Blades have free pitch movement - normal?

[rack201]

G'day Folks

New Belt CP owner here after graduating from a Lama 3 - probably too quickly but I'm taking things easy..

I have followed various setup videos in regards to blade tracking and pitch but I note that I am able to move the rotor by hand (when powered up with motor disconnected) through quite a range of pitch without moving servo linkages/servos.

I just want to check that this is normal? Hovering though I'm barely there seems ok - lift off at 60%-70% throtlle. Nothing appears bent or broken, and I have not yet crashed it. What I assume happens is that when the head speed is at flying rpm, the air pressure on the blades forces them to zero pitch, and the servos act against that position?

Thanks

[Nitroxda]

That's what I see too when using the stock plastic parts, I ended up now installing the cnc head and tail from Esky. guess what? I still have the slops:confused:

This is my first heli, and I have been wondering the same thing.... is this normal?

I could adjust the slack to almost zero from the paddle / flybar, but the control arm would not be horizontal anymore, but in V shape when at o pitch (idle up, throttle stick middle).

[Ber60]

Hi guy's
Yes it's normal.
The slop is mostly from the servo's (and links) if you are still flying stock.
They can be moved aboud 1mm wich translate at a 1 to 2 degree's of pitch on the head. Almost everybode here on the forum are flying SG90's and many did the DTS mod to reduce the overall slop and it helps.

[rack201]

Thanks Ber60 - I will check out the mod.

I think I amm getting a lot more than 2 or 3 degrees though. This is straight out of the box, completely stock. I seem to be able to rotate the entire rotor (ie. both blades fixed) 10 or 15 degrees without changing the position of the swash plate (hence servo arms)... it feels.. 'loose' but it may be just the way its supposed to be.

I tried to explain in the following pic:

Cheers!

[another_finn]

Ah - I was wondering if you might mean that tilting action :)

Don't worry, that's normal. This is how you get most of your cyclic pitch - the flybar paddles "fly" into position to increase pitch on one side of the rotor disc while reducing it on the other. In level flight, the paddles and air pressure on the blades keep it from tilting freely.

[rack201]

Thanks a lot Mika - I knew what I was trying to describe, but could quite do so clearly ;).

Time to study up on the flybar and what it does exactly..

Thanks again!

[Ber60]

Hip Hip Hooray for the almighty picture

[rack201]

Indeed.. but I'm still a bit unsure on what effect that tilting ability has on your ability to set pitch?

[Ian 777]

Set your main blade pitch in relation to the flybar. A pitch guage fits to the leading and trailing edge of the blade, you sight it to the fly bar and then read the scale to give you your pitch.

[another_finn]

Indeed.. but I'm still a bit unsure on what effect that tilting ability has on your ability to set pitch?
You're probably thinking of collective pitch here - increasing or decreasing pitch by an equal amount on all points of the rotor disc. What the flybar system gives you is cyclic pitch - what tilts the helicopter and allows you to go places ;)

Try tilting the flybar to maximum deflection and see how the blade angle changes in relation to the helicopter. The blades do not change pitch in relation to each other or the flybar, but you now have loads of pitch on one side of the helicopter and very little on the other. That difference is what gives you cyclic roll capability.

Like Ian says, when you measure pitch you do it in relation to the flybar. That's because the flybar and blades tilt as a unit, and what you're really measuring is collective pitch. It's actually a little more complicated than that, but you'll be able to figure it out if you take a close look at what the head is actually doing when you input some cyclic on the swashplate and turn the blades slowly by hand.

[Nitroxda]

For my case it is not the cyclic movement, it's the "play" or "slack"...I hold on to the paddle / flybar keeping it still, and I could change the pitch of the main balde by 1 to 3 degree without moving the servo horn yet... I found the slop actually present in the links... say each ball link has 0.01mm play.multiply by the amount of ball link being used in the system??:shock:. and the ESky servo itself have excessive play too before you can hear the motor inside turning. I mean this heli is sooo... sensitive, I believe such a play may cause inconsistence...:confused:
I was saying these as i just came back from LHS and compare to other helis there, yes they all do have some slack, but in the minimum. I check a new TRex with plastic head, i estimate the slop is less than 1 degree on the main blade doing the same finger test, and the HS 65 servo, there is no free movement at all without involving the motor.

Hope you guys understand what I'm trying to explain here.:smokin:

[helihathnofury]

I think it is just slack in the system. Despite having upgraded servos [sg91s] and the "direct to swash" DTS mod, I still have a bit of slack. But hey, this is a pEsky CNC head, not the most precise piece of engineering around. It is also the reason many of us go for upgraded metal heads too - me the copterx head - or a trex type head. Same goes for the tail rotor system too. My slack is in what i consider to be a tight feathering shaft and dampers!!!!!!!! Roll on the copterx head!!
Welcome to the Belt forum, anyway, there's lots of great advice and help here.

:thumbup:
:cheers


Mike

[another_finn]

Hope you guys understand what I'm trying to explain here.:smokin:
Perfectly. That slop is one of the main reasons most of us are using the direct to swash mod and upgrading to Align/3DX/CopterX heads. It's not so bad on a brand new helicopter, but it starts developing fast and it keeps getting worse until you change practically everything. One degree or so is probably inevitable with so many moving parts, but three degrees can't be helping much with accurate control...

[muppetman0]

Are you using the Esky CNC head? I think that the general concensus here is that the Esky CNC head is not much better that the plastic one.

[DierWolf]

Esky Plastic and Even CNC head has alot of play in it even before it reaches the the servo... Its a combination of ball links being too small, substandard bearings not fitting perfectly on there shafts/screws etc etc.

Something you will have to live with... only way to get rid of it is going to a better head such as the Trex Headstyle or CopterX.

[Nitroxda]

But those heads (TRex n Copter X) alone cost more than my Blade CP....:roll:

Maybe I should have started learning to fly heli with a Trex 500, then I try the Belt CP again when I'm good, not the other way round:mad:...........:P

[DierWolf]

No they dont.. they cost 57 bucks

[DierWolf]

here Xheli has theirs back in stock (Trouble free direct swap without having to buy another swash which you would have to do if you got copterX head for $57)

http://www.xheli.com/esbecpalheup.html

Hardly the cost of a Belt CP.

[DierWolf]

And if you want to further the Bling and crashability of the heli you can always add this lovely 38 dollar item.

http://www.xheli.com/esky-belt-cp-upgrade-tail-rotor.html

Still with both your still under the price of a Belt CP.

[muppetman0]

But those heads (TRex n Copter X) alone cost more than my Blade CP....:roll:

You can't get Champagne for beer money ;)

[DierWolf]

Oh wait... you have a Blade CP...... geez thought Eflight was the best stuff on earth LOL never figured you would have "Slop" :)

If you paid for a Blade CP (which is overpriced as it is) you surely can pay for A better head.

Notice i capitalized the A! Guys :)

[rack201]

Thanks Folks - I had another look tonight and see the full picture. (always hard to visualise what I saw the night before while at work the day after..)

Now I am back to learning to hover the thing. Understanding that some right stick is necessary to counter the tendency from the tail rotor to drift left, but a question.. Does this stick input need to be constantly maintained throughout hover, or once airborne, it goes away?

Cheers?

[Nitroxda]

Yeah. you get what you pay for...... But I will stick to my current set up for now.
I have been reading a bunch in the RC heli for a few weeks.....
IMO, going through CNC head and tail, better 3 cyclic servos HS-55, GY401 with digital servos, which in turn needing a better BEC or ESC, and then getting a DX-6i... DTS mod..... I would rather get a whole new heli to start later.:roll:

[DierWolf]

sideways movement of the heli on take off is because of torque of the main blades and the force from the tail rotor, yes they both go away after your airborne.

Scooting around the ground is the long process of learning (radds school suckx)

[Ian 777]

More E Flight infitrators???? Mamma git me ma lynchin rope:lol: