building a glider

hello183

Active member
I took the glider for another flight, but it had an encounter with a tree.
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Luckily only a portion of the leading edge between the ribs broke and I haven't been having trouble fixing it. It looks a bit crooked in the picture, but it is just the camera.
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When it gets warmer, probably next year, I will take it to a bigger area where it hopefully will be able to reach some thermals and get longer flights. If I could launch this into a thermal and get it high up, it glides well enough that I could definitely lose it. I measured one of the flights and I think it got a glide ratio of between 16:1 to 20:1. It might be able to fly better if i change the wing incidence.
 

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Piotrsko

Master member
A dethermalizer needs to be very agressive, almost to the point of crashing to overpower the lift gained in a thermal. Typically, people try to cause a stalled spin which is gentle enough to not break things. Spoilers of at least 10% wing area might be enough, but I have seen thermals strong enough to carry porta potties away. Loosing your plane in a monster thermal is a rite of passage
 

hello183

Active member
It would be hard to cut off the control surfaces or the wing dowels, which are things I'd need to do to add a dethermalizer system like the ones in the video. But I heard of a pop up fuselage dethermalizer. What do you think about a system that disconnects the nose cone for the dethermalizer?
 

hello183

Active member
I was thinking that if I disconnected the nose somehow, the center of gravity would change and it would come down. But to not lose the nose I'd have to attach it with a string or something. Is there a way I could add a parachute while keeping the weight down?
 

danskis

Master member
Well the parachute was a dumb idea. In a large thermal it would probably make the plane go UP. Your idea is better
 

hello183

Active member
I was thinking of designing a bigger glider with radio control. I won't do that now, because I want to learn how to fly first. What carbon fiber tail boom would you use for a glider that is big, but meant to go quite slow? The wingspan right now is a bit more than 2 meters, and the fuselage is about 1.4 meters. I was thinking about one with a 10 mm diameter. I couldn't find any tube long enough online. Where would you look for it?
 
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danskis

Master member
10mm sounds perfect. How are you going to get it in the air? Hi sart, motor, or throw it. A 2 meter glider is perfect for learning how to fly RC.
 

danskis

Master member
You have options with the boom. You can make a nose that goes from the back of the wing forward basically a box out of foam board or balsa or a combination of both. and use the CF boom for the back. Or you can buy two shorted booms and splice them together.
 

hello183

Active member
I was thinking about using a motor, but I may just use a towhook. I was going to build a balsa pod in the front, but even with that, the boom would need to be 95 cm. I could only find 50 cm booms online. How could I splice booms together?

Also, should I put this discussion in a different thread?
 

Piotrsko

Master member
There's also fishing rods and arrow shafts. The arrow shafts have a common diameter that uses a readily available carbon shaft as a splice, Saw a 9 ft fly rod at the local Goodwill for $5 that needed the ferrules taken off the lower half
 

quorneng

Master member
I use tapered glass fibre fishing rods as tail booms.
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ct that there are tapered actually, The fact in part, matches the bending forces so reduces the deflection for a given weight. With a "V" tail the micro servos are mounted in each tail plane and the wires run up inside the boom.