The EXTRA 300 EXT Build Thread

[Enterprise]

I have F150 with a 6.5 foot bed. The perfect size is a small 50cc that fits without taking anything off. My 78 extra is the biggest thing I can currently pull that truck off with, but I think the redwing slick I back ordered will fit that bill.

I can get my EF 88 edge with just one stab off and maybe the spinner, but it hogs the whole bed. I am pretty sure the 3DHS 92 edge will fit with the rudder off, but that is more work than the EF plane.

No doubt bigger flies better. I have a poll thread on budget 50cc versus high end 30cc. I am doing up my 90 Aerobeez with a "budget" setup and I will compare it to my 78 and 74 edge. Probably drag some of my friends and give them a sort of taste test with back to back flights on the different planes.

 

[Dr. Gonzo]

I will be glued to that build. I really like the aerobeez extra.

 

[gyro]

Have really enjoyed this build project so far AKf!

What's next?

 

[AKfreak]

To fly that pig... But as you know (but not the rest of the guys) I am using this plane as a reference. I am going to this plane as a test bed to develop a whole new line of planes for a (still un named) company in China. They want to bring a competitive line of 3D planes to market. I will be submitting origins designs and ideas changes to what they currently offer.

The great news is if they buy into my ideas, I will be able to put test planes in the hands of select pilots for design feedback based on how my designs fly. Some of my ideas may not be optimal, but they will be my ideas. I refuse to copy others hard work and call it my own. Also I refuse to be a part of a company that does that either. I have been given a commitment by the factory to develop original designs and bring them to market and do so for an affordable price.

To give you an idea, the plane I am currently building in this thread was $241 shipped ($35 was shipping) to my house. The new designs will be slightly more money as they will ave Carbon stringers, recessed wings roots, SFG's, cf tail and landing gear.


My biggest concern is weight, and control surface size/throw. Anyways, that's what's next with respect to the line of planes based on the plane in this thread.

 

[AKfreak]

So I am not sure what happened when I weighed the plane last time, but I was a,lost a full pound off of the actual weight. I was able to get within 5oz from my 10lb target AUW. I used the 2x 3000mah 6s 50C's but the problem is I cant make CG. The plane is way tail heavy unless I run two of my 5000mah 6s packs which put me at 11lbs 13 oz. Keeping things light is so hard when working with an un proven design. I mean there is no one that has already achieved a goal to copy from .

I can put put a CF tail wheel, and move the RX all the way forward, but I am about a pound off in the nose. To make CG with this smaller packs and I see no way to shift almost a pound of existing weight forward, to still stay light as possible.


GRRRR

 

[Enterprise]

I had a EG Raven that I originally did up electric. I had the same issue. I originally used a typical 30cc motor. Then I got a Hacker A60-5S, mainly because it was heavier. This was a 8S setup. I had a ridiculous amount of lead on the nose, plus the RX packs strapped to the motor box to get a barely neutral CG. I got frustrated and parked the airplane when the motor ejected, waiting on a new cowling (tried using a e-box instead of long standoffs, epic fail). Over the winter I converted it to a gasser, and I think still needed a slight amount of lead.

The moral of the story is that the plane is designed around a DLE-30. You have a couple of choices. First off I would find a heavy spinner. the farther the arm length of the mass, the more effect it will have. The CF tail gear will help as it is as far aft as possible. Also try a "heavy" prop like a APC.

One thing that I screwed up on the Raven is that it was designed around mini servos in the elevator, so downsizing weight there is another area to look at. I had tried karbonite Hitec digitals to save a few grams.

The CF pushrods on the elevator I suggested earlier will have an effect as well.

Just say no to vinyl aft of the CG.

Just say no to a pilot figure in the canopy.

Try relocating the RX LiFE batteries. The cool thing about them is that can charge them in the plane, so you can mount them on the motor box and just run some balance extension where you can hook up your charger.

The last resort is to change the motor box itself and extend it forward so you can move the batteries towards the nose farther. My builder buddy did this on a 3DHS 330SC after a crash for me.

 

[FlyMike1]

On the plane I'm building now, I mocked up everything first and it was tail heavy with 6s 5000. I have a 71" Slick that gave me the idea of joining the elevator half to eliminate a servo. Long story short is it worked, but I have yet to see how it does in the air. Waiting on the ESC then it will fly. Michael

 

[3dNater]

Yes, an extra servo in the tail does make a huge impact. It is really far from the CG.

 

[AKfreak]

I moved my Gecko 120 ESC to right behind the motor (mounted to the standoffs.) I then moved the Life pack to on top of the main packs and I am so so close. I need to build some sort of a CG machine. thinking of two small light stands with rubber stoppers on top. With my fingers, I am 3/4" rearward on the manufacturer 4.45" cg mark. I have heard that for a 3D plane a slightly aft CF is desirable (any comments). Also I think 3/4 of an inch aft cg will not make it so that I cant get the nose down.

Mainly what I'm after is the plane can be trimmed to fly level upright and inverted with out any stick input at 1/2 to 3/4 throttle. I find that makes flying so much more easy for me. If the nose is always requiring me to keep forward pressure on the stick in inverted flight it looks really sloppy and makes me nervous to get to low when flying fast (I have fat fingers sometimes).

I will be replacing the tail wheel and elevator push rods with CF. I am so ready to fly this baby and I am so so close. But its waiting time, as I need to order a new tail wheel. Any recommendations on where to get the CF push rod/ball links. And as always guys, thanks for taking time to help me figure this thing out. AKf

 

[SnowDog]

lose the tailwheel altogether...put some sullivan goldenrod (the yellow, inside part) on the tail of the fuselage (in the shape of a "U") and go fly!

at least that will get you in the air until you get a real tailwheel.