Radian - a new e-glider from Parkzone
 

Yippee! - Radian - a new e-glider from Parkzone



Guys, Parkzone is releasing a new plane in October, called the Radian.
http://www.parkzone.com/Products/Def...ProdID=PKZ4775

The Multiplex Easy Glider has been such a success, it seems Parkzone wants some of the electric glider market. It seems that a lot of the parkflyer crowd have found that gliders are another great from of electric flying. I guess the idea of getting 30 to 60 minutes on a single battery pack is just too attractive to ignore.

I spoke to a top competition glider pilot who had a chance to fly one and he said it is a pretty good performer.

Video
(Check page above for "Video/Media files" link to directly view video- BMatthews)


Edited to fix links to current Parkzone setup- B

RE: Radian - a new e-glider from Parkzone
 

aeajr
Guess the proof will be in the pudding when they come out. THere has been a lot of talk about them already and some of the beginners are asking about them. Then you get the mindset that they are not as good as the Multiplex series of models. Really bothers some that judgment is passed before they have a chance to review or even see the model before it is here. It just could be one of those that may perform well and or equal to the name brand models. Let the product and the reviews speak first. Then make an informed decison as to which way to go. I look at it as something new for the beginners and maybe some fun for long time flyers.

The video is really nice and clear. Great to see a new product finally hit the market. Now that gives another choice.

tink

RE: Radian - a new e-glider from Parkzone
 

The same thing happened when the Easy Glider came out. There were jokes and sneers from the "real glider guys". Flying beer cooler, foam toy, not a real glider.

Well that was about 3 years ago and the Easy Glider has probably introduced more people to soaring than almost any other glider before it, be it electric launched or hi-start launched. The Easy Glider flies great, is hard to break and easy to fix. It is THE trainer glider in our club. Even some of the old diehards who prefer kits have come to see how fast the new glider pilots progress on the Easy Gliders. Rather than 2 flights and a trip to the repair table, these guys are getting tons of stick time and advancing quickly.

No ParkZone, a brand that the electric parkflyer crowd knows and trusts, is going to take them into gliders. I think it is great! Whether the Radian is better or worse than the EG is yet to be seen, but it really does not matter. If it gets people to try soraing, I think it is a great addition to the market. ;)

RE: Radian - a new e-glider from Parkzone
 

I have one. I won it at the WSM in the Radian fly offs. I took it to our sailplane field Saturday and everyone got a lot of stick time on it. Horizon Hobby has a winner for sure.

RE: Radian - a new e-glider from Parkzone
 

I presume you are an experienced glider pilot, so tell us about it? How does it fly? How does it thermal? Can you compare it to a Gentle Lady, an Easy Glider or something else?

Any info/opinions would be welcome.

RE: Radian - a new e-glider from Parkzone
 

I have some sailplane experience . It thermals great, a little slow on the rudder but that can be expected with the turned up tips. The elevator is very effective. It is a lot better than the GL, just because it is more robust and the airfoil has a little under camber. The power system is way ahead of the Easy Glider. As was stated before, vertical climbs are not a problem. It is also very tough. I watched Terry Edmonds nose one straight into the ground to get a landing and did no damage. No broken prop, no bent motor shaft. Not to say you cant break it, but a 3 foot drop into the landing spot didn't hurt it. The 5 channel SS radio is a plus also. It can be used in any 2 or more channel glider or power plane. We flew it to the limits of vision and simply spun it down from altitude, which may fold the stock GL wing. Jo Grini did a nice write up on his website also. Hope this is the info that you can use.

RE: Radian - a new e-glider from Parkzone
 

Thanks. That was great!

RE: Radian - a new e-glider from Parkzone
 

Anyone got one yet?

RE: Radian - a new e-glider from Parkzone
 

Just watched the video. I have to say that it's a pretty slick looker. I wonder how long it'll be before someone uses WBPU and some form of tissue or thin glass cloth to skin it for a smoother surface. And how it'll react to the extra couple of ounces for the skinning.

RE: Radian - a new e-glider from Parkzone
 

I doubt the wings will benefit much from skinning.

RE: Radian - a new e-glider from Parkzone
 

Looks like the Radians are shipping to dealers today.

David
Currently in China

RE: Radian - a new e-glider from Parkzone
 

OK, anyone got one? I want reports!

RE: Radian - a new e-glider from Parkzone
 

Yes I've had one for sometime as preorder, its absolutely everything they say it is, nice performance and a real floater, love it...

My launch is like this, flush the elevator, not up needed at all, my elevator is actually minimum downtrim...

Use only halfthrottle a touch more on launch release, keep that nose from coming up else can turn on you, very basic stuff here, let her fly out and no turns till she goes out aways, with minimum throttles it goes right up easily...

She responds to minimum lift, even today, cold temps in Northern Illinois, right after work just before sunset, winds down below 10 MPH she found some lift and stayed elevated with power off for several minutes...

You need some space to fly this one as has a terrific long glide, I circle to lose altitude and finally zing zag at end of field prior to coming in to land, don't let the nose rise to a stall, again getting very basic here, mine is deadstick all the way, she will glide right in with correct stick, I find if I flare just before touchdown too early it pops right up for another 50 foot ride, whew, a beauty, promise you'll be pleased with this one, I have an Easy Star, great trainer, but the Radian nears high performance...huge difference, its a winner...<>..

Another strong plus, she takes winds quite well, below 10 MPH its near effortless to fly, will take up to 15 MPH and still penetrate with some downtrim, just half throttle she still goes up with ease, a nice bird indeed...<>..BEST ..<>..

Flight times even with no lift are about an hour...

My last flight as was on a sked, I had just 20 mintes, hit throttle only twice !! ..<>.

Added note, will caution on the raw beginner, its brushless motor, glider responses are amplified on this beauty, a beginner could get in trouble in short order with the pause in responses of gliders, and easy to overcontrol, I've flown gliders in the past, my first experience infact was gliders, still when I maidened the Radian, I had very minimum up elevator as on launch many of my other planes respond well this way, not on the Radian, it wanted to turn on me immediately, and once I had her straight, right into the dreaded roller coaster up and down ride, was easy for me to correct with some downtrim, but a handful for the inexperienced, again simple downtrim took care of all the issue, still suggest a starter flyer to have an experienced sailplane pilot on this one, its again a wonderful bird...you won't regret getting this one...<>..

RE: Radian - a new e-glider from Parkzone
 

Flight Report:

One of our newest flyers just got a Radian. He brought it to the filed, but is was very windy, too windy for him to fly it. However he asked me if I wanted to try. Well heck yea!

We noted that the elevator needed to be adjusted, but the easy adjusts at the tail control horn made this easy. Radio trim in center and elevator set neutral. Easy.

Plane looks nice, goes together easily. He had attached the tail with included tape. The elevator was not quite square to the fuselage. He is going to see if he can reset it.

We had about a 10 mph wind with a lot of gusts pushing up into the 15 mph range.

Check the surfaces, confirm motor control. Power off throw showed it was a bit tail heavy. We shifted the battery forward about 1/4 inch. Hand throw, power off, showed a much better glide, so I hit the power and up she went. Nice strong climb at about 45 degrees into a strong wind. I took it to about 500 feet, then power off.

I needed to add a touch of down trim to keep the speed up to penetrate into the wind. While the gusts and turbulance were tossing it around I was able to handle it. Then I noticed it was on low rates. Flipped to high and control was much better.

After a minute or so I got it going straight and level and took the hands off the sticks for about 30 seconds. She ran straight and true. :)

Landing was exciting, due to ground turbulance.

Overall first impression, this is a winner. For those looking for a first plane, an RTF trainer or a first electric glider, this will be added to the list of recommended planes.

If you are going to fly in 2.4 GHz, buy the RTF package even if you already have a 2.4 Spektrum radio. The cost difference betweenthe RTF and the receiver ready versions is $90. When you consider the cost of adding the spektrum receiver and battery, that covers the $90. If you throw the radio and the charger away, you are still ahead.

If you are going to fly it on 72 MHz and have an appropriate lithium charger, then get the receiver ready version.

This is going to be a very popular package. :D I may buy one and ship it to my Dad, so I have a glider to fly when I visit him.

Try it, you'll like it! ;)

RE: Radian - a new e-glider from Parkzone
 

It's great to have a new glider to choose from. Sounds like a real winner. I would like to know if they are going to offer a pure glider version for about $70 that I can put my own electronics in. I see that one advantage that Multiplex offers is that you can get an Easy Glider as an unpowered glider, unpowered RTF, powered glider, powered RTF or the PRO version set up for custom brushless installation. Perhaps in time Parkzone will offer as many different versions.

RE: Radian - a new e-glider from Parkzone
 

One caution on the raw beginner level, the Radian is a tad much with brushless motor and it will turn on a novice flyer unless they drop the nose on launch, also gliders have a tendency to delay on stick inputs, so an overcontrol issue, just a caution if a newbies is considering one, oh Yeahhh still get one but Please get an instructor on the maiden flights, note how aeajr made the correct adjustments prior to flight, setting trim and getting the proper COG Center Of Gravity balance....these are so important, and the landings, it floats forever so defintely have a sizeable area to fly this winner...BEST ..<>..

Note just back in, quick flight on the Radian as have to work, fly just before dawn but winds still up abit, around 8 to 12 MHP with over 15 MPH gusts, she went right up at only half throttle, slight downtrim to penetrate, managed good elevations, handles very well, however as had to leave on bringing her down gusts suddenly built up, she even did a loop, coming back downwind and turn for landing gave some more down trim and things settled, she landed with ease, its great fun, but take your time getting accustom to windy condtitions, go easy, a big plus on this one even on windy days...BEST ..<>..

RE: Radian - a new e-glider from Parkzone
 

THINGS TO CHECK ON AN RTF
http://www.rcuniverse.com/forum/m_6582895/tm.htm


If you are a new flyer be sure to check this thread before you fly your Radian.

RE: Radian - a new e-glider from Parkzone
 

2nd day for the Radian. Got a 50 min flight out of it with only a 60 sec burn to get it up to altitude (during my lunch break). This is my first glider (15 years w/ helis & 3D planes). I'm really enjoying the peacefulness of this little guy. This RTF package is going to be a big hit.
I've got my CG at the manual recommend spot (2.5"). I've tried it back to 3", although it needed a trim change it still flew fine. I'm no glider expert - where is the best CG for the Radian?

RE: Radian - a new e-glider from Parkzone
 

Most, thermal glider piltos will start to move the CG back a bit at a time over time. The further back, to a point, the more responsive the plane will be and the easier it is to read and work lift. Get it too far back and the plane becomes hard to handle.

If the starting CG is 2.5, then 3" would be a big move, but if you can handle it there and you are not having to work hard to keep the plane flying, then it it probably OK for you.

RE: Radian - a new e-glider from Parkzone
 

Thanks for the explanation Ed.
However, what I really want to know is what CG makes the glider most efficient. You see, I've never flown an aircraft as stable as this. I'm used to most aircraft flying in whatever direction you point them. The Radian will constantly correct itself (if you let go of the sticks) to an optimal descending glide path. You can push the nose over and let go.. it will level off. If you pull up, it will stall, rapidly descend and level off.
I can change the descending glide path by using elevator trim. ie i can speed it up or slow down the descent rate (until it constantly porposes thru stall maneuvers).
If I adjust CG - i can maintain same glide path by re-trimming out the elevator. I would think with an aft CG - the horizontal stab and elevator would create more drag (because it is fighting from sinking). Same goes for a forward CG.
I would imagine a perfect CG would yield optimum lift/drag ratio..which, I would imaging is what you are looking for on a thermal duration glider. Right?
With that said.. what is the optimum CG for the Radian?

RE: Radian - a new e-glider from Parkzone
 

It is true that TD sailpalnes tend to be more stable than aerobats. That stability allows the glider to fly and to hunt for lift with minimal input from the pilot. Every time you move the sticks you create drag which saps energy from the plane. However if we get too stable the plane won't respond well to lift. The glider might fly right through a thermal and we may not see the effect of the thermal on the glider. So there is a midpoint we seek.

BALANCE AND SAILPLANES

There are many points of view on balancing sailplanes. I will share some common or personal views.

1) As stated above, once you have the feel of the plane, start to move the CG back. A more forward CG makes for a more stable plane, but one that will not be as responsive or sensitive to lift. Too far back and it will be had to handle and you will be constantly correcting. You want something in between. Most plans and most RTFs are set up a little nose heavy to make the planes stable, which is best for inital flights or beginners.

2) A forward CG, being a little nose heavy, forces you to trim in some up elevator to get the plane to fly level. This leads to a very self correcting behavior. If the plane goes into a dive, it will pull itself out, for example.

This will also cause the plane to pull up hard under power. While most e-gliders I have flown will have some tendancy to want to raise the nose under power, if the glider wants to go into a loop, you have a fair amount of up trim on that elevator and this might be due to being nose heavy. You can read this using the dive test.

Take the Radian high, then turn the motor off and be sure the prop folds.

Get it flying level, smooth and stable into the wind.

Now, put the Radian into a dive, maybe 45 degrees degrees.
As the glider picks up speed, any up or down trim in the elevator will be magnified by the higher speed.

If it is nose heavy, that up elevator trim will cause the plane to pull out of the dive quickly.

If the elevator is neutral, the plane will come out of the dive very slowly or will hold the dive till it hits the ground. DON'T LET IT HIT THE GROUND! I actually had someone watch it fly right into the ground. He was watching the dive and looking for the pull-out which never came.

If it is tail heavy, the plane will tuck, that is the dive will tend to steepen. Be sure to pull out before something bad happens!

When I tune my gliders, I shoot for a neutral dive test. From about 300 feet, the plane will hold a 45 degree dive or come out slow enough that I may have to pull it out or crash.


3) Wing incidence - the angle relationship between the the wing and the h-stab.

If you have stab/elevator type tail, as the Radian does, and you have to put in noticeable down trim (looking at at the stab/elevator relationship) to get any kind of neutral dive test, chances are your h-stab is not level to the wing. If the stab is up in the back, this gives you a constant up elevator effect. Planes that have fully flying stabs, where the whole surface moves, don't have this issue.


Some other resources.


Performance Tuning Gliders - This is outstanding!
http://forums.flyesl.com/topic.asp?TOPIC_ID=227

Gordy on Balancing
http://forums.flyesl.com/topic.asp?TOPIC_ID=255

Test Flight Procedures
http://forums.flyesl.com/topic.asp?TOPIC_ID=226

RE: Radian - a new e-glider from Parkzone
 

Very Nice Info, I've loved sailplanes tho far from a competitive flyer, but listening to them and veiwing some of the excellent flyers, slight trim adjustments are likely going on continually, if you lose lift you need to find another and actually need some penetration to reach the next lift zone, so near floater setting isn't always what you want, you do want to arrive to the next lift, I personally would dart right thru them but they know immediately when they reach one, movement of the wingtips, slight change of speed, gives a clue...takes awhile but after several flights the stronger lifts will be quite evident, the Radian will respond to lighter lifts, so its again a winner as I've hit lite lift with this babie near sunset...<>.. have fun...<>.BEST ..<>...

RE: Radian - a new e-glider from Parkzone
 

Thanks for the excellent explanation and links on setting the CG for thermal gliders, Ed. Much appreciated. :)

I've noticed the main wing has several degrees of positive incidence (it also has a down-turned bottom foil - neg. camber?). I've never flown an airplane that didn't have a symmetrical or semi-symmetrical airfoil. I imagine this is what gives the Radian the excellent lift to drag ratio at lower air speeds.
However, your suggestion of putting the Radian in a 45 degree dive to check for elevator trim doesn't sound like it would apply to the 'Radian' type airfoil - would it?

RE: Radian - a new e-glider from Parkzone
 

Here is a pic of the incidence of the main wing. Notice the camber? at the trailing edge:


http://www.smugmug.com/photos/416850297_bJSEA-M.jpg

RE: Radian - a new e-glider from Parkzone
 

We are not evaluating the wing, we are evaluating the elevator. This will work on any wing type, as far as I know.

I only have one plane that does not have an airfoil similar to this and it is a semisymetrical aerobatic glider. The flat, near flat or slightly under cambered wing is common on thermal duration gliders. Higher lift with moderate drag. Optimized for low speed flying. On a plane like this, 40 mph is really moving! It will probably do very nicely at 10 mph in calmer air. I don't clock my planes so I am guessing. But my Easy Glider, with the brushless upgrade, tops out at 45 mph and, for that plane, it is really moving.