I took her out today. It's really a blast. My favorite from today was taking off at 3/4 throttle, taking a moment to verify stability and then giving her full throttle. She pulled out at an 80 degree angle until I told her to stop... about 400 feet. I'd have her go higher but I can't see her any further away!
I lost my 10 cell NiMH :-( I was practicing hammerheads (and getting moderately good, I might add!) when the battery fell out. I foolishly watched the big yellow plane fall all the way to the ground instead of following the tiny little battery. I looked for about 30 minutes but no luck. Well, I guess I'll be getting a new matched set of NiMHs.
Wow, Cheapbatterypacks.com can build me a 10 cell generic 1050 mah pack with Dean connectors for $20/pack. That's like 1/2 the price of my local hobby shop, with -exactly- what I'm looking for instead of whatever happens to be in stock.
I'll wait to put together the Trick 1000 and see how it flies with the LiPoly pack. Then I'll probably get a double set of batteries.
I wonder how I'm going to get all this stuff on the plane!
|
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(Actually, that's 2 planes, a bike and some extra neon to round the order up to 100 feet.)
(eeearly morning edition)
Hmm. I
need
a lot of electroluminescent wire for the plane! I'm starting the measurements
and it looks like it's going to take 11" per loop/feather. I'm planning on 48
loops on the bottom of the plane, plus some outlining.... that's at least 44
feet of wire just for the bottom! Hmm. What does 44 feet of wire weigh???
I have a sample coolneon kit with about 77 inches of the stuff. It weighs 1 oz +- 5%. So that's 7 oz of wire for the underside... another 4 for the topside, 1.4 oz for a 9v battery. Hmmm 13 oz of payload on a 28 oz plane. Maybe not. I'll work it out.
PPG gave me the really good idea to look for Egyptian figurines as a model. (yes, I saw her. I think our friendship will survive) I found Ma'at, the Egyptian goddess and embodiment of truth. You'll likely be seeing an aerial Ma'at over the skies of Black Rock City in a month!
That's Ma'at on the left and Isis on the right in the picture.
I took the Zagi out to do some sample flying
Zagi 400, 26 oz (including motor & battery but not payload) 292 sq in wing surface, Mega 16/15/4 motor, 6x4 prop, Zagi 8 cell 1700 Mah battery, + 10.5 oz of my grampa's old tools
It flies just great... It flies a little erratic (probably because the weight is on the top of the wing, pushing the center of gravity up) and it's a little harder to turn (likely inertia) but the big thing I was worried about was that it would sink like a rock and that isn't an issue, and I needed to lay hard on the throttle (mostly due to me flying in 20mph slightly gusty winds just before a storm (I want to make this project happen NOW!)), and I had to jump a fence to fetch the plane once (When I took off, I lost a 1 oz weight that I had placed mid-wing, that started a leftward spiral that, in order to save from a really hard crash, I ended up hitting a fence and the Zagi tumbled over the fence... hence the climbing. I'm confident that I can put a 13 oz. lighting payload on a plane
Static thrust motor output: NiMH1: 16 oz, Nicad1: 16oz, LiPoly: 23 oz!
That's a 36oz plane with 16-23 oz of thrust... very respectable for an electric. I had previously gotten used to getting 9oz of static thrust out of brushed speed 400s. Represented as fractions:
| Plane | thrust (oz) | flying weight (oz) | thrust/weight ratio |
| Old Zagi (brushed) | 9 | 26 | .35 |
| New Zagi (brushless) | 23 | 26 | .88 |
| New Zagi with payload | 23 | 36 | .64 (way better than the old Zagi) |
| New Zagi with payload (old batts) | 16 | 36 | .44 |
| Projeti | 23 | 20 | 1.15 (>1, vertical performance) |
After crunching the numbers, I am resolved: just do it.
Phew. I'm getting used to it. The darn thing scares me it's so fast! I took the Projeti and both batteries (I didn't forget them this time) out to the Allamuchy park. I'm surprised to say that, even though it's only got a 32 inch wingspan to the Zagi's 36", that field is only barely large enough. I would zip from one end of the 3 little league fields to the other in no time flat. It was also kind of funny... I'm used to launching while standing at my car and then walking over to a good spot while gaining elevation. There was no need for that any more since she gains altitude so quickly! In just a few seconds, she will fly nearly out of site. I had to try banking left, right, up and down just to tell her attitude!
But I like that I was able to pop it in the car, drive over, pop the battery in and fly. Electric is nice.
I'm a bit concerned that I'm burning out NiMH1. When I took it out of the plane on 7-11-04, it was like 300 degrees hot. The EPS had slightly wilted underneath where it had touched inside the fuselage. On 7-23, I only got about 5 minutes out of it while I got about 20 minutes (Yes, 20 minutes!) out of LiPoly1
I took the brushless off the Projeti and put it on the Zagi. It's too fast! I can cause dreaded Zagi Flap in level flight! Of course, this also means that I can run it at 1/2 throttle with lots of speed for a very long time. I frown a little at the Zagi for not handling high speeds well, but hey, it's good at other things like crashing. Which leads me to my next topic...
I was showing off a little for some kids that moved in to a house on Alphano Road, the middle house. Actually, when I crashed, I wasn't hot dogging or anything, I was just making a sweeping turn near a tall kite-catching tree. And who could blame the tree for not knowing the difference between a kite and a flying wing? I'm just glad it didn't get tangled up in the branches but fell to earth. I think it might be time to put those coroplast elevons on. The balsa elevons are more CA than wood!
The second surprise was with the batteries. I attached the 8 cell Zagi battery and flew the Zagi. I was surprised to find no difference at all in performance. But shouldn't an 8 cell pack turn the motor slower than a 10 cell pack?? I didn't listen too closely but I didn't notice any difference in prop noise either. Hm! The Zagi battery doesn't physically fit inside the Projeti so that test isn't going to happen.
-----------------
Battery use estimates:
| NiMH1 | LiPoly1 | NiCad1 | |
|
previous |
35? | 0 | 26 |
| 7-11 | 2 | 0 | 0 |
| 7-23 | 2 | 1 | 1 |
| total | 39 | 1 | 27 |
First flight was with the help of a new friend, Dan, who lives just down the street from me. I guess I've been having some bad days and it's surfaced.... My car's battery is dead. It's a bit stressful that I can't drive where and when I want. So I went to the field in my dad's car. When I was getting ready to fly, I realized I had left the LiPoly at home. Bummer. Then I reached over to the transmitter and turned it off. But wait, shouldn't I have turned it ON?! Grrr! I left it on for 2 days: dead transmitter battery! Dan was kind enough to give me a hand seating my NiMH pack and he lent me his transmitter, very nice.
If flies fast and high! It likes to go up! It's got --almost-- full vertical performance... With a little speed, I can run straight up for like 75 feet, which is PLENTY. It'll go up at a 45 degree angle until it's out of sight. It goes about 90-100 MPH in level flight!
The entire first flight, I flew it as gently as I could, trying to get used to it and reminding myself that this wasn't a crashproof plane! things got a little hairy with the sun getting in my eyes.
The second flight didn't go so good. I launched it, it flew about 30 feet and then.... well... large pieces started flying off it! I cut the power and it fell to the ground. It seems that the spinner had gotten loose and the prop vibration tore at the plane. The motor tore out of it's mount, a not-so-important piece of the tail was chopped off by the prop and a crack in the EPS formed almost all the way across the fuselage about 4 inches back from the nose. :-(
Break out the crazy glue and tape! After a little while, I was ready to go again but Dan had to go (taking his transmitter with him. Jason showed up as Dan was leaving. He wanted to see it fly. I remembered that I had a home-made quick-charger plug for the battery and plugged it in. Surprisingly, I got a near-full peak charge after only 10 minutes on 1.5 Amps (the transmitter batteries are 600Mah AA batteries). I stuck the NiMH's on and was ready to go in 20 minutes with a 75% charge. I prepped her for flight and let her fly! She went along straight as an arrow out of my hand, I pulled back on the stick and she dove into the ground like a lawn dart! AACK!
I had forgotten that Dan fiddled with my receiver, reversing a wire! I should have done a better flight test! I recall a quote from Cliff Whitney, "When flying inverted, down is up and up is expensive". The motor mount had held up but the foam holding the motor mount, about 1 inch into the plane gave way, tearing about as large a chunk as possible from the top rear of the plane. When the tail came loose, it chopped through part of rear of the wing, leaving a gash.
Well, after about 30 minutes of gluing and taping, she was ready to go back in the air. I had tried to collect all of the yellow foam from the crash site but I was missing a couple bits. The gash in the wing remains even still. I got her up and she was great. Smooth and fast flying. She rolls like... she rolls quick. I was getting ready to try inverted flight but as it unsteadily came out of the 1/2 flip and nosed toward the ground a bit more than expected, I recalled that I needed more experience with the plane before doing to much with it. Suffice to say, she flies very well.
I don't think it's appropriate for the task I was going to put it to at Burning Man. She's too small, too fast, too unstable. I need something big that can cruise around showing itself off. The Zagi is just about big enough but not stable enough. I've got my work cut out for me here!
I'd have taken pictures of all this but my aunt borrowed my camera. I'll have it back soon.
Here is the Kavan web site (the maker of Projeti)
With nothing better to do on the plane, I charged, discharged and charged the LiPoly battery to see how much capacity it really had. I got some strange results:
The battery is a Thunderpower 2100, with a manufacturing stamp on the label of 6-4-04
So, what's up with the Triton only drawing down to 10.5 volts? And why did it only pull about 1.7 AH instead of 2.1 AH? I called Sal at NESail and he had a lot to say.
First, he warned me very sternly (!) that I shouldn't ever ever ever discharge a LiPoly on a charger. There's no need to and it could damage the battery by drawing the battery down too much. Discharging in a charger is bad because, if a LiPoly is brought down too flat, it's capacity will be permanently significantly diminished; a charger discharges the battery too slowly to hit the obvious 3 volt/cell wall. If you are flying, the high drain on the pack lets the drain work correctly. In addition, a good speed control will tell you when it's time to come in for a charge. You shouldn't drain the battery more than 75% or they'll go bad on you. That's 1.575 AH on a 2.1 AH battery.
It sounds like the Triton company is aware of this 75% rule. That's why they the charger only draws down to 10.5v on a 3 cell 11.1 v pack. The Triton charger seems to have a user interface problem. On the discharge cycle, the options it gives are "3v", "6v", and "9v". The obvious implication is that it will draw the cell down to the specified amount but it doesn't. It draws the pack down to what is considered "safe" flat... on the "9v" setting, it draws to 10.5v. Instead, it should give options like the following: "1 cell", "2 cell", "3 cell". Or "3.7v", "7.4v", "11.1v". Or "3.5v", "7v", "10.5v" because that's what it draws down to.
I've been talking about lighting the Projeti for Burning Man in my regular journal. I found a bunch of sources for wire. Well, I found the source I'm going to use: http://www.coolneon.com. This from the Coolneon gallery:
Now I have to lay out what I want on the plane. At $2/foot, I should lay it out with string before doing it with neon.
Sean at Castle Creations talked me through 2 diagnostics:
- Set the Soft Start option to “fast start”.
- Resolder the connections to the motor
Neither helped so he’s sending me another speed controller. It'll be here in a
couple days. I'll be in Vermont for the 4th so no flying 'til after I get back.
:-( And I don't want to bring the Zagi. The Zagi is tired. It needs
to rest.
It's together. :-) Last night, I reved it up to full power, pointing the nose up toward the ceiling. I could feel it pushing up against my hand. If I had let go, it would have shot straight through the ceiling. Well, not really... it would have hit the ceiling and then shattered into maybe five or ten pieces... but you get the idea; vertical performance :-)
And now the bad news: I was getting ready for my outing today and the prop wouldn't turn. When I gave it throttle, the prop would do this unhappy buzzing thing. The prop doesn't turn, it just vibrates! Waah! But today was the day! Wahhh!
I called NESail at 5pm and Carolyn said I'll get a call back by the end of their work day... which is at 6pm... in 5 minutes. :-( I don't think I'm going to get that call. :-(
Maybe I changed an important setting on the ESC when I tried to program it. It's a Phoenix 25 brushless ESC. It took me a while to figure out an important aspect of programming: go slow. If you try to program it too fast, it drops out of programming mode unexpectedly. I'll go try to program it AGAIN...
-------------------
NESail called me back at about 6:05 6 :-) The guy at NESail, Sal talked me though some diagnostics but couldn't help. He thought it was most likely a busted ESC, though such problems are rare. He motioned me toward Castle Creations. He says that if it's busted, I could exchange it though either NESail or Castle Creations. Of course I'm unhappy that I'm having trouble with it but NESail has been pretty sand-up-ish. I left a message at Castle Creations after hours. Hopefully they'll call me back shortly!
I'm about 3/4 finished putting it together. I've had two problems.... first, nesail.com sent me 14" servo extensions when I only needed 4" extensions. The extra 10" is a pain to stow away on such a small plane so I went to Kenvil Hobbies and bought 6" extensions. They fit great. Second thing: I couldn't figure out how to use the (very pretty) colleted prop adapter. In the process of trying to figure it out, I broke it. So I bought a new Master Airscrew prop adapter at Kenvil Hobbies. It works great except I needed an extra washer as a spacer; 15 minutes of swearing to myself in the nuts and bolts aisle and I found what I was looking for, a single 6mm washer.
Most of the decals are on. I wasn't going to put the decals on because I want to do it de'art for Burning Man, but I realized that they are an important structural element of the plane. They offer protection for the underbelly and most especially, the decal is 3/4 of the hinge for the elevons. Before I cut out the decals, I traced them on a sheet of clear plastic, so I might make another set of decals out of a material and appearance more of my choosing.
I ran the motor. Wooeee, it's windy! I had trouble holding it in my hand, it pushed so hard! I think it might offer more thrust than the weight of the plane! Woo hoo, hangin' on the prop is a possibility.... well, except that it's a pusher plane, but I'm sure you still share my enthusiasm.
While putting the Deans Ultra connectors on the LiPoly battery, I accidentally shorted it for about 2 seconds! Yipe! It didn't just spark, it fully arced, slightly pitting my Radio Shack holder thingie. Now, all I can think about is how HForo69 (an AIM flying buddy) told me how damaged LiPolys can burn out cars and burn down homes! Before I went to bed, I put the battery on the cement floor of the garage and put a big ceramic jar on top of it. (Thanks for the jar, Melis ;-)
I did some math on
http://brantuas.com/ezcalc/dma1.asp and ass-u-ming that my batteries can do
10C... this isn't for sure, the previous generation could do 6C and the new ones
are supposed to do 10C... but I don't even know for sure that I have a "new"
one. It says "6/4/04" on it which I suppose is the manufacture date, but that
could be the assembly date or....
So, assuming the battery can do 10C, this plane will totally rock:
The plane has a flying weight of about 20 oz :-)
The Projeti arrived today with all it's parts. That was fast :-)
Notables:
My second motor is on its way out. I lost another $1 prop to overheating. I'm a bit surprised at that because this second motor is a 7.2V motor... IE, it spins slower at WOT. I had figured that the first motor, a 6V motor was burning itself out extra quick because I was pushing it waaay too hard. And I was only pushing the 7.2V way to hard.
The 2 NiMH 1100 battery packs are having some trouble. I pretty much figured when I got them that I was drawing too much power from them. But I got a whole year of flying out of them, so I'm not unhappy. I tried strapping both to the plane and flying them in parallel. It worked reasonably well. The plane was heavy like a dog but it flew fine enough. I was a bit surprised when I landed the dual-pack arrangement and both batteries were very hot. Shouldn't I have been drawing 1/2 the normal amperage? Well, as I said, the packs are on their way out... But if they're on their way out (loosing full power after only about 5 minutes), shouldn't just 1 or 2 cells per pack be getting really hot? Eh. Whatever.
I ripped off a winglet Monday afternoon when I landed a little hard in some tall grass. So I tried flying winglet-free. YOW, bad idea! When I went into any kind of high-banked turn, the nose would turn toward the earth and I'd lose altitude like it was going out of style. I tried doing a roll without winglets and, YIPE! I had reasonably good form but midway through the roll, the plane started fluttering down to the ground like a piece of paper, flipping nose-over-tail and such. Just zooping about, it was hard to keep it flying straight. Any sudden shift on the controls or in the wind and the plane wouldn't know which way was forward. Bleh! Conclusion: The Zagi 400X cannot fly without winglets. I'm glad I did the experiment.
I just bought a Projeti electric flying wing and brushless motor set. It promises to go 3 times as fast as the Zagi, still with amazing acrobatics. I'm taking it to Burning Man in August. It's going to need a more artistic paint job than what comes out of the box. Too bad I don't have an artistic girlfriend.
Everything is coming from Northeast Sailplane Products http://www.nesail.com
I'll probably be lighting the plane with something from one of these companies:
http://www.glowire.com
http://www.rcneon.com
Here is a calculator for LEDs I might need
http://www.rc-cam.com/led_info.htm
What is in the mail to me from Vermont:
Sal at NESail tells me that at WOT, the motor/prop draws 26 amps, 24,000rpm, 237 watts
I'm planning on getting a hard-sided archery case to haul it to Burning Man. Maybe this one on the right, from http://www.unlimitedoutdoors.com/accessories.html
Or maybe I'll just spend $40 on this plain case on eBay
I flew about 7 batteries on Saturday. The first battery is always the worst. It's like the plane is broken or something. But then it (IE me) gets better.
I'm getting tired of the motor shaft overheating and melting the prop off. I lost 1 prop today. Maybe it was the inverted crash that loosened the prop but I think it was the heat. After flying a few batteries, the motor was "ouch, that's pretty darn hot" hot.
Weirdly enough, I keep thinking about going brushless... overpowered brushless. It's all those gas & glow jocks at the field. There I am just inching off the field and they're pulling verticals right after take-off.
I flew, I flew!
It's been forever. I flew for just 2 minutes when Stevie was here a few weeks ago. But on Saturday I got to fly almost a whole battery out. (I was a little short for time). It's so funny... The first time up, I thought the plane had some issue since I couldn't control it well. I brought it down and, yes, the prop was on backwards. A second time up and it still wasn't flying right. I looked and looked but the plane looked fine. So up a third time and.... well, it just took me a few minutes to get my wings back. I'm still not at 100%, but give me another 10 minutes in the air and I'll be doing flips in no time!
Wee! Check out the videos of these itty bitty Superfly electrics
Went flying with my neighbor, John E. and his grandson. He flew great for a 6 year-old!
The Sussex Air Show [tell more later]
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since October 23rd, 2003