Twinstar Geometry
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Twinstar Geometry
Good Day. I have also posted this in the Beginners Forum for comments or other possible fixes. When I was setting up the Aileron servo on my Twinstar, I came across this problem. Due to the angle of the pushrods, the Faslinks were binding on top of the servo arm. When the arm was rotated, the binding was so bad, it actually bent the arm downward toward the wing. I fixed it with a couple of Du-Bro threaded ball links. Any comments or input as to what others have done?
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RE: Twinstar Geometry
Raise the low end of the servo by putting maybe a 3/32 piece of hard wood under where the 2 screws are. Your servo is not level and that is what is causing the binding.
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RE: Twinstar Geometry
Hey 91zulu. It's something I thought about doing. I just went and measured, It would take almost 3/8 of an inch shim under the front end of the servo, to get it on the same angle as the rods.
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RE: Twinstar Geometry
I used Dubro Ball-Links but mounted them on top of the servo arm and put a slight bend in the link arm. Been flying this way for about a year and haven't had a problem with it. I do make it a point to inspect all my linkages each day that I take her out to fly. If something doesn't look right I replace it.
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RE: Twinstar Geometry
Thanks tschuy. I was hoping that someone else that owned a Twinstar would comment. I mounted them on the bottom of the arm, just to help flatten out the rod angle. I posted in the Beginners Forum, that it doesn't cost any more to do things right. Why didn't Hobbico just make the servo mount on an angle, similiar to the rod angle? Problem never happens then. I am sure there are some owners that never caught this problem. I guess we got lucky.
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RE: Twinstar Geometry
Been in the hobby for a long time and learned many things. Attention to the details during installation of the servo's and linkages is a must if you want your airplanes to fly and be safe. The manufactures are all about cost of materials for a kit and making a profit. It is very typical for the larger manufactures to cut right to the bare minimums in hardware. Get something that works but may be marginal but will work.
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RE: Twinstar Geometry
I too, have learned many things in this hobby / sport. Although I haven't been at it all that long. I do try to pay attention to details, and am glad I caught this. I know I am repeating this, but, it wouldn't cost Hobbico anything to do this right. It really was bad, the amount the arm deflected. I guess I should try to spend more time on my build, ( a 4* ) and less on ARF's, but it's difficult when I am away working so much. Whaaaaaa.
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RE: Twinstar Geometry
Simply bend the pushrods slightly where they exit the servo arm, so they are parallel with the plane of rotation of the servo. The slight bend required has no effect on the strength of the push rod. Did that to my TS and flew it for a couple of years with no problems. Cheap, easy, and simple......
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RE: Twinstar Geometry
Make sure the bend is far enough away from the end, so when the servo arm is at the far end of it's forward travel, the push-rod still clears the servo body.