Maiden went well, cannot get tail to lock in.

[S76 Mech]

Hello everyone.

Well, I got to maiden my new N5C today and it went pretty good.  Aside from tail holding issues it seems like its going to be a ripper.  I am running an OS55hz / Powerboost pipe.  30% CP and the motor was and is running pretty good.  Its been a few years since I flew anything with a tail belt so I am forgetting what they used to feel like.  I setup my tail  so my tail slider was mechanically nuetral when I rigged my tail control rods.  I do have the tailshaft out of the tailbox 4mm or whatever the book said.  I'm not really sure if my belt tension is too tight or not.  Lost the feel on that stuff.  Tx gain is around 72% on the DX7 which results in a G light on the MB. Rail tailblades.

Anyways, todays maiden went well.  Motor sounds good.  In a hover the tail wags.  I played around with the tuning to make sure it wasn't that but that didn't help.  In Idle 1 its still there.  Did some slow 3d, flips, tumbles, slow tictocs.  The tail felt mushy.  Definately kicked when sudden pitch changes.  Idle 2 was slightly better but not great.  Still wagged but less.  Put the machine into an inverted hurricane and the tail wagged back and forth the whole time.  I landed and changed gain values in my Tx a few more times and the heli still flew the same.  Not better or worse. 

Any ideas?
Thx Rick

[Ross Lawton]

Hi Rick,

I have not had much experience with the BeastX but i am planning on getting one and converting my current N5 Flybarred so i can gain some expereince with it. It sounds like this could be a setup issue or a parameter in the BX that requires a tweek but i will see if i can help you check all the mechanical items first.

I generally set my tail pushrod up with the Servo at Nuetral and also the tail bellcrank at neutral, i set the rod length so both of these remain at neutral. Then i set the pushrod from the bellcrank to the bellcrank at the tail gearbox end, with this i set the arm at the gearbox end so that the arm with the control ball on is at 90 degree's to the boom, this should give you sufficient offset in the blades for pre-torque.

I am at work at the moment but i will get a picture when i am at home later.

With belt tension it is a little hard to explain but what i generally go for is for the belt to be tight but also smooth if that makes sense, if the belt is too tight it will feel as though there is alot of friction when you rotate the head. Also check to make sure the main belt pulley assembly is secured as if it is loose it can cause a kick in the tail.

Also check to make sure the bolt that secures the Belt Tension Roller on the upper part of the tail gearbox is not over tightened, this should be loose enough for the roller to run smooth.

Hope this helps
Cheers!
Ross

[Brandon Bartolomucci]

Hey buddy,

For belt tension you first want to make sure your boom at the frame end is even with the clamp/bracket. You don't want it to fall short of the edge and you definitely do NOT want it extended past the clamp. You will always adjust the tension from the tail box end. First you'll want to loosen the tail box clamps enough that you can move it with some force but not enough that it goes back when you put pressure on the belt. Then take a small and non-sharp object and push from underneath the tail box on the belt. You want ~2mm of deflection toward the distance between both sides of the belt. Once this is achieved tighten that tail box down!

As far as your BeastX and tail is concerned, up the gain percentage until it holds. I have mine at 92% and it is on the actual gyro switch/channel so I am not using travel percentage or end points to adjust the gain.

If you get to a point where you have a slow oscillating wag back and forth then that means the gain in the BeastX setting is too high, it does NOT mean your transmitter gain is too high. Just keep in mind the BeastX manual, as you go UP in the menu of the Beast, you adjust your transmitter gain down. As you adjust your transmitter gain UP, you should work your Beast down. It gets kind of annoying but eventually you'll find a sweet spot and for me that was setting the Beast to low and having my transmitter at 92%.


Regards,
Brandon Bartolomucci
Sent from my iPhone

[S76 Mech]

Thx guys.
Brandon, i have my tail belt tensioned up as you described. It sticks out of the fwd boom clamp about 2mm.

As far as the gain, i had both the tx gain(in gyro sense menu) and beast gain high so i will try it low/high like u described. Also, what light and letter gain is on your beastx? Mine is G.

Thx

[Brandon Bartolomucci]

As far as what letter, I cannot tell you because I never paid attention. I'd adjust then take it in the air again and see how she did.

Also, for clarification on the tail, the boom should not be sticking out of the frame side clamps by 2mm, it should be dead even with the clamp in the frame. The 2mm deflection is how much the belt should move when you push on it while tensioned.


Regards,
Brandon Bartolomucci
Sent from my iPhone

[drdispatch]

90 up the arm - I think the slider being neutral may put your offset pitch wrong - not sure.

I had a huge tail issue, turned out I didnt notice the manual showing the grips backwards and sure enough I had mine on backwards.  That made the built in offset go with the torque.  fixing that and making sure I was 90 front to back made my tail pretty awesome.

[Hendo67]

I had my tail also originally built wrong. No bad tendencies, but I was at the limits of adjustment on the front rod. Nothing lined up as it should have, but somehow it worked. Now that I flipped the control to the correct side, the mechanical set up fell into place.
I am also running the beast, and have my gain up there too. My % on a DX 8 gain channel is 93. Im in the M-N range on the lights.
You didn't mention what mounting tape you were using. The gray 3M is what everyone is having good luck with. I only needed a single layer on mine, but some other nitro guys say 2 layers (if you have some vibe issues).
Here is a great tuning article for the Beast. http://www.helifreak.com/showthread.php?t=279967. Very thorough and clears up some misconceptions about what does what. 

[S76 Mech]

Ok fellas.

Flew the N5c yesterday and the tail is still not locked in. Its frustrating the hell out me.  I 90'd up everything back to the slider. Have the correct offset. Lowered the tail lock to (low) on the MB. Played with the tx gyro gain until i got wag during backwards flight (93%). Tkurned it Backed it down to (90%) and it didnt wag. But, it blew out on me twice during backwards inverted hurricanes. Mechanically everything seems fine. Belt tension is good. No slop in the drivetrain.

What distance are you fellas running the ball out from the center screw on your tail servo?

Thx
Rick

[Chris Sexton]

Not sure if you have been asked this already, but did you double check your tail control travel limits? I was having issues with my blowing out on moves that required a lot of right rudder, IE funnels and such, and it turned out to be that I was being too conservative with the right rudder limit. I don't have a N5c, but on the belt E6/7 you can't use all of the right travel or it will stall the tail. I wasn't letting the tail travel far enough right to compensate for hard moves.

Worth a shot.

[JeepCJ]

My tail was a little mushy at first. I went with a longer arm on the tail servo, and it made a big difference.
  I left the beastx settings at defaults, and set the gain just below where wagging started in tail down funnels, and fast
Backwards.  The tail whipped a little on piro tail slides, so I raised the heading hold setting on the beastx. Very consistent then.  Last was the tail dynamics pot, just so there was very little kickback on hard stops.  Tail now feels locked in for me. My gain (I use atv's on channel 5). Is set at 56, with no drift in hovering in rate mode.

Bob

[flyalan]

+1 on lengthening the servo arm. Had that issue on. Tarot unit I had tried on a 450.  Lengthening the arm solved it. 



Alan Butler

Sent from my IPAD using Tapatalk HD

[S76 Mech]

Ok guys will do on the longer horn distance. Will report back.

Thx homies!

[Amy Botos]

I asked Matt...... 16mm from center is the spot.

Some other tips -
Check your thrust bearings for correct order + grease.
Disconnect your servo and move to tail pushrod manually to make sure it is smooth.
Size all ball links for smooth operation

Amy