Trex550x: How to level swashplate and rotor head with new landing skid

[lahannsven]

Hi folks,

I just see that the new Align Trex550x is no longer horizontal with the landing skid. This is now obviously the new SAB Goblin style.

Do you level now the swashplate and rotorhead without the diagonal landing skid? I fear it get's more inprecise.

The new Trex500x will be similar.

Also your Flybarless unit needs to be exactly horizontal.
This is with the new landing skids no longer the case.


Sven

[ic-racer]

"Level" the swash is a misnomer. The swash should be perpendicular to the main shaft.

I don't think any FBL needs to be perfectly level when it boots. Stationary, but not needing to be level.

[lahannsven]

The FBL unit should be horizontal at initialisation.

In my opinion setup will no longer be precise.

Align obviously follows SAB heli division.

The new Trex500x also looks like this and will have even belt driven tail.

Sven

[learnedthehardway]

There are several helis without a perfectly horizontal stance, as a matter of fact the Chase 360 is the only one I've owned that's very close to horizontal and some like the Goblins and even the Oxy3 have a sharp angled stance.

Using a swash leveling tool or the ziptie method has worked the same for me regardless of the stance. Only thing is it's hard to check if you have 0° pitch all the way around.

I just set 0° at midstick on the blade coming off the front of the heli and the other over the boom, then rotate them 180° and set 0° with the other blade coming off the front. The motor and other parts are still level from side to side so you zero your pitch gauge on that plane instead of front to back.

Doing it that way gets everything setup perfectly fine. Leveled a couple of them to make sure I had 0° at midstick all the way around after doing it that way and it was perfect.

The stance has had no effect whatsoever on the AR7200BX, SK540 red or SK540cl I've used so far. The fbl is constantly working at every angle under the sun when someone is doing 3d, it's not a problem. The AR7200BX manual even says to lay the heli on its side to initialize it if it's windy out to keep the wind from moving it around during initialization.

Maybe a unit with self level needs to be initialized on a level surface but mine certainly do not.

[learnedthehardway]

Even if it did matter if the fbl was horizontal upon initialization for it to know where level is, if you did it on a heli that flies/lands on a raked or whatever it's called stance (lol) I imagine that would make it lean backwards during flight.

[rhodesengr]

I dont have my 550x in front of me but I don't recall the FBL mounting platform to be at the angled of the landing gear. I had no issues doing the setup. As mentioned above, you level the swash wrt the main shaft. If you use any other method, you risk add in inaccuracy. Using a trippod tool, a Lohr type snap-on tool, or even a zip tie directly references the main shaft.

[BadVad]

Could you remove the skids and tail fin and set the helicopter upright level on its frame for setup? That's what I plan to do when my 550x shows up.

[yakky]

Alex, I'll take problems that don't exist for $500.

[ic-racer]

Originally Posted by BadVad

Could you remove the skids and tail fin and set the helicopter upright level on its frame for setup? That's what I plan to do when my 550x shows up.

There is no defined reference between the swash and the frame. Swash needs to be perpendicular to the main shaft.

[tonys-heli]

I just put the rc logger on the motor or flat part of the frame perpendicular to the boom and hit zero..now its zeroed to the frame and hopefully mainshaft..then put in on the blade over the tailboom and run through fbl setup..then next part of setup is move blade perp to boom..re-set zero on the logger inline with boom on motor and do the rest of setup..for vortex any way..no need to care about mainshaft tilt or skids cause your zeroing it out.
that's how I do every heli I own. works for me..hope that helps

[gstoneberg]

Originally Posted by BadVad

Could you remove the skids and tail fin and set the helicopter upright level on its frame for setup? That's what I plan to do when my 550x shows up.

What I did is cut a piece of plywood so that it's larger than your skids. Take 3 long bolts and thread 2 in the front (one in each corner) and the other one in the center of the very back. Sit the heli on the plywood and adjust the length those bolts come through the wood until the frame is level both directions . Now you can do your setup with a level frame.

[rhodesengr]

So I took a look at my 550 tonight and the FBL stage is at -5 degrees when the skids are flat on the table. It doesn't seem to matter. I guess it just initializes out.

As far as setup goes, I have never understood why folks try all that stuff with the motor, tail boom, wasting time trying to level the frame etc. etc. The only reference that has ever mattered is the main shaft. A swash tool levels the swash to the shaft no matter how unleveled the frame is. You can set zero pitch to the main shaft also with a rod through grips.

[Crashalotjoe]

If you think about it, when flying you want the disk to be perfectly horizontal and the main shaft perfectly vertical otherwise the heli will move in the direction of the tilt. To achieve this the swash needs to be perpendicular to the main shaft. If you set the swash level to the frame it would tilted back when compared to the main shaft and the heli would constantly drift backwards. So, level the swash with a levelling tool or the zip tie method.

Most FBL's don't care how level they are when initialising (within reason), those that have self levelling functions generally check level constantly when in flight.

[Smoggie]

Originally Posted by Crashalotjoe

Most FBL's don't care how level they are when initialising (within reason), those that have self levelling functions generally check level constantly when in flight.

^^ exactly. Conventional FBL with 3 axis gyros have no way of even detecting if they are level or not. You could lay the heli on it's side or put it upside down and it wouldn't make a jot of difference. The only important thing is that it's stationary during initialisation.

Controllers 6 axis FBL controllers (3 axis gyro plus 6 axis accelerometer) detect the force of gravity, so they can tell if they are level or not, but as long as they are within about 30 degrees of level they initiate just fine.

As already noted, for levelling the swash the position of the heli is irrelevant. You could just as well level the swash with the heli on it's side.

FWIW I have a Trex 700X which has the same landing gear as the 550X and the same 5 degree nose down tilt. It's no different in setup or use to any other heli I own. I also fitted the 700X/550X landing gear to my Trex 600 Pro to give it the same nose down tilt, and that too works the same as it ever did.

[tacomaster]

Originally Posted by tonys-heli

I just put the rc logger on the motor or flat part of the frame perpendicular to the boom and hit zero..now its zeroed to the frame and hopefully mainshaft..then put in on the blade over the tailboom and run through fbl setup..then next part of setup is move blade perp to boom..re-set zero on the logger inline with boom on motor and do the rest of setup..for vortex any way..no need to care about mainshaft tilt or skids cause your zeroing it out.
that's how I do every heli I own. works for me..hope that helps

This. If you have a digital pitch gauge it doesn't matter at all. Just re-zero when checking elev and aileron. Mine was done like this and piros absolutely perfect. Also the fbl doesn't care how it is initialized. As long as it is still.

[learnedthehardway]

I have seen mention of rezeroing the pitch gauge when doing each blade but I've never had to do this when I zero it on the motor adjacent to the boom and adjust zero pitch with each blade coming off the nose of the heli and the other lined up with the boom as long as I make sure the heli doesn't shift when rotating the second blade to come off the front.

Am I missing something? Wouldn't using a different zero possibly throw off tracking or is rotating the head a waste of time and I should just set zero pitch on the other blade while it's still over the boom??

Don't know why I do it that way but always have and it always works. Just curious

[heli addiction]

I wondered the same thing when i built my 700X, i also thought it had to be level when initializing. I set 0 pitch with the heli level and then again with the 5 deg rake skids just to be sure. Its fine the swash is square with the main shaft and it fly's perfect.

[Crashalotjoe]

Originally Posted by learnedthehardway

Am I missing something? Wouldn't using a different zero possibly throw off tracking or is rotating the head a waste of time and I should just set zero pitch on the other blade while it's still over the boom??

Yes, you don't need to re-zero. Do one blade, turn the head, do the other blade without re-zeroing (you can of course do it without turning the head depending on the type/fitment of the pitch gauge). The only time you may need to re-zero is when you are checking the aileron side with the blades perpendicular to the boom but that's another subject.

[ic-racer]

Pitch is also referenced to the main shaft but not so easy to do. In that case, yes I do define a reference on the frame with a known relation to the main shaft.

All my Align helis have at least one symmetric portion of R & L frame side at the top. I do make 100% sure the sides are perpendicular to the main shaft. Then zero the pitch gauge to the top of the frame side to side and use that zero reference to set collective and aileron pitch with the blade pointing toward nose or tail.

I don't have a defined front-back frame area that is defined as perpendicular to the mainshaft; that is OK with 3GX because you set aileron and elevator to the same transmitter swash percentage. That is, with that FBL you don't ever need to set blade pitch with the blades perpendicular to the frame. Always blade forward, referenced to to top of the frame side-to-side.

[tacomaster]

Originally Posted by Crashalotjoe

Yes, you don't need to re-zero. Do one blade, turn the head, do the other blade without re-zeroing (you can of course do it without turning the head depending on the type/fitment of the pitch gauge). The only time you may need to re-zero is when you are checking the aileron side with the blades perpendicular to the boom but that's another subject.

i always check my pitch at aileron and elevator, thats how i know the swash is truely level.