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adhoc
05-30-2006, 06:21 PM
Got my Multiplex Twin Star II last Friday afternoon, just in time to build over the long (and mostly rainy) weekend. This is my second plane (first was the Easy Star), first aileron, and first non-RTF.

The build went fine; I took my sweet time on it, did most of the work Sunday and Monday afternoons. I forgot to order servo extensions, and the local hobby shops were closed on Memorial Day, so I cobbled some together myself. Glued the fuselage together before I thought to cut more space for batteries, but there's plenty of space already, as long as you use flat packs. If I have to I can do some cutting. Haven't painted/covered it yet...

I also got a Spektrum DX6, and in the spirit of minimizing the number of variables at a time, I put the AR6000 receiver in my Easy Star and flew on Sunday. Worked great, and I'm already planning to get another receiver for the Easy Star...

Everything was ready yesterday evening, rain clouds were (mostly) clear, wind had calmed down, by 8pm the park across the street had emptied of baseball and frisbee folks, so I decided to go for it. I was a bit nervous -- sure, I had gone through this with the Easy Star already, but it was RTF. This new Twin Star II was just a box/bag of parts a couple of days ago -- and now I'm going to toss it into the air and it is going to fly?!?! And it was heavier, and the twin motors made it sound/feel "bigger". And of course it was just a big unknown. I guess the warning NOT to glide test it didn't help, either -- once I threw it up in the air, I was committed! (There were also a few people watching, but they were quiet and respectful and staying at a distance, so they weren't too much of a distraction.)

But what the heck, I launched it. It powered up and away okay, but was immediately banking left, and climbing too steeply. I got it under control, but for the first minute or so, until I got it roughly trimmed, it was a handful. Seems obvious, but it flies *differently* than the Easy Star. The Easy Star is sloppy but forgiving, and sort of stupidly graceful. The Twin Star II is crisper, and its natural stall arc is *deeper* than the Easy Star (well sure, it is heavier!). And yet, when I pull the power off, it glides really well, almost as well as the Easy Star! I had flaperons set up, but they weren't adjusted right (I had elevator mix in the wrong direction), so I couldn't use them on the first flight at all.

AEAJR's advice about getting a computer radio was excellent! The DX6 is great with the Twin Star II. I really like the rudder mix with aileron (but may practice a bit with it OFF just to get a feel for coordinating turns manually). I also like the exponential, and the flaperons. Still getting used to the digital trims...

Flew again this morning. Man, I love this plane! It really wants to fly, and can fly both slower and faster than the Easy Star. Haven't tried any aerobatics yet; I'll work up to those slowly, and I'm definitely going to practice inverted on a simulator before I try it for real...

My biggest disappointment (if you can call it that) is that I'm going to need bigger batteries -- my Twin Star II is eating my new NiMH 7 cell 1100maH pack in 10-15 minutes. I got an ElectriFly C-35 for my ESC, so I can do LiPos.

I'll try to post pictures soon, although it is just plain white right now... I've got a color scheme in mind, but I'm still deciding between paint and Ultracote.

adhoc
05-31-2006, 03:25 AM
http://www.Wattflyer.com/photoplog/images/7204/medium/1_TS2_unpainted_Max_medium.JPG
(first time I've posted a pic, hope I did it right...)

adhoc
05-31-2006, 07:11 AM
I think I dodged a bullet tonight...

Went out to fly the Twin Star II in the short space between people finishing up baseball at the park and sunset. Opened the canopy, plugged in the battery pack, pressed the ESC button, light comes on, servos twitch. Replace the canopy, stand behind the bird, throttle up and back to arm the motors... but no beeps. Wiggle the controls, nothing. Pop the canopy back off, lights on the ESC button are dark. Hmm... Press the button again, repeat all of the above, dead again. Hmmm?

Bad battery? It is brand new, and just charged. I fiddle with the position of the electronics a bit, and it becomes clear that there is a loose connection somewhere. At this point, even if I got it working again, I'd worry about losing power in mid-flight, so the TS2 is grounded...

Carry it back home (just across the street!), set it up on the workbench, take the wings off and start checking ALL the connections. I narrow it down to somewhere between the battery and the ESC. Check several different batteries, and the answer is that those #@*! Tamiya connectors are flakey; the metal prongs can/will move around in the plastic housing. Unfortunately, the ElectriFly ESC just shuts off with even a momentary loss of power! Are all ESCs like that? Seems like they should try to recover and stay on...

So at this point I'm afraid to fly with Tamiya connectors anymore. And of course that's what I picked to standardize my battery connections. Poor choice in retrospect. I'm going to replace them ALL, with... something. Deans Ultras seem good, although they're a pain to unplug. But I'm good at soldering. The AstroFlight ZeroLoss look good, too. Or maybe Sermos. Too many choices... {grin}

Elfwreck
05-31-2006, 05:29 PM
Hey now,
Ultra plugs. They are The Way, The Truth, and The life. Do I sound lika a fanatic? That's fine by me.
They're cheap, lowest resistance of *any* plug on the market today, can handle more than one hundred amps without trouble, and you *can't* hook them up backwards. What could be better?

O.k., they can be a bit hard to seperate when fresh, but there's an easy fix. Put a pair together, tape a clothes pin to one side with the split on the split, get me? Then drill two 1/16" holes through everything. Now take off the tape and glue two short pieces of 1/16" music wire to the holes in the clothes pin. Now when you want to seperate a pair of plugs, slip the prongs on the clothes pin into the corrosponding holes in the ultra plug, squeeze the ends of the clothes pin together and `viola! Your plugs are seperated. Um, be sure you don't drill the holes so you short between the poles on the leads...
RobII

Grasshopper
05-31-2006, 05:39 PM
Good idea on the clothespin Elfwreck! I've changed everything I have to Deans. "They are the way". Chapter one, verse one.......the only one!

LannyG
05-31-2006, 10:15 PM
I use cheap circlip pliers to seperate mine. I like the clothespin idea. I just don't think you need to drill deeply in the Deans. My holes are less than 1/16" deep and work perfectly. I don't drill down to the metal. Just shallow holes in the plastic. I hope you can see them. With the circlip pliers the location of the holes in the Deans is not critical. I didn't think it up. Someone else did. I have Dean's on everything now that I can get them apart easily.
TwinstarII is a great plane.

adhoc
06-01-2006, 04:08 PM
Thanks to all for the tips, I'm definitely going to Deans Ultra (already converted one battery, works great)...

adhoc
06-05-2006, 06:31 PM
Finally finished the paint job, here are a few pictures...

http://www.Wattflyer.com/photoplog/images/7204/medium/1_TwinStar_actual_profile_reduced.jpg

http://www.Wattflyer.com/photoplog/images/7204/medium/1_TwinStar_actual_top_half.jpg

http://www.Wattflyer.com/photoplog/images/7204/medium/1_TwinStar_actual_bottom_half.jpg

LannyG
06-07-2006, 05:46 AM
Looks GREAT!
I've been using 8 cell 3300ma nimh batteries but I'm not so sure I like it that way. The batt weighs 17.7oz. Yes, it can handle the weight but I think it would handle more like I like with a lighter battery. And it seems to fly forever on 3300ma. More time than I need. Also the motors can handle the 8 cells I know, but I don't like the motors to get very warm at all. You can touch them but they are pretty warm...I feel I'd like a lighter battery so I ordered 7 cell 2000 nimh from cheapbatterypacks.com. That battery weighs just about 10oz. I feel the loss of a cell will be compensated by the loss of almost half a pound of weight.

adhoc
06-07-2006, 06:42 AM
Looks GREAT!
I've been using 8 cell 3300ma nimh batteries but I'm not so sure I like it that way. The batt weighs 17.7oz. Yes, it can handle the weight but I think it would handle more like I like with a lighter battery. And it seems to fly forever on 3300ma. More time than I need. Also the motors can handle the 8 cells I know, but I don't like the motors to get very warm at all. You can touch them but they are pretty warm...I feel I'd like a lighter battery so I ordered 7 cell 2000 nimh from cheapbatterypacks.com. That battery weighs just about 10oz. I feel the loss of a cell will be compensated by the loss of almost half a pound of weight.
Hey, I like yours, too!

I actually wanted more of a magenta instead of purple, but couldn't find the right color at the art supply place...

I'm alternating between a 7 cell and an 8 cell pack, both 1150 NiMH, both from CBP. Both poop out after maybe 15 minutes. So in my case I think I need to go bigger...

ragbag
06-07-2006, 11:08 AM
Thanks to all for the tips, I'm definitely going to Deans Ultra (already converted one battery, works great)...

Deans are the way to go. All of the hints I have been using for a while. Another is a light coat of grease, vaseline works but doesn't stay with you very long. Do not grease the connection side of the blade, only the other side. It is a great help also.
Sermos/Anderson are great plugs also, but everyone that uses them cuts them down to make them a little smaller, to me that is extra work that could be spent on your next craft.:)


Nice paint. might use your design on my Twin, it is still on the shelf.


.

redgiki
06-07-2006, 01:02 PM
Sermos/Anderson are great plugs also

The key advantage held by Sermos connectors is that you can trivially serialize your packs without using a special adapater. Dean's connectors require you to make or buy a serial adapater in order to, for instance, combine a 3S and 2S LiPo into a 5S.

Once you get into the big electric stuff, that kind of convenience is compelling; rather than carry around a bunch of different adapters, you just carry parallel adapters...

adhoc
06-07-2006, 04:06 PM
Nice paint. might use your design on my Twin, it is still on the shelf.
Thanks. Among many good bits of advice and inspiration on the web, I found this article especially helpful: http://www.jcrc.com/News/Articles/Article-ColorTheory.htm

I'd offer to share the painting plans, but what I ended up with on the plane is actually different than any of the three dozen different plans I came up with... {grin} But if you look over in another thread called something like "Twin Star II diagrams", you'll find blank images to draw your design on, if you like... In the end I didn't need the plans so much, because (as you can probably tell from the pictures) I favored 45 degree angles, which are easy to eyeball (but I checked with a ruler). The strips off of the engine cowls I did more by eye, but again tried to check with a ruler to keep them at least somewhat consistent...

adhoc
06-07-2006, 04:35 PM
I finally got my TS2 to behave...

Every flight so far I've felt it just doesn't handle right; sort of pivots or wanders around too much, wants to roll and/or nose up a lot. I wrote some of it off to just being a different airplane than the Easy Star I learned on. But even after several flights and adjusting the trims, I still wasn't comfortable with it. (For a while I was worried that I was getting uneven thrust from the motors/props, but I don't think so anymore...)

I had an intuition that maybe it needed the CG moved forward, and reading various forums around the web seemed to confirm that 70-85mm works (standard is at 85mm). So I added three 6 oz lead weights to the very front of the battery compartment, which moved the CG to around 77 or 78mm. I flew this morning, and now it has settled down. I don't know if I had the CG a bit aft, or if this plane just flies better with CG a bit forward.

Yet another reason to get some bigger battery packs; I think the dinky 2/3A sized 7- and 8-cell packs are too light and not enough capacity...

I think wind is another factor. I thought that since the Twin Star II is heavier than my Easy Star, it would be less sensitive, but wind definitely affects the handling...

I also got to try spoilerons instead of flaperons, and they definitely work better. Need to tweek the elevator offset, but it is mostly the way I want it. I think this is going to shorten my walks to the plane after landings... {smile}

LannyG
06-08-2006, 05:27 AM
Yes, it does sound like the Cg was a bit too far back. Perhaps the ideal battery would be something between my 3300 and your 1150. I've ordered a 2000 to see how I like it. It should be enough for weight if all the way forward.....I hope. I like lighter planes.
What holes do you have your ailerons set up with? I have outer at the servo and outer at the aileron horns. I think I may need to go in a hole at the horn. I better try it again though.
I like the spoilerons better than the flaperons but It still doesn't make that much difference to me. Comes in a little steeper, but another lever to push and something else to think about. I like things simple. Expo is alright but dual/rates are, to me, a pain in the rear end.
OH, 3M 2" clear stair tread tape is fantastic for the bottom of the fuselage! Its light, sticks like crazy, wears like iron, and protects from dents as well as scrapes. It appears to be white on the roll, but that is just the backing. The black and gray are too rough.

adhoc
06-09-2006, 04:25 PM
What holes do you have your ailerons set up with? I have outer at the servo and outer at the aileron horns. I think I may need to go in a hole at the horn. I better try it again though.
I'm outer at the aileron horn, and one in from outer at the servo. The ailerons won't swing as far as the manual recommends, so I may adjust mine, too. On the other hand, I feel like it has plenty of turning authority, so I may just leave it alone...

Air Trucker
11-07-2007, 02:14 AM
I use 11.1lipo 3 cell 2100 on mine it fly about 15 at half, But I;am also running 2829 Extra brushless 8x6 props. Great flier, it will do just about anything you want it to. Max