Ice Fun

What is the maximum weight for a camera that's put on a 6.5 pound .46 glow plane assuming it is directly over the CG? I know you guys use the light aiptek cameras but I have something a lot heavier (17 ounces) and I was wondering how big of an engine is required for such a camera.


kevin

antslake

My Feedback: (1)

You should be more concered about wing loading, then power. With a big enough wing(or more correctly, a wing with more lift), you could carry quite a bit with a .46 engine.
That's why people use the slow stick, cause the wing has so much lift. The motor is secondary.

SON OF PALEFACE

My Feedback: (1)

I agree , wot is the wing area and wot section is it ...........U shood B able to go to about 30oz per sq ft , and also U need a stable design ie trainer or glider ect

Bob Laine

My Feedback: (91)

How much does a 25 year old man weigh?

Andrew Ditchfield

Increased weight will mean that you have a higher stall speed, which means you need more speed to take off and you have to keep up a higher speed on landing to keep from stalling. You have to decide what take off and landing speed you are comfortable with. For a video/camera application I would think you want to keep this low so you can fly out of many different areas without needing a long runway.

For a given airfoil design, you can get the stall speed from the wing loading. The wing loading is the models gross weight (including fuel) divided by the wing area. Most .40 sized planes are in the 20 to 27 oz/sq ft range. If you double your planes wing loading your stall speed will go up about 50-60% for a wing with a lift coefficient of 1.0.

If you plan to add significant percent of weight to the model a good solution would be to try to lighten the plane in other ways or extend the wing to maintain the wing loading value. You can lighten the plane by using the skylite wheels and eliminating any lead weight you had to add by moving around radio components (or camera equipment) to balance the model. You can also use a half tank of fuel and just fly for half the time.

It also helps to start with a "floater" plane that has light wing loading. I would recommend a .40-.60 sized Piper Cub.

If you want more technical information I recommend "Basics of R/C Model Aircraft Design" by Andy Lennon.

Good luck.

Andrew

JettPilot

My Feedback: (6)

Ice Fun,

To answer your question, any .46 trainer ARF out there can be flown with a 17 ounce camera no problem They even fly with 2 pounds if you have the skill to do it It gets harder as weight goes up, but they can fly a suprising amount of weight.

At 17 ounces, its a bit harder to fly, longer takeoffs, and you need to be careful not to climb to steeply and stall, but 17 ounces is not bad at all. Give it a try !

JettPilot

SON OF PALEFACE

My Feedback: (1)

If you are an experienced flyer , you will be able to handle this , the EASY WAY to do a/p is with a slow stick , or Multiplex easystar , easyglider with a smaller camera , and with flaps/spoilers if you want 2 get in and out of tight areas...a slow flying plane will take clearer/sharper shots..........there are LOTS of HARDER ways to do a/p [X(]

Ice Fun

Well, I guess if I were to do it I must lower the flaps all the way down, add wing extensions, and apply more throttle for the extra weight.

JettPilot

My Feedback: (6)

Flaps ususally make a model airplane more difficult to fly [:'(] Not to mention, they reduce the performance, and with extra weight you need all the performance you can get. What im saying is dont mess with flaps, or get to wrapped trying to do a bunch of schit, just strap the camera on and go for it

If you need to change something, it will become very apearant durring the test flight. But 17 ounces on a .40 sized trainer will not be a problem...

JettPilot

daubut

My .46 trainer has a wing area of 650 sq/in or 4.51389 sq/ft. The weight of the plane with a full tank of gas and all my current video equipment installed is 7.6lbs. My CG has not moved lateral, but my longitudinal has. It is obviously transferred it towards the side of the plane where the camera is mounted. I am going to try to add some wing tip weight to the opposite side to try to balance it back out. Still worried about the drag and vibration that might be caused by the large frontal area of the camera when in an upright position. When the camera tilts down the cg moves a little maybe ¾” aft. The plane is still a little nose heavy with an empty tank of gas, but I would rather it be nose heavy than tail heavy any day. I am going to weigh the setup again after I receive the downlink hardware next week. Adding another battery pack for AV TX is going to require me to move components around for sure to try to rebalance the plane and keep the CG acceptable. Will be doing some test flights tomorrow. I will post some pics of the finalized setup and let you guys know how she flies. Till then have a great weekend and let’s fly!

daubut

Well I added almost a 1.4lbs to my .46 trainer 63" WS and she hopped right off the runway no problem. 5-10mph winds. Check out the first test results here:

http://www.rcuniverse.com/forum/m_5048743/tm.htm

I figure after the wireless downlink is installed it's going to get even harder to fly. Slow turns now and a little tail sliding but she flys pretty docile. Good luck with your tests.

JettPilot

My Feedback: (6)

Cool deal ! I was confident that your trainer would lift your stuff no problem The video TX is very small and light, you wont even notice its there

The plane will also fly in a wide area of CG [X(] It will become more difficult, but I have flown some of my models at 50 % CG back on the wing, in other words very tail heavy.... It would spin if I slowed it down to much, and it was pitch unstable, if it went up, it would try to go up more, same with down, but it flew I just had to be more careful flying it that day. I did fix the CG, its a bit more risky flying like that and I would not leave a plane setup with an aft CG permanently, but it allowed me to do what I wanted to do that day.

JettPilot