Trim Mechanisms
Does anybody have photos or can tell me how and where the forward spring of there trim is attached to the control rod?
I have trouble triming my cirrus at high speeds and my impression is that the attachment of the forward spring of the
trim mechanism is to far aft on the control rod.
The back spring is fixed to the control rod with a bracket that is welded on the rod so there is no doubt about the position there.
The forward spring is attached on a bracket that has been clamped around the rod and does not seem to be original.
It is in the most forward position it could be without interfering with the hingepoint of the lever from the stick to the control rod.
I'am however under the impression that it might have been attached somehow at the hingepoint before. can anyone confirm this?
My cirrus has serial number 189 (build by schemmp-hirth) and has the "trimlever" sliding on a brass tube and it is fixed on a
certain position by tightning the screw of the lever. It does not have a camming devise to fix the position as later cirrusses do (Grob)
Any help from some one with a cirrus that has the same type of trim would be very welcome.
Jantoon Reyers
Hi Jantoon,
Am currently doing some work on N 13 D which has the same trim set-up, I have the seat pan out, so I could take a couple of photo's if you like.
I have it at home so it is not a big inconvenience.
It snowed last night and it's cold, so if it warms up in the next couple of days I will pull it out of the trailer and take the shots.
Hope that is soon enough.
Cheers,
Jan__
I uploaded two photos in the #206 "Stoltz' Ship" folder that show our "Sliding Knob" trim spring linkage. From your description, I believe it is the same one you have. The photos do not show it very well, the control rod that runs along the left side of the fuselage hides most of the forward spring, and the actual anchor point. But you can see that the forward spring on our ship is connected to the bracket that holds the bearing at the end of the control rod. If yours is attached to a separate bracket or clamp on the control rod itself, then it probably does not exert as much "pull" in the forward direction as it is designed to do. On the other hand, someone may have also changed the length, or strength of the spring, too. I am assuming that our ship has the original factory set up.
My son and I are both at the upper end of the weight capacity. We use the trim on takoff, set at about 3/4 of the way forward. I often leave the knob loose and fly essentially without the trim once I'm off of tow. Control forces are light enough that it really doesn't seem to make that much difference to me. High speed "trim" isn't a problem for us, maybe due to cockpit loading and the fact that we don't get to do all that much high speed flying in Michigan ;(
Hope this helps.
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Pictures courtesy Chuck Stoltz
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Jantoon,
Unlike dad, I lock the trim for thermal or cruise. I would like a little
more aft trim authority on #206. I am wondering if the Cirrus trim
authority is smaller than the acceptable CG range? If you are light in the
nose, maybe the trim isn't strong enough to compensate, and maybe a
previous, amply ballasted owner decided they wanted a little more aft trim
authority (I wouldn't mind). If only we all weighed that same as Dr. Klaus
Holighaus!
-Tom
I attach the rear spring to the tube using a hose clamp. The welded on lug does not give a fast enough speed.
Brendan English
Thanks I've finally been able to see the group pictures thanks I supose the hole in the fork has been filled with
paint on my cirrus but I think I should bee able to find it
Jantoon
Hi Jantoon,
Finally got the shots of the trim spring, sounds like you don't need them now but I thought I'd send them anyway.
Cheers Ray Iddon
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Pictures courtesy Ray Iddon
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