Mechanical binding

[ferincr]

Hi, I was looking at a video at Team-Raptor.net about how to set the linkages on the Raptor 90 and it shows how to check that there isn't any mechanical binding, but it doesn't tell you the way to solve it if there is any (you can figure out now that I do have that problem).
I tried a search here to see if I could find any threads about it without any luck.
What should I do about this? Reduce the ATV on both aileron and elevator until everything is smooth? Or there is some other way to deal with it? (like messing around with the link lengths).
Thanks,

[vera]

You mentioned aileron/elevator so I'm guessing the binding is related to the swashplate. The swashplate can tilt just so far, of course, and you need to make sure the servo isn't trying to drive it farther than that. Apply left/right aileron and adjust ATV to prevent binding. Apply up/down elevator and adjust ATV to prevent binding. But even with this, if you put the TX stick in a corner there will be binding. For a heli, the cyclic stick should move in a circle because the range of cyclic tilt is circular. But the TX is meant for airplanes also, and so the stick moves within a square area. So it's possible to ask the swashplate to tilt farther than it can go when you put the cyclic anywhere outside a circular area. There are 2 things you can do about this. One is to further reduce the ATV so that when you put the TX stick in a corner you don't bind. This will reduce the left/right and up/down to 70% of max, and you will have 100% in the corners. That's good enough for just flying around but you may want more for acrobatics. The other fix is to buy a "cyclic ring" and put it over the cyclic stick to limit the area of operation to a circle. If you use the cyclic ring you can set the ATV to give max tilt for left/right and up/down and the ring will keep you out of the "no man's land".

For a viz-aid draw a circle and draw a box around the outside of the circle, touching the circle. The center of the circle represents a level swash. Anywhere else in the circle represents a tilt of the swash in that direction. When you move the stick to the full right, for example, you're at the right edge of the circle and that's as far as the swash can tilt to the right. If you move the stick straight up from there you begin to venture outside the circle, and at this point there will be binding. The TX will allow you to put the stick anywhere within the box, but you have to stay within the circle to prevent binding. Either use the cyclic ring or reduce the ATV so that there is no binding in the corners.

Be sure to fix that binding problem because mashing the swash against the drive shaft puts drag on the motor and you might burn up a servo or pop a link off or bend a rod if the servo is strong enough.

[alexander]

Hi ferincr,


Because you have asked about ATVs then I assume you are a newer modeler, and if so you really should be setting the machine up for less than full travel 3-D. If this is the case then you may receive advice better suited to your situation.
I just don't want to see you prematurely smack your nice helicopter into the ground from an overly sensitive (full throw) set-up.

Reduce roll and fore/aft (aileron/elevator) ATV to remove all binding and use the recommended collective blade pitch angles relevent to your flying style (you can use the collective ATV or pitch curve for this). If I sized up the situation incorrectly please forgive me, no insult intended.

Stephen

[ferincr]

alexander,
Thanks for worrying about my heli, it's always nice to see other people taking care of you and I think that is one thing I like from this hobby.
I don't take it as an insult, and if it makes you feel better, I do consider myself a newbie. I have a Raptor 60 that I can roll and flip, I got this 90 as a step forward to be able to do more 3D that is why I wanted to get 100% out of it, but may be it's a good idea to set it up a bit more mellow at least until the engine is broken in and get the feeling of it before planting it in one of the craters I made with the 60 :mrgreen:
Thanks,

[alexander]

You're likely fine to go for high throw. New to me is someone earlier to your stage. The machine is pretty laid back at lower rpms even with lots of throw for engine break-in. Craters, I know them very well! :wink:

Stephen

[ferincr]

I think I'd go with a cyclic ring anyways (just to be sure).
I put D/R on AIL and ELEV so if it is too wild I van flip it and get a more mellow machine, at least for the test flight.
I have set up the gov. for 1450rpm for hover and 1850 in idle up, hopefully I'll avoid the wobble that the manual states that happens around 1600rpm :dontknow I guess I'll find out this week end :WOW :BSS