Hurricane 550 terrible wag (or hunt)

[mlinder]

Hello guys,

I am a long time lurker on this forum, reading all I can about the Hurricane. I purchased on last year, but only recently began getting it ready to fly. My other heli is an ESKY King 2 for the backyyard. I am still a noob. I hover pretty well (except nose in), and can fly somewhat anemic FF. I got the hurricane for a more "forgiving", stable flier. Here is my setup:

CHP CF frame with S9650 servos on cyclic
Spektrum DX7 with Futaba S9254 on the tail.
Futaba GY401 Gyro
Z20 980KV motor
Align 70A ESC
14T with OK gear.
20T OWB
Stock wood blades
6s 3300mah lipo
CNC head (added)

When I first set this up, I had the stock plastic head , except the grips. It flew fine. Then I added all the remaining CNC head parts, except the swash (The one Helidirect sent me was broken). So the swash is still stock. This is where things went awry.

Now when I spool up, I get a terrible left/right wag or hunt. Probably 4-5 inches each way. I can see the gyro servo arm moving back and forth. I have tried several gain settings, but nothing is working. I guess it's the CNC parts, since the heli flew fine before they were installed, but I don't know why they would cause a problem. Anyone else have this happen?? I dread putting the stock pieces back on, especially after paying $$$ for the CNC parts. TC and PC (both normal mode) are fairly linear, except the TC is at about 70% just above mid-stick. The pitch is level at mid-stick

Can you guys offer some suggestions? I read other posts about belt tightness, but that didn't help. I'm not a good flyer yet, but I THOUGHT I was pretty good at setup - guess not!


Thanks in advance for any help you can give me.

Thanks!

Mark

[odieser]

did you upgrade the tail to the cnc grips and slider
Mark

[mlinder]

Odieser,

Thanks for your reply.

No I have not done that yet (ran out of $$$). I checked for cracks in the plastic cases, but found nothing wrong there. I also checked the bearings and they are good.


Mark

[odieser]

Okay the reason I asked is that the cnc tail from helidirect I put on gave me a lot of binding in the slider so I tought that mite be the problem here. I will keep thinking.
I don't think that changing anything on the head should effect the tail other than belt tension but you checked that already.hmmmmmmm
Mark

[Mikej]

a Couple of questions and a possible suggestion -
Did you manage to lose the wag if you turn the gain down ?
which hole on the servo arm are you using ?
How much gain are you using ?
HH or gain ?

I would be tempted to set up a pretty flat throttle curve - something like 0, 85, 90, 90, 95 and a pitch curve similar to 38, 50, 62, 80, 100 and then tweak the pitch curve so that you hover just above have stick you will have a flat throttle curve where you are hovering / flying (which brushless motors are most efficient with apparently) and you control the lift by pitch rather than motor speed.

The other thing that is usually suggested is to have the link for the tail link closer to the middle of the servo and higher gain as opposed to further out on the arm and lower gain - this will give higher resolution and more accuracy.

Good luck,
Mike.

[mlinder]

Thanks for the ideas.

I am using HH at about 78%, but it doesn't help the higher I go with it.

I'm going to try to move the link in - I think I have it out too far. I get a bit confused on the servo throw. I moved the arm out to get more throw, but, as you suggested, it probably messed up the sensitivity. What is your length from servo center to your link hole?

Many thanks for the suggestions. I really like(d) this heli early on. I hope I can undo what I did to mess it up so I can do some more uncontrolled aerobatics!

Mark

[mlinder]

Well, I moved the link closer to the servo center - A LOT better. Battery was pretty low when I tested so tomorrow afternoon I'll work on it some more. Just a little wag right now at about 65% HH gain. What is a good HH gain value to have anyway? (I know - my mileage may vary...)

I had swapped out my S9254 with a DS821 when i started having problems just to see if it was the servo, so I need to put the S9254 back in.

Mark

[michael88997]

i only fly with like 55 to 60 hh and my tail is solid... do this, take off in hh mode, flip it into rate mode and see what happens. i have a feeling somehow your tail isn't centered and its messing up the gyro, with the 401 you need to be able to hover your heli in rate mode with the tail staying straight

[mjdee14]

try upping the Throttle to 85% at midstick....you might be too low and the tail doesn't have enough speed to hold....

[istandalone]

i'd start out with 45% gain. i can fly with less then that and it holds perfect. then again, i suck too lol.

[Mikej]

Thanks for the ideas.

I am using HH at about 78%, but it doesn't help the higher I go with it.

I'm going to try to move the link in - I think I have it out too far. I get a bit confused on the servo throw. I moved the arm out to get more throw, but, as you suggested, it probably messed up the sensitivity. What is your length from servo center to your link hole?

Many thanks for the suggestions. I really like(d) this heli early on. I hope I can undo what I did to mess it up so I can do some more uncontrolled aerobatics!

Mark
Mark,

I use a small wheel on the tail servo, the ball is about 7 - 8mm from the centre of the servo.

If you have wag then raising the gain is going to make it worse not better. The way in which most people recommend setting up the tail is to keep raising the gain until the tail starts wagging and then drop it down a few notches until the wag stops.

Good luck,
Mike.

[mlinder]

Thanks to you guys my problem is solved.

After all my "tweaking" putting on the CNC stuff, CF frame, etc.it came down to what was suggested - moving the link ball closer to the servo center. Don't know how/when I moved it, but it got moved. Now it flies great, and the tail holds just fine.

I am a happy guy.

Now - it's time to conquer that "nose in" demon!!!!!

Hopefully, Iwill be able to contribute a constructive thing or two to this forum as time moves along.

Have a great weekend!

Mark

[Mikej]

Thanks to you guys my problem is solved.

After all my "tweaking" putting on the CNC stuff, CF frame, etc.it came down to what was suggested - moving the link ball closer to the servo center. Don't know how/when I moved it, but it got moved. Now it flies great, and the tail holds just fine.

I am a happy guy.

Now - it's time to conquer that "nose in" demon!!!!!

Hopefully, Iwill be able to contribute a constructive thing or two to this forum as time moves along.

Have a great weekend!

Mark

Great news Mark - well done