Raptor 50 push-pull elevator

[Maxime30]

I'm trying to figure if the stock geometry for the push-pull elevator on the Raptor 50 Titan is correct. A few months ago, there was a good article written in RC Heli Magazine about push-pull setup, and they said the control balls on the servo arms should be at the same distance from servo center as the ones on the push-pull lever. However the Raptor manual says to install the balls 10.5mm from servo center, and the balls on the push-pull elevator arms are installed much farther than 10.5mm from the center of the arm.


Can this cause binding?? I tried installing the balls at about 10.5mm from center on the elevator push-pull arm, but I had to lower elevator ATV to about 60% (not good...)


So please tell me your opinions about how I should setup this linkage....


Thank you!

[Badger50]

Hey Maxime: I don't know the exact geometry fo the 50 Titan, however, this is what I use on my Rap-90. Sorry about the pictures, I'm still learning this forum posting thing, but I think you'll get the idea.

1) On the elvator arm, the balls are 20mm from center.
2) On the servo arm they are 10.5mm from center.
3) Push rods are equal length of 110mm.

This is the stock raptor 90 setup. Works great. I run my ATV at 100%, and could go higher if I wanted to. hope this helps. :)

[Maxime30]

Thank you for the reply. I also own a Raptor 90 3D (not yet flown), and the elevator linkage is adjusted like yours. If you look at your elevator push-pull arm, you'll notice that the two arms aren't exactly diametrally opposed, they are slighlty angled in a "V" shape.


The plastic elevator push pull arm on the Titan is straight, that's why I'm wondering if the balls on the servo horn should be spaced exactly like the ones on the elevator push-pull arm to make a perfectly square (or rectangular?) linkage.


The reason I'm asking is because I'm setting this Titan helicopter for a local guy, and he is using JR 821 servos, which are known to sometime fail in a 50 size helicopter. So I want to make sure there will be no binding in his control system.

[Badger50]

Hey Maxime: If it were me, I would duplicate the setup on our Rap-90's. You have to allow enough mechanical travel on the E-arm in relation to the servo arm or else it will bind and thats why your ATV is set so low. Heck we know it works on the 90's, so I don't know why it wouldn't on the titan. Just out of curioscity, how many mm can you get from center on the E-arm?:thinking

Just thought of something, (something new for me) If you look at the push-pull collective on our 90's you'll notice that the contol balls are equadistant on both arms, and the arms are diametric as well. So I would think you could do the same for the elevator. :thumbup:

[BarracudaHockey]

The reason I'm asking is because I'm setting this Titan helicopter for a local guy, and he is using JR 821 servos, which are known to sometime fail in a 50 size helicopter. So I want to make sure there will be no binding in his control system.
JR Warns against using them in a 50, personally I'd tell him get decent servos or do it himself.

Its not binding that causes them to fail its vibration. Oh yea, and there's about a dozen threads about them shearing off and dying in flight.

[kas4j]

In the image below, the circles with the yellow dots is your servo, the circle with the purple dots is your elevator control arm. the yellow dots should be equally space from the center of the servo and the purple dots should be equally space from the center of the arm. they do not have to be egually with each other ( elevator arm the same as sevo) the image on bottom will give less throw and the one on top will give you more throw. the push rods (green) do have to be the same length. My titan is set to the image on bottom. The titan manual shows the balls in the elevator arm as being the furthest hole out and the servo at 10.5 mm . i hope this helps :)

[Raptorman37]

the shearing is caused by (A) Using them in a 50 and (B) using threadlock on the servo horn screw, the gears are all hard plastic, we all know what happens when you add threadlock to the wrong type of plastic. I flew DS821's in my raptor until recently, i now run the Futaba BLS 451's.