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Old Feb 19, 2012, 11:44 PM
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Originally Posted by Cobra68 View Post

I can't seem to stop spending $$$ on this build.... don't tell my wife, but I also just ordered the EagleTree pitot tube that Redlite had/has in his bird .
Demanding mistress in so many ways...

The pitot tube was the best upgrade for assessing each flight. For example, the last few flights last weekend were with the camera mount and keychain camera (problems with the cameras, but the mount works fine) resulted in a 17mph decrease in top end...71mph versus 88mph clean. I wouldn't have guessed such a large drop in speed, but the pitot tube reports the results. Only thing better would be real time telemetry on the transmitter...hmmm, more $$...rats...

Joe
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Old Feb 19, 2012, 11:45 PM
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United States, WA, Ravensdale
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OK... just glued the EDF's and thrust tubes in. Here's my advice...

1. Test fit EVERYTHING without using ANY glue
BEFORE YOU GLUE ANYTHING!!!! Ensure that your motors are both rotating in the right direction, and assuming that you are running Don's RC Wicked motors and soldering your motors directly to your ESC's, that your ESC wires are cut to an appropriate length to allow for thrust tube installation (DON'T CUT MOTOR WIRES TO FIT... THAT WILL VOID YOUR WARRANTY)
a.) Make sure thrust tubes have the appropriate cut-out for the motor wires
b.) Make sure that the set-screw hole on the EDF housing is accessible when the fan is glued in place (otherwise, pull the fan off, rotate the motor on the EDF housing and reset so that set-screw hole is accessible when fan is glued in place how you want it
c.) Use nothing faster than 30-min epoxy so you have time to move things around
d.) Practice gluing and assembling the parts before actually mixing up epoxy

2. Put your thrust tubes three-quarters of the way in... then spread the glue for the EDF unit (Personally, I used 30-min 2-part epoxy). I also spread a light coat of epoxy just behind where the thrust tube was going to meet up with the EDF unit, since that was an area that I wasn't going to be able to apply any tape to hold it in place.

3. Drop the EDF unit in place and rotate so that the wires fit the way you want them to (a proper test-fit is very important here... this is NOT the time to figure out that you need to re-solder 3 different connections)... but make sure that the prop-shaft set-screw hole is accessible (in case you ever need to swap out a fan, and don't want to have to pull the whole EDF housing out).

4. As you are twisting the EDF unit in place, start sliding the thrust tube forward so that the cutout for the wires lines up with the cutout in the foam at the ESC bays.

5. When you are happy with the general layout of the fans/tubes, drop a bit of epoxy under your ESC's and glue them in place.

6. Take a disposable shop brush and rub some 30-min epoxy in the exhaust ducts... then slide your centering rings up the exhaust tube to make a snug fit around the thrust tube. Hopefully you have already test-fit this multiple times, and it's just a matter of dropping in a bit of glue and sliding the rings in place.
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Old Feb 20, 2012, 12:02 AM
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United States, WA, Ravensdale
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Originally Posted by Aros View Post
I could really use a YouTube video of the thrust tube installation. Any takers?
Man... just a bit too late with that request... I just finished putting mine in! Then again... I don't currently have a good video camera (at least not a digital one... mine still records to TAPE!)... unless the fellas on the blog wanna kick in for a video camera like they did for Fuse #7...

Just kidding... I'm honestly not pandering for a new video camera... I just got done telling the wife that she was gonna get one as a President's Day gift so that she could videotape the maiden of Habu #2... so it's really up to me at this point find a good one... but I will take any recommendations, if anyone has a favorite...
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Old Feb 20, 2012, 12:15 AM
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Originally Posted by Cobra68 View Post
Man... just a bit too late with that request... I just finished putting mine in! Then again... I don't currently have a good video camera (at least not a digital one... mine still records to TAPE!)... unless the fellas on the blog wanna kick in for a video camera like they did for Fuse #7...

Just kidding... I'm honestly not pandering for a new video camera... I just got done telling the wife that she was gonna get one as a President's Day gift so that she could videotape the maiden of Habu #2... so it's really up to me at this point find a good one... but I will take any recommendations, if anyone has a favorite...
Sorry to Aros, i had all mine tape in with fibre tape already, but thats a good write up Cobra, it is a very good explanation on it.

Plus mine was slightly different as my EDF is mounted closer to the intake, so the tube was way too long almost 30cm in length.
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Old Feb 20, 2012, 12:22 AM
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NICE job Cobra!! Your thorough explanations AND photos is a blessing!

I will refer back to your post when it's time for me to add everything together. Thank you!
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Old Feb 20, 2012, 12:30 AM
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Okay quick whale tail question...At the risk of sounding like a complete idiot, what is the configuration for them when given aileron inputs? Do they act as ailerons and the port side goes up with left aileron and starboard side down and vica versa with right aileron? Or do they stay at neutral and are only active for elevator response? Curious of the mixing...
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Old Feb 20, 2012, 01:06 AM
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Originally Posted by Aros View Post
Okay quick whale tail question...At the risk of sounding like a complete idiot, what is the configuration for them when given aileron inputs? Do they act as ailerons and the port side goes up with left aileron and starboard side down and vica versa with right aileron? Or do they stay at neutral and are only active for elevator response? Curious of the mixing...
Aros,

i am doing the whale tail mode as well, i am actually gona mix them with both the elevator and aileron with, just hoping to fine tune the throw properly.
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Old Feb 20, 2012, 01:24 AM
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If memory serves, the real Habu utilized the whale tails in conjunction with the outboard elevons. So whatever the port side outboard elevon did, the associated inboard elevon would follow suit. Same with the starboard/outboard/inboard elevons.

Habu Aficionados please step in if I am incorrect here...
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Old Feb 20, 2012, 01:32 AM
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If memory serves, the real Habu utilized the whale tails in conjunction with the outboard elevons. So whatever the port side outboard elevon did, the associated inboard elevon would follow suit. Same with the starboard/outboard/inboard elevons.

Habu Aficionados please step in if I am incorrect here...
Aros,

mate i just saw this video, it seems that the aileron is not mix with the whale tail, its seperated.

Check it out -
SR71 INBOUND RC JET (2 min 57 sec)
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Old Feb 20, 2012, 01:52 AM
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Originally Posted by Aros View Post
Okay quick whale tail question...At the risk of sounding like a complete idiot, what is the configuration for them when given aileron inputs? Do they act as ailerons and the port side goes up with left aileron and starboard side down and vica versa with right aileron? Or do they stay at neutral and are only active for elevator response? Curious of the mixing...
Great question... I was just pondering the same thing and was gonna ask Redllite or Bighead how they had theirs set up.

Regardless, I think I'm going to give each servo its own channel... L-Elevon; L-Elevator; R-Elevator; R-Elevon. That will at least give me the option to have some differential speedbrakes at some point if I so desire (in addition to the ability to change the way the whale-tail works without having to cut the fuse open to un-do Y-harnesses)... plus one channel for the LG retracts, one for NWS and rudders, one for the pitot tube power, and the 8th channel for the ESC... and that will use up all ports on the 8-ch receiver that I plan to use.

I think I'll try and set it up so that the elevons work as normal, doing both pitch and roll inputs. The inboard "whaletail" elevators will be for pitch control only. As for surface deflections... I think I'll go with the numbers that The Don had put in this blog... I think it was 15mm for roll control and 25mm for pitch control. Obviously, with the whale tail, that will give me some extra pitch authority, but with careful use of dual rates, I think I can negate the risk of having it be too "pitchy". If it looks like it's gonna be too much, I'll cut it down to 20mm for the first flights and see how it handles...
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Old Feb 20, 2012, 03:14 AM
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Originally Posted by Cobra68 View Post
I think I'll try and set it up so that the elevons work as normal, doing both pitch and roll inputs. The inboard "whaletail" elevators will be for pitch control only. As for surface deflections... I think I'll go with the numbers that The Don had put in this blog... I think it was 15mm for roll control and 25mm for pitch control. Obviously, with the whale tail, that will give me some extra pitch authority, but with careful use of dual rates, I think I can negate the risk of having it be too "pitchy". If it looks like it's gonna be too much, I'll cut it down to 20mm for the first flights and see how it handles...
I think you are dead on...Kenzo's video underscores that the "whale tail" is elevator/pitch response only.
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Old Feb 20, 2012, 03:28 AM
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Since the plane is roll sensitive (crazy sensitive) and if the whale tail moves in roll too, then you'll have your hands full...not much fun...however, the plane is poor in pitch response, especially with the extended fuselage, so having the entire trailing edge move on that command makes for a relaxed flight, mostly in the takeoff/landing phase. No problem of it becoming too pitchy, just the opposite, the mod reins it in. I would not recommend the whale tail move at all in roll command. IMO. We slave ours to the elevator. The rudders are for a model with landing gear and aren't really needed for belly scratchers...

The mods were posted around page 17 of this thread.

Your numbers look good C68...looking forward to your flight report.



Joe
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Old Feb 20, 2012, 04:40 AM
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Joe your word is gold here. Whale tail is for pitch only. I won't soon forget it.

Should have known. The key to this bird is minimal roll, max pitch.
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Old Feb 20, 2012, 06:53 AM
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You guys are pretty much on the money. Although I have done it both ways, the whale tail is mainly to aid in pitch. If they control roll as well, it will roll even more like a drill. There is a transmitter mix that will give you more elevator than aileron, I would suggest that premise. You could seperate the whale tail for elevator only, using the ailerons for both. Either way works.
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Old Feb 20, 2012, 07:44 AM
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Wow.. what a video....that was one squirelly bird...but it sure was beutiful...

Does everyone agree that the whale tail mod a neccessity??
I have not done that yet but after all the talk I think I might..
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