Head Options

[xptical]

I'm looking at buying a head from RC-Tek. They sell one head that is basically identical to the TREX 450 head. The other 450-compatible head uses an "overslung" flybar.


What are the advantages/disadvantages of over/under slung flybars?

Has anyone used the RC-Tek heads before?

[eightythree]

ive got a diablo waiting for parts.. so havnt flown it yet. it supposed to have a faster cyclic response from what ive read. also with the "g head" you can obtain 14 degrees of pitch.. which isnt very practical for such a small heli but i cant get over 11 on my trex.. how do you guys get 12-13 degrees of pitch anyways..?

[xptical]

I'll probably set the head for +/- 12 at points 1 and 5 and then set points 2 and 4 to about +/- 5 or so. Give a bit of manual expo on the pitch channel.

[eightythree]

im running a dx6.. theres not much options i can use and only 3 point pitch/throttle curves. i also have still not yet figured out how to setup my pitch range properly.. right now im +/- 11 and im -1 degree at mid stick and the washout is just barley hitting and the swash doesnt have much room to the collar. whats the deal?! ive tried for hours moving links to get this right and im concluding to think that its something im my radio.. sorry to hijack your thread, i figured since we are on the topic is all.

[xptical]

When I talk about the SWASH menu, I'm not talking about pitch curves.

There should be a CCPM menu for programming the movement limits for pitch, aileron, and elevator. Higher percentage means more movement. Watch the two CCPM setup videos again for details.

Since you are +/-11 and -1 at center, you have two options.

The correct thing would be to lower the swash-to-servo links one turn and lengthen the swash-to-mixer links by 2 turns.

The *easy* way would be to set pitch curve point 2 to about +5.


In the end, both have the same net effect. But using the computer to mix out unbalanced pitch will cause problems when you do 3D flying.

[eightythree]

sorry i must have misread your post.. ive tried this over and over with no outcome still. i dont have 5 points to mess with the curve and i wouldnt like doing it like that since i am getting into 3d. ill go back to it and try adjusting links again.
thanks xptical.

[eightythree]

id hate to keep coming back to your thread but this is just bugging me.. on my lunch break i took your advice and adjusted links as you stated. im now 0 at mid stick, 12 positive, and 10 negative.. i really think its my radio. in normal mode at mid stick switching to hold or idle up the collective moves up.. i think its a fault in the radio.. you can actually see more movement up on the servos arms rather than down (from mid stick). i think ill try a different receiver.

[xptical]

Some radios have a setting for throttle and pitch "volume". My HiTec radio has "volume" tabs on the side.

Scan your manual for curve plots. If you see one that looks kinda like an expo cure (but not quite) then figure out how to disable that.

Also, get a protractor and a spare servo. Screw the protractor onto the servo arm and then check to see if you are, in fact, getting too much movement in one direction.

[Finless]

I have built a flown a Diablo. Good quality so you wont go wrong there. Expect a review / overview video soon.
As to the benefits of the over slung flybar over under slung, well I did not notice any better performance than my Trex. They did set this up with good mixing as a Raptor head is usually slower but this is because the mixing of hiller input. The RC-Tek head does not suffer this problem which is inherent in usualy all Raptor head copies.
So it does have speed like the Trex head and again has good build quality.

Bob

[eightythree]

i wasnt expecting to notice any difference in flight compared to the rex after getting my diablo setup. i just wanted another heli.. :mrgreen:

as for me thinking my radio is faulty, its not.. i think im just missing something very obvious in setting up the head. i feel like such a noobie.. but then again ive only been working on/flying the rex for 3 months. ive come to the point of frustration where i need to get someone to help me set it up while i watch and listen..

[BlackTitanium]

Originally Posted by eightythree

id hate to keep coming back to your thread but this is just bugging me.. on my lunch break i took your advice and adjusted links as you stated. im now 0 at mid stick, 12 positive, and 10 negative.. i really think its my radio. in normal mode at mid stick switching to hold or idle up the collective moves up.. i think its a fault in the radio.. you can actually see more movement up on the servos arms rather than down (from mid stick). i think ill try a different receiver.

It's not your radio. You just have not found that sweet spot in the adjustment of the linkages in your head.

The tool that you need, to take the guess work out of finding that sweet spot, was discussed here:

http://www.helifreak.com/viewtopic.p...=swash+leveler

[wiz310]

I had the same problem. Have a look at your swash and see if the servo balls are in the same plane a the mixing balls. Mine were actually 5mm higher (servo balls) than the mixing balls. It was the half metal and half plastic swash. I bought another bag of links and made longer links for the servo to swash. all the problems were solved after that.

[eightythree]

thanks for the link to the discussion on the tool Black.
i knew there was something out to to help a noober.. ill have to pm him. in the meanwhile, i think i will just fly her the way she is.. thanks guys.

[arclite5]

Weird that you didn't notice a difference in flight Bob.

Immediately myself and an exceptional 3D pilot friend of mine noticed that the roll rate is much faster than the normal Rex head setup. Theoretically makes sense since the center of gravity is much closer to the rotor disc on the overslung/upper motor mount setup. Have you gotten to 3D it yet?

I tried running mine with +/- 13.5 degrees of pitch and in most cases the tail couldn't keep up with the torque casued by it and would kick out. I don't reccomend going higher than 12.5.