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Old Jan 17, 2009, 01:15 PM
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Joined May 2007
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Quote:
Originally Posted by bladesmith
FYI aplus make an 800mah s2 35c rated lipo. I use these on my ep200 and they are hardly get warm. Flight time is 5 mins and no more. Flying hobby has these.
That makes sense. For the same mAh, 2C would give about 30% less flight time:

Super Hornet got 10min out of a 3S 1050mAh,
that should translate to 10min out of a 2S 1600mAh,
or 6.5min out of a 2S 1050mAh (35% less than 3S 1050mAh),
or 5min out of a 2S 800mAh which is what you're getting.

So far the back of the envelope calculations hold: for the same flight times, the 2S setup would weight the same as the 3S.

- Cesar
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Old Jan 19, 2009, 03:03 PM
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Joined May 2007
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Hi all,

Does anybody know what are the maximum battery dimensions that the T-Rex 250 will accept?

Here's the reason I ask: I built a spreadsheet to compute how much flight time any given battery would give, compared to the standard Align 850mAh/20C battery. The top spots are all TP ProLite batteries, and the two top spots are 2S batteries:

TP ProLite 2100mAh/15C: 152% flight time compared to Align
TP ProLite 2000mAh/12C: 151%

The rub is this: the 2100 is 100mm long (compared to Align's 58mm), and the 2000 not only is longer than Align's (65mm) but is also wider (50mm compared to 30mm).

So, does anybody know what fits?

- Cesar

For reference, here's the top spots (Align's flight time=100%):

TP ProLite 2S 2100: 152%
TP ProLite 2S 2000: 151%
TP ProLite 3S 1320: 147%
Zippy Flightmax 3S 1300: 139%
Outrage XP20: 138%
Hyperion LVZ 2S 2000: 136%
Zippy Flightmax 3S 1300: 133%
Rhino 3S 1250: 130%
Zippy Flightmax 2S 1800: 130%
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Old Feb 10, 2009, 03:11 AM
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Joined Jul 2004
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Quote:
Originally Posted by crusius
Hi all,

I'm still setting up for a T-Rex 250 build, and seeing as I already have a bunch of 800mAh 2S batteries, it would be nice (and cheaper) if I could make it work with those. I know of only one guy who ran the 250 on 2S, using the stock Gaui 200 motor. Anybody else ever tried it?

I was thinking about dropping a Tonic 5150 on the T-Rex and going from there. The only problem I can imagine having would be shorter flying times, as the T-Rex is (at least on paper) heavier than the Gaui, and the difference is not made up by a change from 3S to 2S and from the lighter 5150 motor.

Opinions/advice?

Best,

- Cesar
Hi! The cheapest way is to change the 15T gear to 22T gear (I use GWS, EPSC-9D4C, 22T, the center hole has to be enlarged to 2.5mm in diameter).
In addition, the ESC has to run in the normal airplane mode (4-1), but not in the soft-start mode (4-2).

pictures:
http://cid-b1ae5c3348e84d19.skydrive...0/DSCF2110.jpg

Indoor test, flying weight: about 310g; main blade: T-REX 250's 200mm blade
T-REX 250 powered by 7.4V, indoor test (0 min 33 sec)


Soft 3D, flying weight: about 280g because three servo has been changed. Main blade: EP200's blade
In fact, the soft 3D flying can be lasted for at least 4 minutes.
T-Rex 250, 7.4V, 倒飛 (2 min 5 sec)


Test fly outside the 5th floor; Main blade: EP200's blade
T-REX 250 7.4V test fly (2 min 45 sec)


camipro9
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Old Feb 10, 2009, 12:25 PM
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Get a HV ESC and run 10s 100mah batteries. lol
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Old Feb 10, 2009, 12:27 PM
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Quote:
Originally Posted by whilrybird
Get a HV ESC and run 10s 100mah batteries. lol
Markus makes a small 6s one for that game
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Old Feb 10, 2009, 03:53 PM
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I heard with the right motor and HV setup you can get some pretty impressive flight times. I spoke to someone from castle creations and they were saying around 20 to 30 minutes with HV, low mah batteries. Never tried it myself but then again it could be marketing hype.
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Old Feb 10, 2009, 03:57 PM
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Quote:
Originally Posted by whilrybird
I heard with the right motor and HV setup you can get some pretty impressive flight times. I spoke to someone from castle creations and they were saying around 20 to 30 minutes with HV, low mah batteries. Never tried it myself but then again it could be marketing hype.
does castle make a 6s or higher...smal esc?
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Old Feb 10, 2009, 05:20 PM
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I'm not sure, I know they have setup for 450 helis. I just threw that out there as an option to look into for longer flight times. If you guys find something that works for HV at these size helis let us know. I'm thinking at 6s you would not even need a 1amp esc.
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