Page 8, Bellcrank Support tube

[Lee S]

See attached. Along the right hand side of sheet 8 there is a section view of the 1-3/8" LG. x 1/2" x 0.095 bell crank support tube. For reference, this particular section looks like an inverted "T". With reference to the adjacent plan view, which way is up on this section, to the left or the right? I'm trying to determine if the 3/4" long portion of the support tube pointing up or down?

[Steve W]

I must have had the same question by the "up?" I wrote by the 3/4" end on my plans. Just went out back and checked my wings. I made mine with the 3/4" up. Can't swear that's correct but I don't have any rod clearance issues with actuating the aileron. Funny it would be opposite of what is depicted on the other end. So long ago I don't remember what I used to confirm what I did. Altzheimers. Wait. What was the question again?

[Lee S]

Thank you for your response. At first I thought the 3/4" side was up as well, however after further review.... On this section view, the T3 diagonal knee brace is not shown coming out of the sheet towards you. Thus, the diagonal brace must be on the back side and not seen in this view. This would make the 3/4" side pointing down. There is only 1/8" difference between the two sides, perhaps in this case, the 1/8" doesn't make a difference??? It is good to know that you orientated yours with the 3/4" side up and had no problems.

[Steve W]

Good catch! I'll have to really check closely for cable, rod and support tube clearance.

[Chewie]

True that the T3 is not shown, but with this projection showing the side view to the right the plan view, the 3/4 end should be towards you on the plan view, against the bearing. Look at the support frame views below and follow the same convection.

[Lee S]

Chewie - I used your same logic at first too. However, looking at the drawing set as a whole, RB does a pretty good job of illustrating all the pieces parts in his sections. It would be odd if he simply missed the T3 knee brace in this view or omitted it for clarity.
A simple up arrow like the one on the far left hand side of the sheet would certainly clarify the issue.

[Steve W]

If you look at the images of the bellcrank, the T1 braces are not shown either on the side view, only on the top view.