volkan

I bought a twinstar with RC3000 8.4V Nimh
i few it, aliron servo was not responding and it crashed video at
[link=http://www.volkan-dil.co.uk/fs.htm]http://www.volkan-dil.co.uk/fs.htm [/link] under the name My Twinstar Crash.

i had its scond flight today, there was not enough power (i trickle charged it all night)
i launch was ok, then motors cut, bought it in and hit a tree 2 cm off the ground, makeing a massive dent in the wing

tell me what you think

MrMulligan

My Feedback: (314)

I've been flying one for more than a year. I use the standard motors with a 30 Amp ESC and a 7 cell 1400 mah NiCd pack. It flies great. I get about 6 or 7 minutes of flying time. It launches beautifully with a hand-launch. The only alteration was to change the props from the included ones to 5x4.5 APC's. I think it flies better with this setup. I want to add more aileron throw as I can't get it to roll. It does beautiful loops and great low passes. The sound of the twin. Maybe you ought to try a lighter pack. You say you trickle-charged it. What was the charge rate? The C-10 rate for overnight charging for that battery would be around 300MAH. It's possible you didn't have enough power to fly from the trickle charging.

volkan

i have a jeti 30 amp, the charge rate was 0.2a. on the hitec CG340
i might upgrade to a 9.6v pack, this might solve the problem.

Hegasis

you have under powered motors and you were over controlling. lay some glass on the wings and try again

A1RENCH

Here's the problem! (I think). The Hi-Tech CG-340 has a 2-hour safety shut off. That is, 2-hours after the button is pushed to start the charge cycle, the charger shuts off, even if the pack is not peaked. So this charger is best suited for fast charging packs, and not trickle charging. Step up your charge rate to insure the pack will be charged within 2-hours and try again! Ni-cads can usually be safely charged at 2.25 times the MAH rating, and NIMH at 1.25 times. Good Luck!
Happy flying,
Bud

csisfun

Huh!

And i thought NiCD's were good up to 3C, and nimh up to 2C

volkan

thanks guys i will try that, the motors i use is standerd speed 400's which came with the model.
and i can exactly take them out, they are epoxyed in!

Scar

My Feedback: (3)

Just one more thing, you may have done the same as me and just taken the plane out & flown it.

After two crashes, with what seemed like very low power, I remembered that a lot of posts mention motor breakin. Well, I had mine epoxied in, like you, so I couldn't break 'em in submerged, like some recommend. So, I simply ran the batteries down about 3 times, recharging in between, with the motors running full throttle sitting on the floor. On the third flight, no crash, and it actually launched from my hand with no wind.

Mine will loop, although it helps to dive a bit first. Rolls are your typical high wing stagger, but it will roll. Seems like it flies very slow, until I come in for a landing, then it doesn't want to slow down!

After it seemed to gain power, after motor breakin, it was a whole different plane. Nice for winter flying, when I don't want to deal with glow fuel.

Good luck,
Dave Olson

volkan

i will try that

Matt Kirsch

My Feedback: (21)

Scar,

What you did was "break in" the battery, not the motors. NiMH need 2-3 cycles run through them, along with proper charging, to achieve peak performance. Ideally, you want to do this with a proper computerized discharger, but in a pinch, it can be done on the plane. The down side to running them down in the plane is that you can cause heat buildup in the motors, and premature motor failure.

A motor break in requires a low constant voltage, like that from 2 D alkaline cells, to round out the brushes so they make maximum contact with the commutator on the motor. This only marginally improves performance, but does wonders for the longevity of the motor. Running the airplane on the ground does little to break in the motors, as the high voltage and low contact area of the new brushes causes a lot of sparking (arcing). The arcing is like a welder, and burns both the surface of the brushes and the commutator.

volkan,

Your initial problems most certainly resulted from a badly charged battery. The CG340 will charge NiMH at 1.5 Amps. Use this maximum charge rate to charge your cells now that they've had a couple of breakin cycles.

Scar

My Feedback: (3)

Matt said :
Really? Wow, ya learn something every day! I'm glad I looked back at this thread! Actually, it seems, the more I learn, the more I learn I DON'T know! Ha!

Thanks,
Dave Olson

cassidy

My Feedback: (5)

My flying buddy uses an 8cell pack of cp1300's. Last week we had a nice day (sun was out temp was 42) so we went to our club field that was snow covered.
He did a few hand launches then I convinced him to take off from the snow. Off in 20 feet and flew great. Loved it so much I am getting one but I have a couple of small brushless motors that I may try.

volkan

not fed up any more, it flew great, it was a bit lively (so my instructor says). But the problem was the 2hr cut off,
thanks guys

Matt Kirsch

My Feedback: (21)

I love hearing success stories