Thursday, January 15, 2009

Controls and Wing Center Section

Build hours: 769

The control system, seat back, seat brace, center spar installation and spar braces have been completed for UCA and UCB.
These are the rudder pedals purchased from Hummel as part of the controls kit. The aluminum welding made our decision to purchase. The lightening holes in the rudder bracket is a recommendation from Hummel that is not on the plans (4 oz). The wimpy looking brace makes for a very solid arrangement.
Plan note:
The lower tab on the brace is too long and flexes to much to be effective per the plans. One builder put a rivet in the tab behind the bolt. We remade the bracket and shortened the tab.
Nylon washers, 1.25" in diameter , .125" thick were placed on each side of the rudder bar for a good fit and smooth rotation.

This is a closeup of the front of the middle rudder pushrod link.

The next link in the rudder pushrod was bowed against the fuselage for maximum arm/elbow clearance.

This picture shows the middle to rear rudder pushrod link attachment. Four threads were left showing on the rod ends for adjustment.

Also show is the placement of the seatback support. The support was put under the rails so that the canopy fit would not be interfered with. Some felt or nylon needs to be added where the seatback rest against the support.

The control stick was curved to better align with the hand. Some trimming of the pre-welded assembly was required to get the stick and horn to center appropriately. Also, 2 assemblies were purchased, one was welded per the plans, one was welded per the welder - someone always knows better than the designer.

Plan note:
The first elevator pushrod link requires an unusual bend to miss your leg and enter the "C" bulkhead correctly.

We made several trial pieces, bent a disaster, walked away, came back and ended up with "perfection":) (And we did it correctly twice!)

The rear bulkhead openings and horns were made a long time ago... Its great when the plan comes together!

The rudder and elevator shouldn't have to be removed so the safety cotter pins were installed, and all horizontal stab bolts were tightened and indexed with a red paint mark.

The inserts for all of the control rods were turned , bored and tapped on the lathe. Only 16 more to do for the aileron pushrods.

The seat was bolted to 2 pieces of angle attached to the bottom rails.

This is the "C1" buckhead. Notice the misaligned centering marks. The error was caught after the picture but before we screwed up :)