Lee.org

In looking for more batteries, I found the specs for the Sanyo KR1700AU batteries in my Zagi. Sanyo says that at 8C (13.6 amps) the battery lasts about 5.2 minutes. That was exactly my experience. So whoever says they get 7 minutes WOT (Wide Open Throttle) on these batteries is…. well, I don’t think they are.

Also, Sanyo recommends a “fast charge” current of 2600 mA on the KR1700AU! NOT the 1000 mA that the Zagi manual and Cliff Whitney recommends! That means you can peak charge these batteries much faster than you might think!

I gleaned this estimate from my journal entries. It’s mainly to try and figure out how many battery cycles I’ve gone through (I want to get a third battery pack and charge two of them at the same time. To do this, the batteries should have about the same amount of wear on them.)

total flights
6-7 8
6-9 4
6-10 3
6-12 1
6-14 2
7-12 2
7-14 4
7-16 2
7-17 5
7-20 5
7-21 2

———–

approx 38 flights so far. 19 on each pack.

All this time, I’ve been throwing the Zagi too hard! I’ve been giving it this solid baseball arm toss to make sure it launches correctly. Well, it turns out that it’ll get into the air just fine with a little heave. I’ll work some more on finding out just how light a toss I can give it. I’ll also work on my side-arm throw :-).

Upside Down

I learned how to fly inverted today :-)

I had been at it a while but wasn’t getting anywhere. So I went down to Great Meadows today and Julian was there with 2 new flying friends. I mentioned my troubles to Julian. He took my transmitter and asked me to throw the plane in the air. It was nice being a “passenger” on a flight. I don’t get to do that a lot :-). He gets up to altitude and then FLOOP, he starts cruising around inverted. He’s such a show-off ;-). He showed me the controls and I realized that my trouble had been that I was flipping and then trying to level off when the plane was moving too slowly. I’d give it full down-elevon and end up essentially trying to hover. Of course that wouldn’t work because it’s a 25 oz. plane with only 9.5 oz. of thrust… so I’d descend fairly quickly with the nose futilely struggling to reach the sky. Julian demonstrated to me that I needed a little more airspeed before I could fly inverted.

Correct!	Incorrect – not enough speed	Incorrect – Can’t pull out fast enough

Flying inverted isn’t that hard now. The controls are a bit more touchy. I think the plane is constantly trying to right itself (a good instinct in general!). As Cliff Whitney’s email .sig says, “When flying inverted, down is up and up is expensive.” I haven’t figured out the stall characteristics but I think they’re probably much less forgiving.

Now I’m zooping all over the place right-side-up, up-side-down, in-side-ou.. well, I’m not that good yet.

I also worked on flying very low and slow. Some day I’d like to try jumping over the plane in flight.

Zing Wing Fun with the Zagi

Before Julian, Mike and his son left, we had a VERY fun game of catch. First we were playing with the Zing Wings. Mike really liked them and vowed to buy some. I got mine from Atlanta Hobby. Then we tried using the Zagi as a launching platform for them. We’d wedge a Zing Wing in place on the plane, send it up a hundred feet or so and then shake it loose. I got to fly the plane, which meant that, as Julian pointed out to me -3- times, “When the Zing Wing comes loose, you watch the Zagi, not the Zing Wing!” Some of the Zing Wings wouldn’t come loose. Heck, the Zagi looked like a bucking bronco, pulling left, right, left, right, up, and down. But the Zing Wing would hold on tight. Of course, as soon as I’d set it down, the wing would pop right off. Finally the best placement method was found at the end… Julian insisted it wouldn’t work but I tried anyway, and it did! I held a folded wing along the front edge of the plane by the winglet with one hand and launched it with the other hand. Julian gave it full throttle and off it went, Zing Wing in tow. A little hammerhead stall and the Zing Wing was free.

John E, my neighbor had a good story to tell me about a Firebird XL that they got for their son on his birthday. To make the nice story very short: After finally getting the thing in the air, he did some gentle turns and then the thing just locked up… full throttle, straight flight. And off it went! John told me, “Of course it was funny later. But while it was flying away, all I was thinking was, ‘There goes $150 dollars.'” The plane flew off into the wild and was never heard from again. They found the right spirit and it gives them a good laugh now.I took John out to Great Meadows. We had a lovely time killing the afternoon.

2″ PVC

I got a 2″ PVC pipe for my forced-air battery cooler. That’s more like it.

Rain rain, go away
Come again another day
Wittle Wee (the one who wivs here) wants to play!

Here’s the Allamuchy ball field that I sometimes fly in.

I got a little carried away with Mapquest…. Here is the club field I fly at, RAMAC. The area sure is perty from the sky, ain’t it? And these shots are in winter! The field itself isn’t much to look at. The dots near the bottom of the triangle in the first photo are cars in the parking lot.

Here’s the Pocono field… sorry the images aren’t as good… blame Mapquest!

And for posterity, more shots of the WCCC field.

I just measured the static thrust of the Zagi by balancing it on my postal scale, nose down and cranking it up. It’s unbelievable. My skills have improved wildly in the last couple months, I’m able to control the plane much better than I could when I first set it up and the amount of thrust has…. get this…. decreased! I honestly, honestly thought that the motor had broken in and I was getting more thrust, aiding me in my quest for domination of the skies. But nope! A month or so ago, I was getting 12 oz. of thrust out of the motor. The Zagi website makes mention of getting 16 oz. of thrust… I’m getting only 9.5 oz of thrust. And I couldn’t be happier. That’s so strange!

“You got mud on your face you big disgrace
Somebody better put you back into your place”

I went to Great Meadows and was quite surprised to find the parking lot almost full! Thursday is a big night at Great Meadows! I was planning on staying just a little while but ended up staying from 6 to 9pm! I met a nice father & son…… I’m so bad with names… Alex and ??? I think, from Long Valley.

As night twilight was approaching, I flew the Zagi dramatically into the sunset… and lost track of it’s silhouette. She took a good dive into the dirt on the far side of the canal. Shift forward 30 minutes, when we’re all packing up. I went over to the father & son and gloated about how they were cleaning oil and gas off their planes while I didn’t have to. Yea, I just had to clean the mud off it. At that moment, I felt like a rough-and-tumble scallywag.

I bought a computer fan at Staples to cool off my batteries. I also got a 3″ PVC pipe to set the battery in while cooling but… jeez the 8″ piece of pipe is the heaviest object in my case. I’ll go look for a smaller, thinner walled pipe. I suppose I shouldn’t have gotten a pipe rated for 270 psi, eh? But that’s all they had in 3″ pipe… Eh. I’ll figure out something.

Oh and the fan has cool purple LEDs on it. When my dad came home from dinner and saw the contraption charging in the garage, he called me Doctor Frankenstein. hehe.

Yesterday I went out with Doyle and Julia to the little Allamuchy baseball field. I got to see Zagi Flap for the first time. It freaked me out! I got it up to about 250 feet and dove at about 80 degrees at full throttle. Only 1/2 way down it started flapping like a crazed swallow, like 5 times per second! I thought the battery pack was going to pop right out in mid-air! Well, it didn’t but I was so freaked that when I brought it in for a landing to see if it was ok, I scraped it against a fence, tearing the starboard elevon off for the third time. I gotta get coroplast elevons.

Soaring with Eagles

Yesterday morning after class I was flying at WCCC. I saw some eagles (hawks?) catching a thermal at 300 feet so I went up to meet them :-) I found their thermal at 200 and rode it to about 350 with them. Very cool! I got pretty close to them… riding the thermal maybe 50 feet vertical below them. I thought they’d be completely freaked out by the plane but they didn’t give up their thermal for at least a minute. I’d like to think they were done with the thermal but yea, I probably scared them off.

Dynamic Soaring

Today I went out to the Allamuchy field… it was a really windy day. Though the field is small and flat (it’s just 3 little league baseball fields) I tried dynamic soaring. What a hoot! All I had to do was loop carefully and I’d get some speed fer free!

I’d come in 3′ off the ground, shoot up 20′, fly inverted for 40′ and come back down near the ground. Since the wind is moving faster at altitude, I come out of the maneuver faster than when I go in! I’ve still got to work a lot at my vertical turns. This time around, I could rarely do more than one loop before pulling out of it to stabilize myself. And I was using a lot of throttle to keep me going. If I was -really- good, I’d be able to do this with no throttle at all!