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-   -   My feelings of the Radian Pro (http://www.Wattflyer.com/forums/showthread.php?t=73697)

thepiper92 05-05-2014 07:23 PM

My feelings of the Radian Pro
 
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.

Heli Jim 05-05-2014 08:05 PM

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.

thepiper92 05-05-2014 08:11 PM

Quote:

Originally Posted by Heli Jim (Post 947470)
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.

fhhuber 05-05-2014 08:16 PM

Its just the EPO flex.... You can bend the wings a LOT without worrying.

thepiper92 05-05-2014 08:17 PM

Yah, certainly is scary looking though.

fhhuber 05-05-2014 08:26 PM

My Commander EP 40, also made of EPO, is supposed to have straight wings. In a tight loop it can look like it has an elliptically curved main spar making the tips point almost 45 deg "up"

These EPO foam airplanes just about can't be stressed to the point of breaking in flight.

thepiper92 05-05-2014 08:28 PM

Yikes, haven't made the wings bend that much...although don't think it will ever get to that point.

thepiper92 05-15-2014 08:31 PM

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.

https://www.youtube.com/audio?video_...&v=B5WGRFYgVNQ

CHELLIE 05-16-2014 11:32 AM

Modify That Wing
 
Quote:

Originally Posted by thepiper92 (Post 947476)
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 :D :D :D 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 :tc:

http://www.wattflyer.com/forums/atta...9&d=1227956204

http://www.rcfoam.com/carbon-fiber-s...ube-p-843.html


http://www.wattflyer.com/forums/show...katana+chellie

thepiper92 05-16-2014 05:03 PM

May have to try that, thanks Chellie. It would be nice to get that wing stiffer.

fhhuber 05-16-2014 06:39 PM

But... its not broke... The EPO can be allowed to flex and its just fine.

If it was the foam used in those flat foamies it would snap at less than 1/4 the bend but the EPO is almost like rubber.

Let it bend its fine.

You can reduce the bending with a strip of clear packing tape or strapping tape on the bottom at appx 30% to 40% chord. But even that is overkill.

thepiper92 05-16-2014 06:49 PM

The flex alters the flight performance it seems.

fhhuber 05-16-2014 07:18 PM

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.

thepiper92 05-16-2014 07:22 PM

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.

fhhuber 05-16-2014 08:30 PM

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.

thepiper92 05-16-2014 08:39 PM

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.

fhhuber 05-16-2014 09:10 PM

Its a EPO model... not a high end competition model.

If you want one that will do 300 mph+ and pull 100 G without visible flexing... they make high end carbon fiber "dynamic soaring" models for that.

thepiper92 05-16-2014 10:16 PM

No not to that extreme, but basic things like the blaze does. Oh well it's still fun floating around for 30 minutes on one pack

kyleservicetech 05-17-2014 12:08 AM

Quote:

Originally Posted by thepiper92 (Post 948536)
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.

Not a bad price for a model that just needs a receiver and battery pack.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXACFW

kyleservicetech 05-17-2014 12:11 AM

Quote:

Originally Posted by thepiper92 (Post 948536)
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.

thepiper92 05-17-2014 01:42 AM

The wings seem true, as do ailerons. The plane doesn't enjoy being under power too much. Just diving is an issue

Larry3215 05-18-2014 01:57 AM

It's a sailplane that happens to have a motor in the nose so you dont have to cart around a winch or hi-start.

It's designed to power up to altitude and then shut the motor off - and leave it off - while you soar.

If you want a model that does better at powered maneuvers, then you need a different model :)

thepiper92 05-18-2014 02:33 AM

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.

fhhuber 05-18-2014 03:15 AM

Probably more on the lines of a "Hotliner"

http://www.espritmodel.com/sailplanes-hotliners.aspx

These are somewhat higher priced ones. There are others available at lower cost. They CAN slow down almost as slow as the Radian and ride mild thermals, but they rarely get flown that way.

thepiper92 05-18-2014 03:49 AM

Maybe I'm contradicting what I want from the radian, but if hot liners are not used to float around, what is the benefit it having the wingspan instead of say a quick sports plane? Do they achieve all of the speed without the motor? I saw the blaze which is closer to a hotliner, and the throttle is on most the time it seems.


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