Originally Posted by Kenzo77

Aros, What are those mate? Are those the bungee thingy? What if the nose of the plane is heavier? Won't it dive back directly to the ground?

These are the bungee systems used widely with gliders/sailplanes with no power. They uses these to quickly gain altitude to begin chasing thermals. I used them for years when I started out in RC sailplanes. It should work great for EDFs as well. The key is to make sure the hook that the bungee attaches to on the jet is not too far forward or too far aft. The perfect placement will guarantee success. In fact, if done correctly I shouldn't even have to throttle up until the bungee releases due to the inertia of the bungee pulling it skywards.

And once it releases, I will have all the altitude I need to throttle up and deal with any trim issues. The most important thing is my pitch and roll sensitivities. You want to keep some up elevator throughout the process and relax it once the bungee has reached it's max altitude. From there the ring slides off the hook and you're on your own.

I won't need the full 250 feet altitude of course. I will cut the string and bungee to accommodate roughly 100 feet altitude which should be more than enough to launch the SR-71 successfully (assuming my CG and throws are correct).

ok on the radio, I was looking at the one above in the 3rd picture and it did not look so, but the futaba radio is good...
You still need a lot bigger battery... I had to do a lot of cutting and moving mine back for the cg to be right...my battery alone is one pound.....

OK guys dug out my SR71 kit :-)

Sounds good aros! Would love to have those but would need a field or a soft ground to hook it up right? What's the price and any links for it?

Yes it requires any grass field or dirt surface that you can hammer a spike into the ground easily. Here's the link for the High Start:

http://www3.towerhobbies.com/cgi-bin...?&I=LXYXK4&P=7

Here's a quick demo I made tonight of the SR-71 Blackbird that comes with the Expansion 7 pack for my RC sim RealFlight 6. Notice the scale stab/rudders and whale tail that acts as the elevators while the elevons are for aileron control only. I wonder how our birds would fly if these were the mods we did to them.

SR-71 Blackbird RealFlight 6 (Expansion Pack 7) (1 min 10 sec)

Heya guyz,

any idea where can I get the esc programming card for my esc? thanks guys.

Just did a read out on the twin, only 1300+ watts at 93amps, the motor is rated 1100watts each, or its normal for twin running engines? Or I should run seperate batteries?

Originally Posted by Kenzo77

And joe mate, can you explain on how you modded the whale tail? I did a mistake of cutting it too huge of a surface, and also the links to the parts to get the items u use for the mods.

OK, found a bunch of shots of the whale tail...I went with one servo inside...lighter, saves power and no drag if kept to one servo...all the items are from my scrap box and the servo and servo connector is standard fare at your LHS.

The servo horn on the whale tail end of the pushrod is a wheel collar that I soldered a brass horn to...this was to make it adjustable with the little setscrew. I would do that a lttle different...epoxy a ply horn instead, it can't slip, more simple, less weight and it really doesn't need to be adjustable, which can be made at the servo end of the pushrod. The way mine is now, I'll have to cut two hatches if either end slips.

Joe

Originally Posted by Aros

Notice the scale stab/rudders and whale tail that acts as the elevators while the elevons are for aileron control only. I wonder how our birds would fly if these were the mods we did to them.

Not good, as this model needs the entire trailing edge to move in elevator command to make it responsive in landing/takeoff phase.

Rudder mods...this is a easy way for rudders, but not scale.

Scale... full floating/flying rudders would be a awesome mod. I was concerned about going in the 100mph region with these kind of rudders...it's all that rudder in front of the hinge point that gives me pause. Example, a small board held edgewise in front of you going 90 is tougher to hold than letting it trail behind you. One of you guys should try it, just make sure there's video so we can assess the...

Joe

Speed sensor...this would be almost the same with a telemetry model...you don't have to be as particular where the sensor goes on that kind of set-up, but the pitot tube install would be the same.

Joe

Originally Posted by redlite

Not good, as this model needs the entire trailing edge to move in elevator command to make it responsive in landing/takeoff phase.

Yeah that was what I was thinking too...Looks sweet but not practical for this model.

Fantastic mods redlite. I'm going to copy your single servo whale tail mod. That pitot tube is sick!

Originally Posted by redlite

Speed sensor...this would be almost the same with a telemetry model...you don't have to be as particular where the sensor goes on that kind of set-up, but the pitot tube install would be the same.

Joe

Joe,

Thanks for loading the pics of the pitot tube installation... I'm on a business trip right now, but got notification that my speed sensor package arrived at my house yesterday. Can't wait to get home and start cutting some foam!

Since you've already installed one... anything you'd change about your installation? How'd you handle the epoxy... just apply it from the rear after the pitot tube was installed? Obviously, you don't want to get any on the pitot/static ports...but you want a good, snug installation also.

Thanks,
Sully

Joe,

those are some awesome mods mate! love what you did to the amazing bird, have you flew it yet?

Can you please kindly add the links for the parts you used for mate? i have trouble finding them online. The hinges looks good!

And guys, any idea where can i get the programming card for this ESC? - http://www.hobbyking.com/hobbyking/s..._100A_ESC.html

Thanks guys!

Originally Posted by Cobra68

Joe,
Since you've already installed one... anything you'd change about your installation? How'd you handle the epoxy... just apply it from the rear after the pitot tube was installed? Obviously, you don't want to get any on the pitot/static ports...but you want a good, snug installation also.

Thanks,
Sully

Hey Sully,

I embedded thin CF rods around the nose later after a couple on 'hits' during transport that softened the foam. Lay them parallel with the centerline in a radial fashion. They were thin and about an inch long, I think there were two or three on top and the bottom. Really stiffened the nose area up. Filled with lightweight spackle, let dry and sand to finish surface, then soaked the spackle in thin CA to harden up, sand again, prime and paint...

You have mentioned a couple of good points above, so study the pics and it's really an easy mod.

Joe

Originally Posted by Kenzo77

Joe,

have you flew it yet?

Can you please kindly add the links for the parts you used for mate? i have trouble finding them online. The hinges looks good!

And guys, any idea where can i get the programming card for this ESC? - http://www.hobbyking.com/hobbyking/s..._100A_ESC.html

Thanks guys!

Yep, two years ago, Bighead bought the model and has flown it since then.

I didn't buy any special parts for the whale tail mod, just bits and pieces as you can see in the pics. Hinges are GWS paper hinges...I found something better, FedEx envelope paper, impossible to tear and takes CA very well.

I looked at your link for the ESC and it states that this unit is a plug and play and has limited programmability.

Joe