Flyiing an Atmopod

[Jim_Marconnet]

Got my Atmopod assembled, radioed, and maidened Monday. Bashed it into the grass several times, and it seems just fine. Tough, resilient little foam and carbon flat critter!

Orientation is my big concern just now. Hope to get past that quickly.

Want to make some volts/amps/RPM measurements with several different LiPos I have on hand and then start doing the suggested floor exercises in earnest.

Hope to hear from other Atmopod and other VTOL pilots here.

In case you are not familiar with the Atmopod, see the E-zone review: http://www.rcgroups.com/links/index.php?id=4840

This looks like a real hoot to fly once I get a little air time with it.

Jim

[v22chap]

That looks like it would be a hoot to mess with ..
Let us know how it goes
Larry

[Tuner]

I like this it give me many Ideas Hmmm.

Love to hear how it flies I might pick one up.

[derk]

i tried to build my own but the first run of the throttle and the foam exploded (i think the prop might not have been balanced) it was funny to everyone else tho.

so how much does yours weigh?

Derrik

[Jim_Marconnet]

i tried to build my own but the first run of the throttle and the foam exploded (i think the prop might not have been balanced) it was funny to everyone else tho.

so how much does yours weigh?

Derrik
Sorry to hear of your explosion. Wish there was a video of it! :)

The Atmopod is Depron sheet with carbon flats glued along all the edges. Makes it very light and strong.

My weight is 7.9 oz without battery. 10.1 oz with an E-tec 2S 1000 mAh pack and 9.4 with a Kokam 2S 700 mAh pack. That's a little heavier than the instructions say it ought to be.

Jim

[Jim_Marconnet]

i tried to build my own but the first run of the throttle and the foam exploded (i think the prop might not have been balanced) it was funny to everyone else tho.

so how much does yours weigh?

Derrik
Perhaps this video will do as a substitute for yours that wasn't videoed.

http://www.heli-chair.com/videos_public/full_scale_heli_videos/ground_resonance/

[Terry S]

WOW....what caused that ?

Terry

[Jim_Marconnet]

I just wanted to share a photo and several graphs I got from some Atmopod tethered hover testing in my home office using my Hyperion E-Meter and the PC interface cable/software.

I tied a string to my ceiling fan. Ran a piece of string trimmer line thru a hole drilled in the Atmopod, and used a fishing swivel to connect them. In this particular setup, the instrumentation shunt cable prevents rotation. But for normal tethered flight, free rotation lets me practice roll-control at different throttle settings up to full hover.

Connected my computer interface cable to the E-meter, and the shunt between the battery and the ESC. Taped the E-meter and the serial cable to the string with scotch tape to keep it all out of the prop.

I used a Kokam 2S 700 mAh and an E-tec 2S 1000 mAh pack for this testing, swapping them back and forth several times to see how they compared. So my data is all mixed up, pack-wise. But I saw no huge difference between the two packs in this testing. So I plan to fly with either of them.

First moved each control surface separately to see if any servos were sticky, etc. Nope. Saw about 1/2 amp per servo.

Then moved all 3 servos to/from full travel as fast as I could at once and saw about 1.5 amps max. It figures. 3 servos, 1.5 amps total max. So the ESC is not current-limiting.

Then tried slow motor, with counter-roll control applied.

Then powered up to hover. Saw about 12 amps constant current.

Then tried a "jump". Zero to full power, then back off quickly when it's a foot or so in the air. Saw peaks of 16, 17, 18 amps, depending on the pack and which jump. Jumps are a little exciting indoors, even tethered. They call it an "electric rocket!"

Touched the motor several times, but never noticed the outside getting warm. Forgot to touch the packs for temperature. But they were not hot when I swapped them back and forth. So no problem noticed there in this limited testing.

Given this data showed nothing anomolus, guess I'm ready for some serious indoor hover testing.

I added the Green dot and the Yellow stripe to simulate a vertical stabilizer to make orientation easier for me.

[Jim_Marconnet]

Just wanted to mention a few things I've encountered in my Atmopod tethered indoor flight experiments.

Hope others can share their tethered hover experiences and what they learned from them.

Yes, a lot of this is probably old-hat to you 3-Ders. But most of my flying time is outdoors on a Slow Stick!

First lesson: Don't let the tether get into the prop, or it will tend to get chopped up. Chop off any excess string, don't let it hang down. Don't make the tether near the plane anything that could hurt the plane if it hits it or gets chopped by the prop. So far long rubber bands seem a lot better than string.

Don't hover so high that the tether loops down into the prop. This effectively limits tethered vertical hovering to about a foot high in my case, due to where the prop is with respect to the nose. Perhaps a formed "Chicken-wire" or "onion bag" guard could be placed over the nose section to prevent the thether from getting into the prop.

Throttle. Of course, more throttle gives more RPM and thrust, up to the point that lift-off occurs. Tethered, and in a limited flying space, I don't really want to get too far off the ground too early in the process. So I'm near-hovering mostly rather than actually being at zero-G. That means the tether always puts some tension of the plane and affects its position side to side and up and down. But it allows nearly free-spin about the motor axis due to the fishing spinner.

I have a long rubber band connection at the nose now to minimize shock at "landing". No point in risking ripping the nose off if you back off the throttle quickly or if the ESC LVC shuts it down.

Roll control. Due to motor/prop torque, the plane tends to spin clockwise looking down onto the nose. So I need full right-aileron before takeoff and during hovering to counteract this. I may even need to increase the elevons throw to get as much right-stick roll as I need to be able to roll right in flight. Obviously less roll-input will be needed in conventional flight modes. I suppose throttle-roll mixing could be experimented with. For now, I'm doing it all with the Tx sticks and my primitive "cranial" mixer.

Elevator. The Atmopod "wing" is white. So moving the right stick up and down with some power applied (and the Atmopod suspended a little off the floor) swings it back and forth (up and down) along the axis of the body (black surface). Supposedly the elevator and rudder actions are reversed when at or very near the ground. So learning this reversal and when it transitions back to normal may be interesting.

Rudder. Likewise, moving the rudder side to side swings the plane right/left along the wing, the white surface. Well Duh!

Because its tethered, slight movements side to side become swings rather than horizontal movements in the free air.

So far I'm learning that with careful visual attention and lots of sticks inputs, I can control the plane in all the various directions and rolls. And keeping the plane pretty much vertical for it to hover in place rather than to fly away.

Clearly I'll need some daily practice for a while.