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When I bought the new 1100 mah battery, I told myself that I should return the 100 watt Radio Shack soldering gun (64-2193) I bought to assemble packs with. But I didn’t :-).

I had never used a gun before. All these years I had this impression that irons were the way to go… because. I’ve got the Radio Shack 15/30 watt dual heat iron and have been happy with it for a long time. But after trying the gun, I’ve got to say that I am -very- impressed with it’s power and ease of use. IE: Plug gun in. Pull trigger for 10 seconds. Start tinning tip of gun. [yes, 10 seconds, not 10 minutes] Release trigger while positioning pieces to be soldered. Pull trigger and wait 3 seconds. [yea, it’s a slight bother that it’s not always at the ready like an iron, but the tip needs less tinning] Touch tip to Deans Ultra connector, wire and solder for 3 seconds to solder together. [The 30 watt iron would take 10-20 seconds of heating time]. It’s also nice that the gun is safely cool again in 5 minutes.

I like the gun.

So now that I’ve spent the $12.99 on the gun and I’ve browsed too many battery websites, I might just build my own packs after all. More details as they develop.

As I was going to the field, I heard a severe weather advisory for eastern PA…. 30 miles to the west of me. Did that stop me? Nope! Of course, I flew like crap in the gusty 25 mph winds…. but I flew! I also busted the elevon again when I hit an outfield foul-line pole. Nothing a little Krazy Glue can’t fix. I can now get into inverted flight via a 1/2 roll… in 25 mph multi-directional gusts, no less. Tré cool.

Optimally, I’d want a battery 1500mAh battery, under 10 mOhm, under 30g. 20mOhm is right out. Here’s stats from Sanyo’s website

comparison according to Sanyo charts:
CP-1300SCR – drained after 8C for 6.9 minutes. that’s 10.4 amps for 6.9 min (.115 hrs). 10.4 * .115 = 1.196 amp/hrs
KR-1700AU – drained 8C for 5.2 minutes. that’s 13.6 amps for 5.2 min (.087 hrs). 13.6 * .087 = 1.1832 amp/hrs
Conclusion: you get an insignificant 1% more amp/hrs out of the CP-1300SCR during high drain applications (like flying wide open throttle). At lower drain, like when cruising around, the KR-1700AU does better.

The HR-4/5AUP looks like the best candidate. Andrew Mileski on the Zagi group says it’s his favorite and that’s good for something. It pains me slightly to spend $70 in batteries + $20 pack making supplies… Hmm. But thinking about it, I’ll then have 2 complete kick-ass packs for $45 apiece. So the cycle would be: fly the 2 new packs for 25 min. Fly the 1100 Ni-MH for 10 min while letting the pair cool. Start charging the new pair at 1.5C. Fly the 1700 Ni-Cad pack for 15 min. Sit out for 30 min. Then start charging the 1100 Ni-MH and start flying the pair for 25 min.

I suppose the best and most simple configuration would be for me to have 2 pairs of batteries and a charger with a charge delay. Then it would be:
fly pair #1 for 25 min
plug pair #1 in (with a 5 minute cooling delay on the charger) at 1.5C and fly pair #2 for 25 min
sit out for 20 min
plug pair #2 in at 1.5C and fly pair #2 for 25 min

But now I’m just fantasizing…

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!

Hydrogen power appears just about inevitable. Here’s a good pro-hydrogen paper I found mentioned on the EV mailing list. The original is on this site.

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.

What Prevents People from Listening?

Our development hired people to power-wash the exterior of all the homes. Yesterday, the association stuck a note in our door saying that we had to remove all the furniture from our deck and take off all the window screens.

So why did I have to argue with my family about moving the furniture? It went something like this:

“Dad, help me move this planter inside”
“No, we don’t have to move that. It’s too heavy. They’ll just push it around when they get here.”
“I don’t think so. The letter said to move everything. What about the table and chairs there?
“They’ll move that too.”
“But Dad, look over there next door. See how they took all the furniture off the deck and it’s sitting on the grass? We’re going to have to have to do that too. The letter told us to move everything.”
“No we won’t. Don’t worry. We weren’t even here when they did it last year.”
I start moving the planter inside. “Give me a hand here.”
“No! They’ll do it.”
“Dad, go inside.”

I moved most of the planters by myself.

Ten minutes later, I was out on the other porch and I was a fool. I tried to have a conversation about what to do with the gas grill. I said, “Now I’m just thinking here… maybe we could unhook the gas and they could roll it around the porch when they’re cleaning it. I’m not going to try to roll it inside.”
After reading the letter, looking at all the neighbors’ homes, and watching me move stuff for a few minutes, he replies, “Just leave it.”
“Dad, get out of here.”

I went downstairs and started moving items out from under the upstairs porch. While I was doing this, a workman standing at the next house saw that the planters had been moved inside but the furniture was still on the porch. He said in his broken English and waving his hands to help get the point across, “We going to lunch now. You move that, up there [pointing to the furniture].”
I came back with a nice smile, and pointing to help get the point across as well, “After lunch, we’ll move that off the porch together?” He nodded and smiled. A few minutes later, they went off to lunch.

While I was still moving stuff, my next-door neighbor came out to look at his 3/4 power-washed house. I’ve known him for a few weeks and he’s pretty nice. But today he was a grumpy old man. He gripes at how they missed some spots and how the workmen are no good. I point out that they only stopped for lunch. He gripes at how they dirtied up the windows with the water (yes, he was complaining about water on the outside of his windows). I tell him that they’re here to do power-washing, not windows. He still gripes. I look closer and point out how they have power-washed one of the windows and it looks really good; ,”hopefully they’ll do the other windows when they come back from lunch.” He gripes at that.

He asks me if they’re going to paint the windowsills. I say, “I don’t remember, I think it’s in that thing they slipped in our door. I know they’re going to seal the deck.” He says what a pain it was to get the screens off and asks if they’re going to paint the sills. I say, “I don’t know. It’s written in the contract what they’re going to do.” My dad pokes his head out and I ask him to check the paper and see if they’re going to paint the sills. He goes and says that yes, they will. I point out the one screen he couldn’t get off, saying that they won’t be able to do as good a job painting the sills with that screen on. That they might get brown paint on the white screen and that wouldn’t look good at all. He says that he doesn’t care. I smile and nod that neighborly smile and nod.

I then took another 20 minutes walking around the whole house, removing screens and moving planters and such away from the house.

An hour later, I’m downstairs on my computer and I hear a higher-than-normal-pitched cry from my mother, “Lee! Can you come up here?” I get up there and the two of them are out on the front steps. She starts in on me in a nasty accusatory fast-paced yell, “You were supposed to move all this stuff! Why didn’t you move all this! Now we’ve got to move it before they come. What were you thinking?”
I had had it. First I get yelled at to not move stuff, now I’m getting yelled at because I should move stuff. Even though… get this… I -did- move everything. So I turned it on and redoubled her nasty tone and pace, “I did move everything. LOOK! Do you see how everything is away from the wall they’re going to power-wash? I moved all that! Look. They are going to power-wash this wall [touching the shingled wall] and they are not going to wash this wall [touching the stone wall across from it with some planters lined up against it]. I’m done.” She kept silent. I went back inside.

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