ORIGINAL: Vampire

I support the previous post by kochj on the use of ''Hard'' (Brass or S.S.) tubing in place of the Vinyl or Urethane tubing as this tubing is susceptible to ''expansion'' under various loads (in particular in LONG LENGTHS) and may likely not deliver repeatable performance in this application. Unless noted otherwise, I believe this tubing is designed for fluid (air or gas) transfer and may not be intended for use in an ''linear control'' scheme.

The use of the tubing I see in the pics may produce ''over drive'' performance which leads to non-linear movement due to ''swelling'' under input load and when the input command stops, the tubing will try to return to its original shape (dia.) but may tend to ''overdrive'' the point your trying to achieve not to mention that when a side or ''centering load'' (due to the trailing fork design) is applied by the nose wheel, it can have the reverse affect and back pressure the tubing in effect will expand it and lose the position control your trying to maintain. It's all about pressure containment.

I wish to add you will want to INCREASE the inside diameter of the hard tubing as well as the 2nd benefit is it will yield QUICKER response time to input. (larger dia. = more pressure transfer and quicker response). A shorter, larger Dia. cylinder is a good thing as well. This will help response times too.

Of course some degree of flex tubing will be needed but should be keep to an absolute minimum length for the reasons mentioned and the same amount (lengths) to be used in BOTH lines to ensure repeatable movement in BOTH directions.

I have made several assumptions above on the type and sizing of the tubing provided for the application and these are just my htoughts on the subject issue.