So I have found a new place to fly, actually closer to my house, and quieter. I can take off from the street, but have found most of the grass is great for takeoffs if I had larger wheels. The grass, however, lets the Radian Pro have a soft landing, much more so than the last place which was much worse grass conditions. I have had about 10 flights, and I'm starting to quite like the Radian Pro. Overall, the plane looks great, though the decals on the bottom of the wings could be better. It seems that these decals hold the ailerons on, but not sure exactly (don't want to find out either). The tape holding the horizontal stab is another area I wish was better, but it works. Flight wise, the plane has ample power, but it isn't a plane that likes power as it tends to want to bank under power, and you have to play with aileron to stop this, or the plane will flip. This brings another issue, if the plane flips and dives, it gains negative lift in the wings, and you can actually see it happening. Now I suppose it wouldn't be easy but stiffer wings would help immensely.
During glide, I find the Radian Pro likes half flaps. This gives the plane lift but avoids more potential for stall that full flaps. With this I flew for 30 minutes in glide after a 30-40 second climb. Along with some thermals around the pond area. No flaps gives a lot less lift, but allows more speed. With more speed the thermals are skipped over
I used no flaps when I picked up speed and tried some inverted glide. While getting inverted is slow and usually fails, it actually flies stable inverted. I wish ailerons had more authority, but the way the servos are, it would require ripping them out and installing longer horns. Rudder has good authority, as does elevator. Occasionally I used full flaps and allowed to plane to essentially hover, which was fun. On landings I used full flaps as well to allow slight dive to clear pond but keep speed low, and this works well.
Overall a good plane, but due to wing flex in higher speeds and dives, which requires yanking on elevator to pop it up, beginners should go with the lesser wing Radian I presume. Even so, flight is gentle and predictable.
Rather than trying to go inverted with the ailerons, why not try
adding power and doing a half-loop. Just cut the power on top
and feed in some down elevator to maintain the inverted flight.
I could have done that, but I actually was trying to do manoeuvres without power, and keep it up as long as possible while doing various things. If the wing was stiffer, I probably could have dived to get speed and then pull up and settle out on the top of the loop, but as soon as the plane gets speed in a dive, the wings really flex when trying to pull out.
Yikes, haven't made the wings bend that much...although don't think it will ever get to that point.
Get some 8mm Square Carbon Fiber tube, and cut a Tight slot about 1/3 back from the leading edge on the bottom side of the wing, and epoxy in the 8mm CF brace, then cover it with some clear packing tape, that will make that wing nice and solid so you can fly it like you stole it LOL, Take care and have fun, Chellie
PS . The CF does not have to go all the way from wing tip to wing tip, just about 2/3 of the wing in the middle, in the pic below, i uses a Slow Stick square fuselage for the wing brace with a 9mm foam wing, yea, its solid for sure
Have a short video of the Radian Pro. The video would stop recording suddenly, and this is my longest video. I think the SD card may be too low of a class, or not large enough space. What I didn't like was the majority of the vid was climbing, as I was soaring for a good 15 minutes with no power.
As I noted I have a Commander EP40, which is a "Pattern style" model aimed at precision aerobatics.
That does just fine with the EPO flexing in higher G maneuvers. Even flexing its tips up from flat to 45 deg isn't hurting the ability to do the precision maneuvers.
It looks strange until you get used to it... but its not hurting anything.
Stiffening the wing will add weight and that WILL affect performance.
I was noticing some sort of negative lift when the wings flexed, such that in a dive, the Radian would want to dive more, and a hard throw on the elevator was needed to bring the plane level. I'm not even doing any extreme things, just a simple dive to pick up speed.
That may be an effect of washout and speed resulting in further twisting the wing.
Putting in a simple spar won't stop that. It would require essentially fiberglassing the "D tube" section of the wing to prevent the twist.
It could also be fuselage flexing.
Nothing you do to the wing would affect that.
You can try adding the spar... I don't think its going to help the way the airplane flies.
So essentially a design flaw, or at least I'm asking to much from the design. It's a shame, I've seen gliders like the blaze, and it seems the radian pro can't do any of what it can.
Have you placed this model on a stand or support, and eyeballed it from five or ten feet in front? Check for unwanted twists in the wing, as fhhuber indicates. I've got a gadget that is used for this purpose to measure wing twists via laser beam. So sad, this unit is no longer available.
I picked up a Vyper model (FREE!) from a club member a few months ago. First maiden flight, the model violently rotated to the left. Full right aileron trim got it flying level.
At home, I did the eyeball trick, and found the left aileron was warped up, the right aileron warped down. It was obvious. That wing measuring thing showed their was a four degree twist up and down at both aileron wing tips, when the center of the aileron was centered at the fuse. Five minutes with a monokote iron, and all is good.
Retired and the days are just too short, busier than ever!
Yep, I realize that now. I still like the Radian, just wish I could push it a tad bit more. I don't want a glider that does insane high g stuff, but one that likes being under power more.
The Radian is not meant to be pushed. It's not a stunt plane. It is a finely tuned sailplane whose purpose is to find subtle and not so subtle lift so it can gain altitude without the use of the motor.
It was never meant to fly under power. The motor is a launch device only. What you want is that profile 3D plane Chellie posted. You're trying to use a Ferrari to tow a 30' boat and downing it because it can't do it. It's a LOUSY car. Can't even tow a 7,500 pound boat and trailer.