BUBBA633

Can someone please send me pictures of your tailrotors with with clear positions of the blade grip positions? Thanks[&o][&o][&o][&o][&o]

tippy

Just a guess ... because I've done this too ...

If you've rebuilt your t/r system, ensure that the blade grip links are leading (see photo) the blades instead of trailing the blades.
Leading and trailing is in reference to the direction of rotation of the t/r.

During a rebuild (before the links are connected and blades installed), the blade grips can rotate 360°. You can inadvertantly connect the slider links to the grip links where the links are trailing the grip instead of leading.

Since most blade grip links have a built in right YAW offset (to counter torque at hover), reversing the grips (trailing config) will cause the offset to be more left YAW, adding to torque instead of countering it. This will cause your heli to YAW left and practically no amount of TX trim will correct for this and probably no amount of heli linkage adjustment will either.

So, ensure the grip links are leading the blades.

BAAMflyer

I just recently pyrchased a falcon 3d heli but I have been flying nitro heli,s for several years . the info shown in the picture was very good and applies to both electric electric and nitro heli,s. If you still are having trouble after. checking that , you can let me know and I will walk you through a set up. ,

BUBBA633

Thanks for sending me the mail and picture of "defining the leading edge and trailing edge". I have see this one many post and it was very confusing to me however I feel this is where my problem lies! I'm still somewhat confused but you picture is helping to clear the fog in my head!!! Can you pleae send me more pictures at different angles, of how the blade grips should be? Thanks so much !

Bubba

BUBBA633

Thanks BAAM I'll let you know!

tippy

I don't have a falcon 3d ... the image came from the internet ... however ... the principals are the same.

Not only do you need to ensure that the blades' leading edges are correct but you also have to ensure the blade GRIP leading edges are correct. This is very easy to install backwards during a re-assembly if you're not paying attention.

Here's the same image with a little more info:

BUBBA633

Heres pictures of mine. Please tell me this is wrong!!!

tippy

Yikes ... where to start ? !!!!!
OK ... I've marked up one of your images ( and keep the image I posted handy).

First the images and then the analysis afterwards ...



First, referencing the image I posted, I assume that the t/r system is a reverse rotating (ie bottom blade moves foreward, top blade moves aft). I'm also going to assume that your heli (should) work the same way.
With that said ... let's dig in ...

Let's reference the image you posted ( the one I marked up).

First ... the top blade. The top blade should rotate aft ... so the leading edge should be aft. Yours is facing forward.
Your first instict may be to remove the blade and turn it around .... but don't ... following me on this. The blade is in the grip correctly ... it is the grip that is turned 180°.
So for now ... disconnect the ball link from the slider link ... might as well do both blade grips.

You're looking at the image ... right?
Now ... the bottom blade. It "appears" that the blade is aimed correctly (leading edge facing forward for the bottom blade) however the link is on the trailing side of the blade ... the grip on the bottom blade is also backwards.

So, you've got both ball links disconnected and removed the bottom blade ... right?

Now, rotate each grip (that's the grip, not the rotor) so that the ball link is leading the blade (ie top grip ball link should be pointed aft and bottom grip ball link pointed forward). You can only do this with both ball links disconnected. It appears from the image I originally posted, the blade grip screw head should be facing outboard (away from the boom). Did you notice that your screw heads are facing your boom???

Now, reconnect the slider links to the grip ball links ... making sure the ball links are LEADING the grip and the grip screw heads are outboard (away from boom) (refer to first image).
Now reinstall the bottom blade ...

You should now be configured like the first image ... screw heads outboard, ball links LEADING the grip, and the blade leading edges are aimed correctly (top blade facing aft, bottom blade facing forward).

Of course, I would suspect that you will need to retrim/adjust everything.

Good Luck.

Cambo

My Feedback: (2)

LOL, bubba that is definatley your problem. That tail is going to do all sorts of crazy things. Get those blades/grips put on correctley

BUBBA633

Tippy,

Thanks a bunch for sending me the illustration and the information! I'll try it today to see if I can get it to work. The reason I say try it is because I'm still confused about the the trailing vs the leading edge. Because when I look at mine against your picture, they both look the same to me. When you say aft, do you mean after? If I still cant fix it could I send it to you so you can do it for me?

BUBBA633

Thanks Cambo!

tippy

Aft = to the rear, to the back of the heli, the tail end. Sorry for the Navy lingo.
Foreward = to the front, to the nose of the heli.

The term "leading edge" refers to the part that passes through an air mass first (leading). EX: the front bumper of a car would be the leading edge of the car and the rear bumper would be the trailing edge (assuming you're driving forward). The same thing applies to the tail rotor blade. The dull edge of the blade (green part in the images) is the leading edge of the blade. It should pass through the air mass first (assuming correct rotor rotation).
The sharp edge of the blade (red in the images) is the trailing edge. It's the last thing (trailing) that passes through the same air mass.
If installed backwards in the grip ... the trailing edge of the blade becomes the leading edge (rotation-wise) which has some nasty aerodynamic results.

The grips also have a leading and trailing edge (or "orientation" if you prefer). It's "orientation" is due to the pitch offset built into the ball link. In a "leading edge" config/orientation, the pitch offset induced is what you need to counter the torque generated at hover. With all things being properly adjusted, you should be able to have 0 trim at the TX and hold a fairly stable YAW.

If the ball link is in the trailing config/orientation, some of that offset is removed (adds to left YAW tendency) so when you set your heli up by the book, it will want to YAW nose left.

So when I say the ball link should "lead" the blade ... the ball link (for that grip/blade) should pass through the air mass before (leading) the blade does (for that same grip/blade).

So take a look at the "correct" config image again ... remembering that leading and trailing is in reference to the direction the rotor is spinning (top blade moves aft, bottom blade moves foreward).

Notice how your green and red edges do not match the green and red edges of the "correct" image ... relative to the direction of the tail rotor rotation. Notice in your image, the top blade's trailing (sharp) edge is the first thing to pass through the air mass?? That's not right. You have the trailing edge OF THE BLADE acting as a leading edge of the rotation ... this causes all sorts of aerodynamic issues.
The leading edge of the blades (dull edge) should be the leading edge of rotation.

Notice how both of your blade grip balls are trailing the blades ... again ... not right. In the "correct" image, the ball links are leading the blade.

Again ... leading and trailing refers to the direction of rotation.
Look at the images again ... and refer to my last post to correct your issues.

tippy

I think once you get your head around the terminology and your problem ... you'll probably blush at how simple it is to fix


Stick with it ... you are on the verge of a great discovery ... RC heli repair !!!! Second most exciting thing to flying one!!!

BUBBA633

Thanks Tippy!

I'll let you know how I make out.

BUBBA633

Tippy, is this now correct? I straightened out everything as you stated and I think its just like your picture....But IT STILL SPINS!!!! I'm really ready to throw this piece

tippy

The last three of the images seems to be correct.

Remember my post where I said " ... Of course, I would suspect that you will need to retrim/adjust everything ..."

That's what I was talking about. Once you have everything assembled (correctly), you have to make adjustments ... especially since your last adjustments was in an attempt to get a messed up tail rotor to work. Obviously, those settings are NOT going to magically work for you now.

First ... in order to set up the heli ... you need to have your gyro in RATE (Normal) mode.

Secondly, ensure your TX has the rudder trim set to 0 (centered) and ensure that the t/r servo arm is at 90° to the linkage.

Try to resist the urge to adjust the TX trim ... for now. You need to get the trim adjusted at the heli first ... or at least in the ball park.

Now ... the big question ... which way does your heli want to YAW with everything centered ... Nose left or nose right???

If it wants to YAW nose left (tail right), then adjusted the servo to tail rotor linkage (the linkage that runs from the t/r servo arm to the slider bell crank) to give more nose right pitch on the tail rotor.
I quick rule of thumb is the tail goes where the t/r leading is pointing ... so to get more nose right (tail left), adjust the linkage so that it angles more to the left (of the heli).

Of course, if the heli wants to turn right (tail left) all the time, then you would adjust the pitch angle more to the right of the heli.

In order to change the length of the t/r servo to tail rotor linkage, you will have to disconnect one end or the other or both and rotate the link ends ... essentially making the linkage longer or shorter as required.

Depending on the type of servo ... you may need to set the travel limits again since you have a brand new setup.

This may take some time to finally get things right ... so be patient.

Also, you want to ensure your headspeed is correct/sufficient. The t/r RPM is a certain ratio higher than the main rotor RPM. If your main rotor RPM is too low ... then your t/r RPM will be to low too. Your tail rotor will loose authority if the RPM is too low.

Assuming your RPM is correct or sufficient ... the linkage adjustments should work.

AZBIRD9

I just received my alum upgrades from the manufacturer and there isn't any intstructions or cut-sheets. Has anyone had the pleasure of upgrading this heli? any links that I might visit to get the info needed?
Any help would be greatly appreciated!!!!!!