Shop our Airplanes Products Drone Products Sales
Thread Tools
Oct 12, 2011, 02:11 AM
Registered User
hklagges's Avatar
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
Sign up now
to remove ads between posts
Oct 12, 2011, 05:33 PM
Registered User
Quote:
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.
Oct 13, 2011, 11:51 AM
Registered User
Mtn_Commando's Avatar
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!
Oct 13, 2011, 12:09 PM
Registered User
capt soap's Avatar
Commando, Is it repairable? what survived the crash?? Lee
Oct 13, 2011, 03:42 PM
Registered User
Mtn_Commando's Avatar
Quote:
Originally Posted by capt soap View Post
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.
Oct 13, 2011, 04:05 PM
Registered User
capt soap's Avatar
Thrust vector noozels, and vector hardware??
Oct 13, 2011, 04:24 PM
Registered User
Mtn_Commando's Avatar
Quote:
Originally Posted by capt soap View Post
Thrust vector noozels, and vector hardware??
nope.
Oct 14, 2011, 02:39 AM
Registered User
hklagges's Avatar
Quote:
Originally Posted by Mtn_Commando View Post
I "decommissioned" it
Ouch Aua Aua !

Mtn_Su-Killa !
Oct 14, 2011, 12:52 PM
Registered User
capt soap's Avatar
Wow, some crash if the tail componets are damaged. PHOTOS?
Nov 18, 2011, 09:10 PM
Haul ass! Turn left sometimes
MiG-3 Reno Rocket's Avatar
Quote:
Originally Posted by Oger Lionel View Post

Those pics, ARE FRICKIN AWESOME! LOL GREAT JOB! THEY LOOK COOL!
Dec 21, 2011, 05:32 PM
Registered User
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...
Dec 21, 2011, 05:49 PM
Haul ass! Turn left sometimes
MiG-3 Reno Rocket's Avatar
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!
Dec 22, 2011, 03:52 AM
Pointy end at the front.
benjo's Avatar
This would work wicked as a pusher, one motor, one esc, no retracts, the thrust of a prop, imagine what it would fly like.
Dec 22, 2011, 02:47 PM
Dir_D_Redd
dirdredd's Avatar
That would be a big pusher. This guy holding that SU-47 has to be well over 6'1"
Dec 22, 2011, 04:52 PM
Pointy end at the front.
benjo's Avatar
Theres no problem with having a big pusher!


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product FreeWing 70mm F-35 w/ Thrust Vectoring bhatch21 Foamy EDFs 1864 Mar 21, 2017 04:45 PM
Discussion F-22 Raptor thrust vectoring scratch built twin ducted fan jet MikeysRC Foamies (Scratchbuilt) 2 Aug 05, 2009 11:29 AM
Discussion SU-35 or any twin EDF with thrust vectoring dash8pilot Electric Ducted Fan Jet Talk 11 Jul 21, 2008 07:32 AM
Discussion Wicked thrust vectoring twin turbine mig-29 video lavochkin Foamy EDFs 5 Jun 12, 2008 12:07 PM
Build Log Mig-35 Twin EDF w/ Thrust Vectoring tailslide5_0 Foamy EDFs 23 Aug 27, 2007 09:20 PM