what that means)..

I think my Radian flies great right there, but stock CG is 2.5", you could also try that if you want. You can move battery around, or add weight to fuse under tail. I use a penny on each side stuck on with clear tape and it works just fine.

Also you may need to adjust mechanical elevator trim with some down trim if it is still trying to go up even with half throttle or porpoise when just gliding with CG correct. Don't count on elevator lining up with horizontal stab exactly. That may not be correct for your Radian, they all may be a little different given that they are foam. All trimmed out, my elevator is down a degree or two compared to stab but it flies great like that.

Do a dive test and try to make it so that it doesn't constantly try to keep going back up when letting off elevator stick in a 45 degree dive. Maybe allow for a little bit of a curve to your dive so it tries to level out just slightly.


Once you get it working good, and then climb with full throttle, it may require some down elevator to keep from looping or climbing at an increasing rate. That is normal, it's just the way these things are. If you get CG really far back (like past 3", or maybe even 3.25 to 3.5", and then adjust decalage, you might be able to get rid of that tendency, but I wouldn't worry about that until you become much more experienced as an RC pilot in general.