tail set up

[RichL]

Hi Nick,
If you are trying to get 0 degrees on the tail rotor and also keep the arm at 90 degrees then i don't think it is possible. You will have to set it so there is offset in the bellcrank if you are setting it at 0 degrees.

You will be better off achieving this by adjusting both ends of the long tail on troll pushrod so that you maintain a sufficient ammount of threaded rod in the ball links.


Hope this helps,
Ross

Ross, I agree.  The 5 degrees of pitch is built mechanically into the helicopter to compensate for rotor head torque.  I don't think it is possible to achieve 90 degrees and 0 pitch.  I can't understand how 5 degrees would negatively affect the FBL unit.  Not having 5 degrees of pitch on the tail would mean that the tail servo would constantly be compensating for rotor torque. I have always built in 5 degrees of pitch as this has always been the standard when setting up a tail gyro in rate mode.  No matter what happens head rotor torque has to be compensated for I would rather to it mechanically and have a truer flying machine.

Rich
 

[nick.m]

hi rich ,,yes i totaly agree with you but the fbl system wants 0 degrees as it does the compensating for you according to set up,,on the bench when i give the heili +or -pitch you can also see the tail moving,,,but setting the n5c tail to zero means the tail slider arm is far from 90,not much movement one way and lots the other way

[RichL]

hi rich ,,yes i totaly agree with you but the fbl system wants 0 degrees as it does the compensating for you according to set up,,on the bench when i give the heili +or -pitch you can also see the tail moving,,,but setting the n5c tail to zero means the tail slider arm is far from 90,not much movement one way and lots the other way

Hello Nick, I understand that is what your FBL wants to see but, the servo still has to do the work.  I have a hard time believing that your FBL would actually be affected by having 5 degrees of pitch built in.  I have never used your FBL unit so I honestly don't know for sure.  I'm sure that is the same reason why Matt and Ross gave the advise they did because they don't have experience with it either.  At this point it seems you have two options.  One, try it with 5 degrees of pitch (I seriously doubt it will be a problem). Two, get the manufacture on the phone and ask them what to do.  I would be really surprised if someone else had not already asked this question.  My question would be this " I have a helicopter that has 5 degrees of pitch built into the tail for rotor head torque compensation.  I can't remove the compensation,  will your FBL unit function properly with 5 degrees of pitch built in?"  If the answer is yes (which I bet it will be), great then please let us know so that we may help others that ask this question.  If the answer is no, my question would be how can I return this product?


Rich

[nick.m]

well just got off the phone to them and they said it doesnt really matter if you tell the sk540 its at zero and it isnt,,he sid to try and get it between the 2

[RichL]

well just got off the phone to them and they said it doesnt really matter if you tell the sk540 its at zero and it isnt,,he sid to try and get it between the 2

Nick, I happy you worked it out.  I didn't think it would make any difference.

Rich

[nick.m]

well just had a play with the tail settings and decided to try with the zero degrees pitch as it asks for and i still get 98% or the required travel on the side i was worried about,,so now im not sure weather i should try it like this or move it back to the 5 degrees offset

[RichL]

Nick, if it were mine I would put the offset back in.  As discussed before the rotor torque compensation has to be accounted for, I would rather it be accomplished mechanically and save the servo some work but, ultimately the decision is yours.  I equate this to people using trim to correct the swash not being properly leveled on a fly-bar helicopter.  Why use trim to correct a problem that can be corrected mechanically. 

Rich

[nick.m]

ok rich i understand your point and will sleep on it lol,,got to wait a few days for my new exhaust any how so wont be flying it untill next weekend any how

[RichL]

Nick, happy to help. 

Rich

[Ross Lawton]

Great to hear you got a response back from skookum on this, keep us updated on how things go.

Cheers,
Ross

[nick.m]

well at first i flew the heli as skookum recomended with 0 degrees pitch on the tail,,the tail did have a small twitch which im sure i could of dialed out but as i was breaking the motor in i wasnt to bothered and the heli flew fine,,so this weekend i set the tail back to its 5 degree offset,,now the tail was much better behaved and no twitch at all,,the only problem seems to be as the heli is on the floor as i increse throttle when the governor kicks in the tail kicks nearly a quarter circle to the right and then comes back to where it was