BOT glow uav

[stevievb]

I wanted to hear anyones thoughts, ideas, comments, or suggestions about converting a bird of time to glow and then use it as a uav. I was thinking about a .60 or .40 mounted right over the cog above the wing.

thanks

[lvspark]

Anythings possible if you put your mind to it! Give it a shot!

[Peteohms]

Just go electric. Technology is there now.

[stevievb]

I was thinking about electric but was not quite sure how it would match up to glow endurance?

any recomendations for an electric setup?

[djklein21]

Why?

[kd7ost]

I was thinking about electric but was not quite sure how it would match up to glow endurance?

any recomendations for an electric setup?

You'll have no shortage of pilots telling you that Electric is necessary. As much as it has advantages in some areas, it falls short in others. Most of them have not likely flown glow or gasoline planes and it's a mystery to them. Or, they just regurgitate what they've heard. All the myths and legends as it were.

The best thing to do first is define a mission for your UAV and a workable budget. The budget should consider what you have on hand. Electric is not cheaper than wet fuel by a long shot. And even if you get the best set up for your trainer out there, you might struggle to get 20 to 30 minute flights with good throttle management on a calm day. If that’s acceptable, then electric is a quiet clean way to go. Don’t forget turnaround time with charging modern LiPo’s on the ground. With the best charging rate allowed on the most modern batteries, it can take an hour or more to recharge a pack that has been flown till empty. Measure that with me putting a quart of 2 cycle gasoline in my gas plane, taking less than 3 minutes to pump it in, flying at full cruising speed, 50 mph, for a full hour before I have to land and you can see those two don’t even compare. You can have extra batteries though to keep faster turnaround time with electrics. If you want to fly non stop all day long you’ll need about 4 to 6 packs at close to 100.00 each plus chargers at 75.00 or more each, (They’ll have to be high current LiPo chargers) and you’ll probably have to keep you car running just so the alternator will keep the automotive battery from going dead if that’s your charging current source. Oh, and the cell is probably only good for hundreds of charges before you have to recycle it and replace it. Ouch on the cost. My Gas powered Pegasus1 plane has traveled in excess of 2,200 miles over the last few years with never a shutdown or an engine or battery pack rebuild. You can’t beat the cost, reliability and simplicity of a magneto ignition, gasoline engine.

I am of course talking extreme examples. Most people have no need, desire or reason to fly all day long unless you’re doing a specific mission.

What is your cargo? How much weight do you need to carry? How long do you need to stay aloft? Things like that are helpful to answer your question.

I fly Glow, Gasoline and Electric. But I choose glow just for fun flying small planes where I want superior power to weight ratio. For my UAV/Aerial photography planes, I use gasoline or Electric. Glow engines blubber all that messy lube. And even though all technologies are pretty highly refined and work incredibly well, the reliability of glow is less than gas or electric. I’ve had dead stick landing with glow before while there was plenty of fuel left.

The only time I’ve dead sticked gas or electric planes is when I flew till the fuel tank or battery was empty.

Like Ivspark says, you can do anything you want. Big manufacturers out there are using all three technologies. Skilled people know it can be done. It’s up to you to learn the quirks and variations and make your own project come to life based on your desires, needs and budget. Nothing wrong with getting your head outside the box. Or in this case several different boxes. ;)

Dan

[macboffin]

Above endorsed! BUT if you are thinking about "Bird of Time" there are no small enough gas engines available, unless you want to get into conversions; diesel will give you duration, quiet too. A .25 or .30 size would be enough for the plane you fancy, unless you are going to mount a ton of gear in it.If you mount the engine in a pod over the wing, you would need some upthrust, or have to fly around with a lot of up trim on ele. Certainly a viable way to go though.
Much better to design an airframe for purpose though.
Raises yet again a point I have often made, a UAV is an aerial camera platform, and conversion of a design intended for another purpose can come unstuck!
Bird of Time is a sailplane, structure may not be up to flying at faster speeds and higher weights; you could pull a tight turn and see the wings clap hands overhead.
Expensive hole in the ground!