cx2 flying outside!!

[helimech66]

I have been able to fly my cx2 outside with 0 to 5 knots of wind but it took a while with upgrades and mods. It is the cx2 with the nascar theme. I replaced the aft body with a carbon fiber t/b (homemade) I found some 180 motors with replaceable brushes that have more power than stock. I move the servo link to the 3rd hole on roll and pitch sides. the landing gear is stronger than stock. drilled a hole in the 4in one for cooling and found a 850mh amp batt (megapower) for 16.00 dollars which helps. I made my own flybar with smaller weights and cut the length down. all alum except blade grips. No joke I can clear trees 50-60 feet high but be careful if you want to try this because winds are decieving above tree tops. good luck !! :glasses2:

[txflyer]

start up some cx pylon racing

[helimech66]

Whats pylon racing?

[Kindling Maker]

That is too cool I am goingto have to give it a try. Did you get your tail boom kit from Boomtown.com or what?

[helimech66]

I purchased the items for the tailboom from a local hobbyshop. I pretty much fabricated the assy. the main rod is carbon fiber and the lower thinner rods are metal. the length and attachment points are perfect for my set up but might vary for you and your set up. p.s. I noticed your location is mosul, soldier or civ? I'm a soldier myself was in balad 1 1/2 years ago. :glasses2:

[Kindling Maker]

I am a Civie, But i have been here for Three years. I was here during Desert Storm and this is just finishing up what I started. Boomtown has a kit that puts the Boomtail on. Does the tail help alot. It seems like it would really make it easier to fly in the wind because it gets rid of the side area of the stock tail.

[Kindling Maker]

what was the purpose of cutting the Flybar down? Was it for response time or a higher head speed?

[txflyer]

i would think it would help to quicken the cyclic. shorter flybar means less natural forces to over come, and less rotating weight. easyer for the flybar to do its thing.. if i am worng i will be deleting this poist.

[Kindling Maker]

that is what I was thinking but I wanted to ask

[Kindling Maker]

Well we are also working on a way to gat more air into the nose of the CX2 we are looking at putting scoops on it, it will work for forward flt but not in hover. Rememdber that we are in 119 degree temps so keeping everything cool is really important.

[helimech66]

Yes and Yes to your questions. With almost no surface area on the t/b the rotor wash flows through instead of deflecting off the original body.The shorter flybar has cp weights and makes for more responsiveness and I believe lenthens flight time because of less resistance. I only cut the bar down the length of and old weight. Use a dial caliper to ensure the length from the center to end is exact on each side. p.s. I am at the 4th hole on the pitch servo so far so good.. :glasses2:

[Fan M]

Hello Helimech


Sorry, I didn't understand

How much did you cut away?
Thanks

[Kindling Maker]

well al rity yhen I am on the second hole and I am having problems with the blades slapping. How are you dealing with that. and what motors are you using and where did you get them.

[helimech66]

If you have those black flybar weights that came with the cx measure the length and that is the amount I cut the flybar down on each side. I use to slap blades all the time and I found that to many aggressive inputs at once causes that. these acft have limitations such as real ones do it's just a question of how far you take them. 3rd hole for the roll servo is more than enough for turning through a light breeze but I experimented this weekend on the 4th hole for the pitch servo and all was well just remember if you go full pitch on the stick you can pick up speed so quick you might not be able to fly out of a hard turn. If you want I,ll post a video of what I have been able to get this heavy modded acft to do. The motors came from www.slick zero.com xtreme 180 ball bearing 16.00 the brushes are replaceable. get a heat sink they warm up but are worth every penny. :glasses2:

[teshreve]

I have shortened the flybar and I have reduced the weight on the end (up to removing the brass weights from the flybar and just leaving the rubber).
The effect is similar, but I find less weight with a regular length flybar to be better.
With no weights, hovering will be almost impossible as it is very unstable. But, if you fly outside and like to boogy, give it a try. It is almost impossible to blade strike and 90 degree banks (or better) are possible.
I am using a DX7 radio and this seems to help by limiting servo throw to what is usable (especially when you start using the outside holes on the horns).

[flynn]

I am still new at this and am trying to understand the dynamics of the CX rotors, so help me with this. The flybar is attached to a floating set of blades. What is the flybar's function on this. How do the two rotar sets interact with each other. I do not understand how the flybar does mch of anything.

thanks
Flynn
















I have shortened the flybar and I have reduced the weight on the end (up to removing the brass weights from the flybar and just leaving the rubber).
The effect is similar, but I find less weight with a regular length flybar to be better.
With no weights, hovering will be almost impossible as it is very unstable. But, if you fly outside and like to boogy, give it a try. It is almost impossible to blade strike and 90 degree banks (or better) are possible.
I am using a DX7 radio and this seems to help by limiting servo throw to what is usable (especially when you start using the outside holes on the horns).

[Fan M]

I think the flybar works as a mechanical gyro. The dynamics of a gyro are quite complicated.
The CX2 with the stock flybar returns into a stable hover when you release the cyclic. This helps a lot when you start learnig to fly but makes the heli less responsive.

[flynn]

OK, but how does a shorter flybar, or less weight effect response. The flybar is not connected to the rotor being manipulated by the cyclic controls. The lower rotor is being controlled while the upper, with the flybar attached, is just spinning around. I can see the gyroscopic affect of keeping the upper rotor blades stable, but no influencing on the bottom rotor or cyclic controls. Anyone have a good explanation of the interaction. please.

[Fan M]

I think that the two rotors are actually connected with the rotorshaft which is also connected to the aircraft. Any input, be it some cyclic input or some input from the flybar-upper rotor assembly are adding and interacting together by the movment of the heli.

I guess that, by lessening weights of the flybar or shortening the flybar, the cyclic input gets more influence while the overall stability decreases.

Maybe one somebody can give us some further information.

:dontknow

[Rick Rotorhead]

I think Fan M has it nailed - "I guess that, by lessening weights of the flybar or shortening the flybar, the cyclic input gets more influence while the overall stability decreases".

If you visualise what happens to the top rotor when you bank the heli, the weights try to keep dead level, which pulls on the top rotor in the manner of cyclic input to counter the banking and keep the heli level. That's your stability. The bottom rotor has the cyclic control and has to fight against the self levelling top rotor. Which is does to a limited extent and the result is you get a gentle bank out of it. reducing the top weights reduces the gyroscopically controlled top rotors cyclic and allows the bottom rotor to have a greater influence on the helis banking.

I have a lot of trouble penetrating even 'almost imperceptible' breeze, even with the servos on the second hole, so I'm gonna try a slightly lighter flybar too.

[Kindling Maker]

helimech66 See what you started. Now everyone is goingt o have shortened flybars and bigger engines. I just got back to my base. As soon as I get to my hooch I an going to order the Ball bearing motor from slick zero. I have a spare flybar and I am going to cut it down and get it balenced. The onlt thing is I thing my stck motors are going to go out, they are screaming like a banshee. I do have a good stock of the Eflite motors.

[Fan M]

Right now a small fly is flying around me. Crazy little fly knows somehow more about aerodynamics and physics than we all do. Amazing. It maybe doesn't know but it's flying.
Maybe, to become good pilots we have to fly a lot like the little fly.

Just a little remark

:fly

[Kindling Maker]

well I shortened the Flybar and used the Rubbers as weights. WOW the performance was much better. Rite up until the time I slapped rotors trying to get stopped before I hit the wall at the other end of the building. I was using a lot less throttle and if I had not over controlled it it would have been great, instead it became a brick. I held a hands off hover for about 10 secs so it was stable and and easy to get there. I was at less than 1/2 throttle in a stable hover when I nozed over and gave it the go-go stick. I just got in a set of gorilla gear and the tail boom kit from Boomtown so I will put then on tonight and see how it is then, today I ordered the 180's from slickzero so we will see how it all works together.

[emag remrofni]

That is one good looking CX

[helimech66]

Sorry I havent answer kindling maker, I was on vaca, If you notice the pic I posted at the begining of this post the flybar uses cp weights but no paddles. Try 2 weights on each end. just a side line note: dont assume the # on these rotor blades are accurate. snap a set together and see if they balance on the side of a screwdriver. I found that can make a big difference. If you guys have ever seen a UH-1 helicopter it has a flybar, but It is really called a stabalizer bar. The BLADE people just didnt make this little item up to confuse us. lol this is the defintion of a stab bar.
The stabilizer bar is connected into the flight system in such a manner that the inherent inertia and gyroscopic action are induced into the rotor system to provide a measure of stability for all flight conditions. If, while hovering, the helicopter's attitude is disturbed, the bar tends to remain in its present plane. The relative movement between the bar and the mast will cause the blades to feather and return the rotor to its original plane of rotation. When the rotor disc is displaced by cyclic action, initially a portion of the cyclic movement is removed, but because of pendulum action of the helicopter, the mast is displaced. Now, because of the restraining and damping action of the dampers, the bar possesses a mast-following characteristic. The time it requires the bar to follow the mast and return all the cyclic control to the rotor is determined by damper timing. A compromise between gyroscopic action and damper timing is maintained during flight which allows the bar to provide a measure of stability, yet still affords the pilot complete control of the helicopter. I will get a video out to you guys after the 4th. :glasses2: