Radian

[doctormike]

I drug out my old Radian, dusted it off and took it to the field. Years ago, I installed spoilers on it. They work great. I had a blast practicing spot landings using my spoilers up and down to control the decent. Doc

[xviper]

Can you show us a picture of the spoilers? Our little flying groups has many, many Radians and each of us have gone through more than one. I've always wanted to install spoilers on my Radian. My Radian XL spoilers work so well as do the ones on my Mystique. One guy at my field cut out some flaps on his Radian and he swears by them.
I've installed spoilers on my Opterra and my old X8 wing. They work so well, I'm surprised they don't come like that.

[doctormike]

They are very simple. No fancy mechanics, and work great. Hold your wing up to a light to see where the spar is. You don't want the servo over it. Cut out a 2"x 9" rectangle about 1/16"deep at the highest point of the wing and about 8" out from the fuselage. They shouldn't be to close or they will disturb the air flow over your stabilizers. Cut out a hole just deep enough for your servo, centered in the length of the rectangle. The servo arm needs to center very close to the hinge, but not outside the cut. The arm will be pointing towards the trailing edge. Install your servo with the arm on it. Make your spoilers from 1/16" bass wood. I forgot...important! Make your spoilers first and use them as a template to make the cut out in the wing for a perfect fit. I spray painted my spoilers white. With the servo arm down, place the spoiler into the indention and use 3M packing tape for the hinge. The packing tape hinge will actually hold the spoiler down, but I installed light magnets, also. Now, adjust your servos with your transmitter flap setting. The servo arm simply pushes the spoiler up...no mechanical attachment. Wind and the tape pull the spoiler back down and the magnets hold it. You don't want your magnets to be too strong. The only difficult part of this is making the bottom of the indention nice and level. I used a Dremel with a sanding wheel. Sorry I'm not good about sending pictures. I'll try...I have done it before. GOOD LUCK!!! Doc

[xviper]

Thanks for the explanation. It sounds like the same way I did them on my Opterra.

[doctormike]

Yeah, good. No need for any mechanical contraption. Doc

[Billy S]

The new version

[xviper]

The new version

?????? :Thinking:

[doctormike]

We just went camping up in a high mountain valley (9000 ft.) where I flew my Radian. The thing just kept climbing (no throttle) 'till I had to deploy the spoilers to keep it from climbing. It was a speck! After an hour (boy was my neck sore) I brought her down with full spoilers. Well, I'm afraid my depth perception isn't what it once was. An 80 ft. Ponderosa pine reached out and grabbed it! Thankfully the winds had mercy on me and, later, blew it out of the tree. A few repairs and she's ready to go again. Boy!!! What fun! Doc

[Slo and High]

I bought a 2 meter Radian and I read this thing don't want to land.:Straight-Face: I read your descrition of the spoilers you installed and what a great and simple idea it is. I do have a question about the size of the opening and I assume the spoiler is the same 2" X 9" size as the cut-out mentioned. I have seen other spoilers in google searches and none looked that large/tall (2"), when deployed.
Because of the working-design of this spoiler, is the 2'' dimension needed for the servo arm to work correctly? Did I get that size incorrect?
I am thinking this spoiler will not go vertical but maybe open to a 45 degree angle. (???)
I am getting back into RC. This is my first post, "this time around". I was in RC from 2000 to about 2008 and like a fool........ sold everything:Crying: At 76, I am moving slower so I want my aircraft to be on the slow side too. My RC club's field does not have as much runway length as some others so I thought spoilers would be perfect.

NOTE: Attached are a few photos. The tall, electrified sailplane I built from a kit from Skybench Aerotech, Ft. Wayne IN., their XL Big Bird.
Indy Bob

[xviper]

I bought a 2 meter Radian and I read this thing don't want to land.:Straight-Face: I read your descrition of the spoilers you installed and what a great and simple idea it is. I do have a question about the size of the opening and I assume the spoiler is the same 2" X 9" size as the cut-out mentioned. I have seen other spoilers in google searches and none looked that large/tall (2"), when deployed.
Because of the working-design of this spoiler, is the 2'' dimension needed for the servo arm to work correctly? Did I get that size incorrect?
I am thinking this spoiler will not go vertical but maybe open to a 45 degree angle. (???)

Take a look at the Radian XL and the type of spoilers it uses. They aren't that big and when deployed fully, the plane drops very effectively and is very controllable. Something that size would work extremely well for the regular Radian. Unfortunately, Eflite has discontinued the sale of the spoilers as a separate part. HobbyKing makes a set of similar plastic spoilers that would work for the Radian. They also make a set of metal ones with self contained actuators but those ones are a bit heavy for the Radian.
Having said that, the Radian, as is, can be landed quite well. You just have to plan the approach such that it loses adequate altitude before getting to the end of the landing strip. We've got many Radians (over 7) at our field and nobody has spoilers or airbrakes. They all land fine.

[doctormike]

Hi, Slo and High. I tried smaller sizes and gradually worked up to this size, which works great. You could try less than 2" with a shorter servo arm. Good luck! Doc

[Slo and High]

Thanks guys,
I did not check back so I am late getting back.
I have to check my profile. I thought I would receive and email when I get replies.
The main reason I was thinking of spoilers was the fact that the club closest to me does not have as long a strip as many others do.
I am sure I will be fine by losing the correct altitude before the start of the strip. If it does not work out ........ I will look into spoilers at that time.
Thanks again,
Slo and High. Bob

[doctormike]

Yeah, but, practicing landings with spoilers is just a lot of fun. Doc

[toothbuzz@hotmail.com]

I've found that as I near touchdown bumping the throttle just enough to get the prop to extend acts as an airbrake. Just make sure to kill the throttle as the glider touches the ground.

[xviper]

On the topic of spoilers or airbrakes on very floaty, high lift sailplanes, I have tried the windmilling prop and compared this to the use of the former devices. Windmilling the prop does have some decelerative effects on All planes, including ones with folding props. By contrast, the effects of airbrakes/spoilers in slowing down and reducing altitude of a plane far exceed that of a windmilling prop. Doing short finals and spot landings is easily accomplished and very predictable. Lacking brakes/spoilers, windmilling is an option.

[Grantham Kid]

I bought my Radian a new set of wings because I wanted to experiment with the old ones. I had hobby king spoilers on them.
I glued them together and fitted them to my Phoenix 2000 and it made a real glider out of the Phoenix. Much better performance. I had to pack the leading edge up 3mm and of course build in the top of the wing to suit the Phoenix shape.
I have never fitted the original Phoenix wings since. They are in my shed and still like new.
Not a good pic, but me with my modded Phoenix 2000 with Radian Wings and Spoilers. You can see the Biggy mounted behind the wing.