Good Blimp Electric Engines/Props?

[tschwartz1]

Hello All...

I am in the process of building a blimp with some special nav/sensor/onboard computing/photo stuff on it. It's for outside and will be between 18-22 ft. I have heard all the size issues so am working through those.

I am debating on propulsion systems. These are my ideas I am kicking around.

1) Traditional Props mounted on each side.

2) Ducted Fans like used in the "Jet" planes.

3) Ducted Props. These I cant find anywhere out there.

Any clues for speed, power, efficiency, battery life, coolness factor, etc?

Thanks
Tony

[Majortomski]

I run ducted props just to try to keep peoples fingers out of them. Nuther gentleman here on this thread that also produces blimps has switched to larger diameter, slower moving props for better efficiency.

[tschwartz1]

Where can I find Ducted Props? I havent seen a single source for them.

Thanks
Tony

[Majortomski]

The blimp in the avitar uses speed 400 and wood TF 6x3 props. I vaccuuform my own ducts.

[Majortomski]

Looking at your post I'd go with two brush less motors turning un ducted 10 or 11-inch props. Trouble is the size of your blimp. Unlike a full-scale blimp, which develops a lot of lift off the shape of the bag, our sized blimps are more of aerodynamically stream lined helium balloons. The 13-foot bag in the picture is unstable at high speeds (6, + mph) even with the proportionally large fins shown, it will "tuck" left and right with the least provocation. I think for outside stable work you're either going to need a better finess ratio or an autopilot to dampen your swings before they happen. Then do you intend to hover? If so you'll need a tail rotor for calm days, there isn't enough airflow.

On second thought, if your package weighs less than 3 pounds I can sell you one of mine for a lot less cost and trouble you're looking at. If we switch to Lipo's you can lift 5-pound mission package.

Tom

[apdude]

Hello All...

I am in the process of building a blimp with some special nav/sensor/onboard computing/photo stuff on it. It's for outside and will be between 18-22 ft. I have heard all the size issues so am working through those.

I am debating on propulsion systems. These are my ideas I am kicking around.

1) Traditional Props mounted on each side.

2) Ducted Fans like used in the "Jet" planes.

3) Ducted Props. These I cant find anywhere out there.

Any clues for speed, power, efficiency, battery life, coolness factor, etc?

Thanks
Tony


Started on expanded hyperblimp blimp design based on ultra streamlined shape. See hyperblimp design at hyperblimp.com very innovative. Looking to use for aerial photography and I want to go fast. My own thoughts are a slight variation on control and size. Dan’s design pivots the motor on the very back for steering and he's using a length of 16 with a diameter of two. My plans are for traditional fin control with a twist a Y tail, only three fins two on the bottom for elevator and the top for rudder. This should reduce drag and weight leading to more speed. Staying weight permitting with a diameter of two and a length of 30' or so. Trying to really stretch this thing for speed length really does not matter and eventually you'll get the volume you need this makes speed. Staying with one motor for efficiency and weight. Have big axi motor and kokam lipos to throw in, with enough speed the tail fins should be all that is needed for control. Hoping for 30 or 40mph!! With all this fairly new technology… brushless motors, lipos, and a very clean streamlined shape I don’t think this kind of speed is unattainable. By the way I’m a native Oregonian lived on Hayden Island for years!!! Wish I still do.