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Old Oct 12, 2011, 03:11 AM
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Munich
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Very interesting data points - and surprising! How heavy is your aircraft? You must have saved a little weight by not using the TV units (3 servos plus a bit), but that should not make the difference. How heavy is your battery, please?

And btw I had the ailerons and elevators on individual unmixed channels, too.

Will you rebuild the gears or hand-launch?

Cheers and happy flying,
Henrik
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Old Oct 12, 2011, 06:33 PM
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Canada, AB, Calgary
Joined Oct 2010
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Originally Posted by hklagges View Post
Very interesting data points - and surprising! How heavy is your aircraft? You must have saved a little weight by not using the TV units (3 servos plus a bit), but that should not make the difference. How heavy is your battery, please?

And btw I had the ailerons and elevators on individual unmixed channels, too.

Will you rebuild the gears or hand-launch?

Cheers and happy flying,
Henrik
Almost 2.5kg with 690g battery (http://www.hobbyking.com/hobbyking/s..._6S1P_40C.html).
Static thrust 2.4kg.
It was slightly nose heavy within 5-10 clicks but that's without nozzles and chute.
I think what added to roll stability is that I halfed ailerons. Forward-swept wing has higher lift near the root than regular ones so playing with lift during turns is dangerous. Full-length aileron kills all the lift in one wing and causes stall on the other at some point. What happens next is tip-stall even at decent speed. And useless canards which are too close to CG on the model to do any elevator work but are really good at breaking airflow at wing roots add to this. You add some elevator during turn and plane suddenly stalls...
I connected canards to have around +-10 degrees at maximum.

I experienced that plane was self-leveling from the turns with stick in neutral and required barely any elevator for quite sharp turns. Didn't try any 3d. I flown it in loops at 60-70% throttle for about 3 minutes and the feeling was like a big fast solid plane with 2m wingspan. There was ~20km/h wind and su-34 I flew right before was quite searching up/down when against the wind. This one was going rock solid as if it's calm. I guess an extra kilo and more rocket-shape play the role.

I'll rebuild the wheels. Already ordered servoless retracts and metal legs from HK. Don't want to handlaunch it mostly for safety. One of my stock fans exploded before during bench test at full throttle and a couple of pieces penetrated through the foam, rest made small dents on the wall 3m away. The launcher person must have gloves and goggles at least.
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Old Oct 13, 2011, 12:51 PM
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United States, CA, Dublin
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Hello all,

My SU-47 is no more. I'm selling the SAPAC MB1 motors and fans, and the Castle 100A esc's. PM me if anyone is interested. Good luck with this beast, it's quite a handful!
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Old Oct 13, 2011, 01:09 PM
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dallas tx
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Commando, Is it repairable? what survived the crash?? Lee
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Old Oct 13, 2011, 04:42 PM
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Commando, Is it repairable? what survived the crash?? Lee
no crash. I "decommissioned" it (took it apart since I was moving out of state, it was too big to take with me). what's left is motors, edfs, esc's, rx, servo extensions, and nose retract.
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Old Oct 13, 2011, 05:05 PM
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Thrust vector noozels, and vector hardware??
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Old Oct 13, 2011, 05:24 PM
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Thrust vector noozels, and vector hardware??
nope.
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Old Oct 14, 2011, 03:39 AM
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I "decommissioned" it
Ouch Aua Aua !

Mtn_Su-Killa !
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Old Oct 14, 2011, 01:52 PM
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Wow, some crash if the tail componets are damaged. PHOTOS?
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Old Nov 18, 2011, 10:10 PM
Haul ass! Turn left sometimes
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United States, ID, Idaho Falls
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Originally Posted by Oger Lionel View Post

Those pics, ARE FRICKIN AWESOME! LOL GREAT JOB! THEY LOOK COOL!
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Old Dec 21, 2011, 06:32 PM
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Canada, AB, Calgary
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I have compared thrust on my RTF MIG and SU-47 I've build from kit with CS480-2500kv Cyclone power motors and was quite surprised. At full throttle:
MIG: 2.2kg thrust, 75amp
SU: 2.2kg, 105amp
(my elevation is 1.2km above sea level)

Both use stock fans and no TV nozzles or thrust tubes. The only explanation I see is that SU has an expansion area after edf where esc are located. After all, thrust is the difference of speed between air coming in and out of the plane times mass. So, looks like expansion and contraction in that area behind the edf causes 25% power loss. I'll add a 55mm coffee cup mod to nozzles and see how thrust changes.
I hope it's not due to Cyclone motors being less efficient than LX stock...
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Old Dec 21, 2011, 06:49 PM
Haul ass! Turn left sometimes
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United States, ID, Idaho Falls
Joined May 2011
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Quote:
Originally Posted by Sockrat View Post
I have compared thrust on my RTF MIG and SU-47 I've build from kit with CS480-2500kv Cyclone power motors and was quite surprised. At full throttle:
MIG: 2.2kg thrust, 75amp
SU: 2.2kg, 105amp
(my elevation is 1.2km above sea level)

Both use stock fans and no TV nozzles or thrust tubes. The only explanation I see is that SU has an expansion area after edf where esc are located. After all, thrust is the difference of speed between air coming in and out of the plane times mass. So, looks like expansion and contraction in that area behind the edf causes 25% power loss. I'll add a 55mm coffee cup mod to nozzles and see how thrust changes.
I hope it's not due to Cyclone motors being less efficient than LX stock...
YES! Please do post the results! I would love to see them and see what might be able to be done to mine as well. Thanks Sockrat!
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Old Dec 22, 2011, 04:52 AM
Pointy end at the front.
benjo's Avatar
Joined Aug 2009
663 Posts
This would work wicked as a pusher, one motor, one esc, no retracts, the thrust of a prop, imagine what it would fly like.
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Old Dec 22, 2011, 03:47 PM
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United States, GA, Clayton
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That would be a big pusher. This guy holding that SU-47 has to be well over 6'1"
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Old Dec 22, 2011, 05:52 PM
Pointy end at the front.
benjo's Avatar
Joined Aug 2009
663 Posts
Theres no problem with having a big pusher!
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