View Full Version : Tail rotor problem
geerbangr
04-08-2007, 11:13 PM
I just built my new Raptor 30 V2 . The problem is , the tail rotor is not turning properly . It acts like it is slipping when you start coming up on the throttle . I understand the main rotor turns clockwise and the tail must turn counterclockwise . I thought I assembled the bird properly because when I rotate the main rotor the tail turned counterclockwise . But now that I had her fired up and see what is happening i'm wondering what I did wrong . Can you install the tail drive belt wrong ???
the tail must turn counterclockwise
When viewed from the right side of the heli it turns CCW. It's easily possible for it to go the wrong way, it's just a matter of which way you make the 90 deg twist in the belt when you hook it to the drive gear. It will work either way but CCW rotation is preferred. It's my understanding that there is less tendency of getting a "vortex ring state" going on in the tail rotor with CCW rotation.
(http://cybercom.net/~copters/aero/settling.html)
Make sure the belt is riding in the guide rollers and the tension is correct. You should only be able to push the belt about 1/4 inch. Look carefully to see that the belt is riding down in the rollers, item #11. (page 6)
Also, the pully (in the tail), item #24 has a pin to fix it to the shaft, item #14, and a grub to hold that in place, item #30. Try to turn the main rotor by hand while holding the tail rotor still and there should be no slip... you should not be able to turn it. Don't be too forcefull about this... if you forgot the pin it will easily slip and you'll be able to turn the main while holding the tail rotor still. (page 12)
BarracudaHockey
04-09-2007, 11:27 AM
With the advancing blade turning up and into the main rotor down wash it makes the tail more efficent. Though its benefits on models are debatable its the reason most full scale ones do and infact triggered a redesign of the tail on the "huey" to give it more tail rotor authority.
Make sure your tail belt is properly tensioned. Make sure the set screw that goes into the tail shaft end and holds the pin in place is locktited and tightened and make sure the belt only has 1/4 twist.
Looking down the mains should rotate clockwise, looking at the right side of the the heli the tail should turn counter clockwise (throw dirt forards if it hits the ground)