[DKNguyen]

Hi everyone. I'm not a pilot or anything but need a platform to use me electronic projects in and was thinking getting an powered glider to mess around with (so I can use my motor controllers, sensors, and fit an autopilot or ground sensing sonar in it, etc).

I was thinking about just starting by trying to make a stablizer system and basically just launching the glider (unpowered) and seeing if the computer can get it to fly straight until it hits the ground.

I have a few questions. If you do just launch a glider and let it fly until it hits the ground, is it a crash or landing? Because it's be pointless to start that way if it's destructive. And how far does a "dumb" glider normally fly after it's been launched? Because if it blindly flies too far that's also unsafe. And don't gliders tend to normally fly straight anyways? I kind of need something that is stable, but at the same time is unstable enough so I can test the control system.

And since I'm not a pilot and there's a untested computer trying to control things it's also going to crash a lot. BUt I am having a hard time finding foam (ie. non-wood gliders) that have a good hollows fuselage for payload for the electronics and sensors. Does anyone know of any?

THanks.

[rkhoo]

My 2 cents worth...

<< was thinking getting an powered glider to mess around with >>

For a UAV or conrol system aided flight, I would try one without motor first.. Just one less thing to worry about until you have worked out the flying surfaces, like ruder and elevator.

<< I was thinking about just starting by trying to make a stablizer system and basically just launching the glider (unpowered) and seeing if the computer can get it to fly straight until it hits the ground. >>

Sounds good..but how do you launch it? Hi-Start (bunge cord) is possible.

<<If you do just launch a glider and let it fly until it hits the ground...it's be pointless ... if it's destructive. And how far does a "dumb" glider normally fly after it's been launched? >>

In the days of free-flight , say using rubber-band motor, all gliders are design to fly on it own after the 'motor' runs out. It usually turn left in a very slow sink. And if it hits a thermal, it can stay up for a loong time

<< I kind of need something that is stable, foam (ie. non-wood gliders) that have a good hollows fuselage for payload for the electronics and sensors. Does anyone know of any? >>

Depending on you budget, there are a few choices. The top choice are:

1. Multiplex EasyStar. Foam body and foam wing. High-payload capactiy. Hollow cockpit to place elecronic. Rudder, Elevator and motor control. Motor mounted away from nose thus less lily to get damaged. Do not need landing gear. $80

2. GWS Slow-stick. Foam wing, aluminium channel body, extreme payload capacity. Classic fron mounted motor. Rudder, Elevator and motor control. $40.

These are some comon model you can find easily in any hobby shop. Good luck.

Ronald

[DKNguyen]

Also, do you know if it is possible to detect a thermal using thermopiles to measure ground temperature (if that's even possible with a thermopile at that range)? I don't need anyhting near perfect just anything to increase the chances since they are being used as horizon sensors already.

[DKNguyen]

Oops. Looks like a double post. So I'll just stick another question here.

I hadn't planned on using the motor at the start. But I'd rather it be "motor-capable" becuase I would definately use it later on once things got established.

Really? The Slow stick? It looks so tiny. I was thinking I needed a 2+ meter wingspan type model to carry my payload. Since it's going to be some batteries and at least 3 (let's say larger than what you would expect) circuit boards and a pitot tube. You just strap everything onto the rod frame? What happens to that stuff in a crash?

What wing loading do you recommend for a sailplane?

I actually had a motor in mind because the motor controller I was building was sized to a similar sized motor:
http://www.allerc.com/g22all.htm
But...too big? THat's sort of the reason I was having trouble finding an easy to repair foam frame and wings that were large enough.