REFLECTOR: Steel Aileron Torque Tubes/stick to torque tube

[Laurence Coen]

Brian,

This fix worked real well for me and is easy to do.  The junction of the torque tube and the stick have wide area flat washers attached with micro that connects them rigidly to the tubes.  The washers form a large bearing surface to carry the load with no detectable slop.  I do love cheap and easy.

Larry


From: Brian Michalk 
Sent: Monday, March 24, 2014 12:17 PM
To: Velocity Aircraft Owners and Builders list 
Subject: Re: REFLECTOR: Steel Aileron Torque Tubes


What follows is not a recommendation on a steel tube:
If I were at this point, I would make a design change here.

Look at the pivot of the control stick to the torque tube.  All of the torque is sent through a -3 (I believe) bolt that needs to be tightened enough to remove play, but loose enough to allow rotation.  It's a design that I wish I would have addressed.  If I were to do it over again, I would:

1) Run the torque tube in the center of the keel, which may displace your speed brake actuator.
2) attach it with the provided hardware to the top of the keel.  The forward bearing would be just aft of the control stick cutout, leaving three or four inches extending (cantilevered) past the bearing.
3) using a larger ID tube, make an adapter that will slide over the torque tube such that the torque tube pierces the adapter at a right angle.  The control stick will be inserted into this adapter.  This will be drilled and will transmit torque from the stick to the torque tube.  The hole in the adapter will necessarily be longer along the stick axis in order to rotate in pitch.  Alternatively, one could weld on some thin steel that would sandwich around the torque tube, which is easier than machining an oval hole in a tube.
4) Because the pivot point is very close (higher) to the keel cutout, your keel cutout will need to be smaller to provide the required control stops.  I haven't done it, but you can do the math.

Using this design, the pivot bolt is only in shear, and not in torque, which is the main difference from the plans.  I believe you will like the feel of this design better than the design from the factory.

The other benefit is that the design is symmetrical.  The factory design is such that when the stick is moved left, it raises and is allowed to impart more left aileron.  When moved right, it descends into the cutout more, contacting the keel cutout earlier, resulting in less right aileron deflection.

I did machine a saddle that provides for one square inch of bearing surface, but still don't like the behavior.

On 3/23/2014 7:38 PM, Paul Folkes wrote:

  Hi all, 


  I was flicking through the wiki and read about the supposed issues with the standard aluminium torque tubes warping.  As I am near to bonding the keel in permanently, I would rather address this issue first.  Is there a problem with the alum tubes warping? Is the steel tube upgrade worth it, or am I looking for a problem that may not be there?


  Thanks,


  Paul Folkes
  XLRG
  VH-VVX
  Building but a looong way to go!

   

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