Durafly Vampire build.

[Skyboom]

If anyone has any tips or advise on this build please let me know. I can't believe it came without instructions. They gave me 5 little bill boards of Hobby King decals instead.

[JamesonC]

Instructions here: https://cdn-global-hk.hobbyking.com/...406-manual.pdf

[Skyboom]

Cool. Thanks. Seen videos where they've added a rudder system. Was wondering about a cross bar. Between the vertical stabilizers. That would operate both rudders. Theoretically.

[xviper]

It doesn't really need rudder unless you are landing in a cross wind a lot of the time and even then, it does quite well. It was designed as a "bank and yank" and it flies that way just fine without rudder. But if that's what you want, do it.

[Skyboom]

I just want to get it in the air for now. The rudder system can wait. Ran into a hiccup with control rods. Have to file the ends to fit control horns on all of them. Wish they'd make the proper size, but that would be to easy. lol

[chipset35]

Let us know what you think of that aircraft.

[Skyboom]

Well, I tried to fly it today. Wouldn't take off the grass runway strip. I could try putting a bigger nose wheel on and not retract. One pilot mentioned useing a carpet for take off. It was tail heavy, when we hand launched it. Had 2200mah 3 cell shoved as far forward as possible. It's a work in progress now. Maybe a more powerfull motor would help it performe better.

[xviper]

Well, I tried to fly it today. Wouldn't take off the grass runway strip. I could try putting a bigger nose wheel on and not retract. One pilot mentioned useing a carpet for take off. It was tail heavy, when we hand launched it. Had 2200mah 3 cell shoved as far forward as possible. It's a work in progress now. Maybe a more powerfull motor would help it performe better.

This is a 4 cell plane. A 3 cell is barely adequate. I use a 4s, 3000mah, Graphene and it's located under the strap in a mid position and it balances perfectly and has so much power, it'll blast off my rough, weedy grass in very short distance.

[Skyboom]

Oh cool. I'll get the bigger battery then. Seems like xviper and others here are more knowledgable than everybody at are club.

[xviper]

BTW, it's the same battery that I use in my V-22 Osprey, just like the one in your Avatar. (I've just ordered my second one in white.)

[Skyboom]

I just ordered the STRIX Goblin. A good high performance aircraft. Should be here next week.

[xviper]

I just ordered the STRIX Goblin. A good high performance aircraft. Should be here next week.

I had one. It takes the same battery, too. Mine was hard for me to launch. It tended to torque on me after throwing it. I threw it into the ground a couple times. Then one day, I did a loop in high cross wind and it went behind me and buried itself in the dirt. The powertrain is now pushing my Arctic Cat.

[chipset35]

This is a 4 cell plane. A 3 cell is barely adequate. I use a 4s, 3000mah, Graphene and it's located under the strap in a mid position and it balances perfectly and has so much power, it'll blast off my rough, weedy grass in very short distance.

I might just get it and use my 3200 mah, so I dont have to buy another battery.
Grass runway performance is a must for me.
Uh oh...I just watched a few videos...why does it always veer left during roll out?

[xviper]

I might just get it and use my 3200 mah, so I dont have to buy another battery.
Grass runway performance is a must for me.
Uh oh...I just watched a few videos...why does it always veer left during roll out?

Is your 3200 a 4 cell? If it is, it should balance the plane quite easily withing the battery tray area. I haven't watched that many vids of this plane. I just know what mine does. I suspect that people are trying to do "scale" take offs and that gives the plane too much time to "go its own way". Remember that the steering system on this plane is very "Mickey Mouse". Those 2 cables get sloppy very quickly, even without any operational vibrations and shocking. The nose wheel till tend to veer towards its favorite side and take up the slack of one of the cables. Corrections must be immediate and deliberate or it'll just keep going where it started going. With mine, I know from ground taxi tests which way it wants to naturally go. When I'm ready to take off, it's "pedal to metal" right from the get go and I anticipate which way it's going to veer and counter it before it goes too far. Once it's got some good airspeed, even on the ground, the fixed rudders still provide some directional guidance. I haven't flown mine since it snowed but I do recall that mine will get the wheels off the ground in about 50 to 75 feet. By forgetting about the "scale" take off, the thrust of the fan tends to drive the plane straight ahead. Don't give those wires a chance to allow the wheel to react to the ground contours.
Also, do some "testing" up high. You may find that, depending on how you let the glue set on the tail booms and the amount of elevator reflex you have (this plane needs a few degrees of UP). When you go from low rpm or cruising rpm and suddenly pour on the coals, the plane could take a nasty dive. When close to the ground, don't increase throttle too aggressively.

[asesso]

Is there a definitive answer as to where the CG is on this aircraft? I have just finished a build and want to make sure I use the correct CG

[xviper]

Is there a definitive answer as to where the CG is on this aircraft? I have just finished a build and want to make sure I use the correct CG

Being how this thread is 3 years old, it's hard to say if HobbyKing has revised the CG on this plane. I haven't flown one in a year and a half. Hopefully someone still flies this plane to this day and can comment. The original issue had the thing so nose heavy, needed so much UP elevator that if you eased off even a little bit on the elevator, it would plow itself into the dirt. My second one was much better. Use high rates and take it up high to trim. If it looks like it's not going to trim with all the trim you've got, land it ASAP but do a belly landing. It's going to come down fast and having the wheels down may prove a poor choice.