Wolfpackin

In order to get my Blade 400 to have a fairly stable hover I needed to add 6 clicks, to the right, on the aileron trim tab.
I now want to adjust the swashplate to the right, mechanically, so I can get the tab back to center.

What linkage or linkages do I need to adjust to accomplish this?

So many linkages to choose from...so little knowledge.

Thanks in advance.

Torquestar

Just came back from my first successful battery pack on my Blade 400 (after lots of time on Realflight G4). This is my first "real" Heli, and it was a blast. I noticed I've got a few notches of trim to work out as well.

The first for you, though, is the aileron trim. The servo on the right side that pulls the swashplate up/down controls aileron roll to the right. If you've got right trim, that means the swashplate is too high on the right side. It has to come down a bit. Probably the easiest thing to do is remove the ball link from the servo arm and turn the ball link on the threaded rod one turn to shorten the overall length of the rod/link to the right side of the swashplate. Then when you put it back on, you'll have to pull the swashplate a little bit down on the right side so the screw can re-attach to the servo arm. Remove the trim in the TX and try flying again. If you still need trim, try another turn. If it's extremely out of whack, you can take the servo arm off the servo spline (outer gear on the right side servo) and put it downward to the next spline (again, which pulls the swashplate down on the right). Then screw it back in.

The servo arm method is pretty coarse, so moving it to a different spline is a big change usually. Screwing the ball links in/out is a smaller change. You'll have to determine how far out of whack it is and use the best method. You can also use half-turns on the ball links, but you have to remove the ball from the link and push it back in from the other side.

I'm sure someone will chime in if I missed something, and maybe even correct me if I'm wrong. Although I only have a couple weeks experience in RC Helis, I have a mechanical and electrical engineering background, so I'm hoping I'm right.

soloboss

I don't know if your heli moves just one servo to tilt right aileron, or if it moves more than one. If you remove the canopy and slide the trim tab fully both directions you will see what each servo does. Then center the trim, look at the servo that was moving carefully while moving the right aileron trim five clicks. You will get a good idea which servo moves and how much it moves.
I had to move my trim about 5 clicks right and that was SEVEN turns of the link!. As long as you count your turns, you can always put it back. I know there's a big difference between fp and cp, but servos don't know that. If you don't tell your servo, maybe it won't notice it's being messed with.

Do you suppose that will work? If I'm way off base someone will tell you.

Have a good day!
Soloboss

Wolfpackin

Solo,

Aileron movement of the swashplate is done with the use of the two side servos.
It is a push/pull setup.
So for right aileron input or trim the right side servo pulls down and the left side pushes up.

So, I think I need to lengthen the left side, shorten the right side or a combination of both.
I'm liking the combination plan.
But, my main concern is how, or if, this effects the mixing with the elevator servo or the combined motion of all servos when delivering pitch.

Well looky here..almost sounds like I know what I'm talking about.

soloboss

uh oh. I'm in over my head. And I'm gonna get a collective pitch heli one of these days. I suppose I need to learn this stuff.
Hmmm. I must ponder. Oh the other hand, you do sound like you know what you're looking for.

Soloboss

Wolfpackin

Would ya hurry up already.
I could use a little help over here.

Or at least something that puts a smile on my face...while I'm pulling my hair out.

Actually it's going well so far, I just don't understand why.

EPHeliGuy

I just went through a replacement of all servos. Getting everything lined up was a major task. Especially, leveling the swashplate. The front servor is the elevator. You can leave that one alone. However, you will have to change both, the pitch and aileron links in order to keep things level.

Which links to change? The ones connected to the swashplate, not the ones connected to the servo arms or right angles. The reason is that you want to keep the linkage as square as possible at mid throttle. That is your guide. It took me more than one try to get it right.

Hope that helps!

Wolfpackin

Now I'm confused.

So am I adjusting the pushrods that go from the servo arms to the swashplate?
Are you saying to adjust the linkage at the top (where it connects to the swash) and to adjust both, one shorter and one longer as I stated above?

A picture would be great, if you can.

EPHeliGuy

Red arrow is pointing to link to adjust. You might have to adjust both to get the swash level, one on each side. Not the front link for the elevator.

Another thought is, depending on the radio you are using, you could adjust the sub-trim, which means there is no mechanical adjustment, and your normal trim would still be centered.

Wolfpackin

EP,

Thanks. We are talking about the same pushrod and you were just saying to adjust the upper linkage as opposed to the lower near the servo arm. I'm not sure why that would make a difference but OK.

Will adjusting this linkage and/or the one on the other side effect the collective movement of all three servos for pitch?
or
Can I level the swashplate by adjusting the two side pushrods without having to worry about upsetting the other pushrods on the head?

Thanks again.

evdreamer

It might affect your pitch on the blades. I would double check that. It shouldn't affect the pitch movement of the servos. But if one servo moves less or more than the others that will affect it. I unplug the motor then put it into throttle up. Then see how the servos move in the center and at full and negative pitch. The servos will tend to make the swash uneven at full negative and positve pitch. To fix that adjust the travel of the servo that is farthest away from the others in the transmitter, so the swash is level in all three positions. That can make it fly better.

tande

My Feedback: (48)

Try this---

http://video.helifreak.com/?subpath=...CPM_Part_1.wmv

& this---

http://video.helifreak.com/?subpath=...CPM_Part_2.wmv

Wolfpackin

tande,

Thanks, I have looked at them but only once.
A lot of it went over my head.
I do need to watch them again.

EPHeliGuy

Wolf, the reason I suggested the pushrods near the swash is because at mid throttle stick you want your servo arms and linkage to be square. By adjusting the pushrod at the swash, you're keeping the linkage square.

Since you're only adjusting the pushrods to affect the levelness of the swash you will not affect the collective. If you were to adjust all three then you would adjust the collective. Anyway, all you're trying to do is get the thing level, without using the trim. And the trim did not affect the collective.

Hope that helps!