Wing Center Skinning

Build Hours: 865

Lots of hours were involved in completing one of the UC wing center sections. There's a lot of missing steps in the next sequence of pictures which I hope to fill in as we complete the center section on the other UC. Now that we've gained some "prior building experience", we'll know when its a good point to take a picture.

Some of the pictures are dark due to me bouncing the camera off of the concrete floor which killed the flash, arghhh!

The UCSide

(kinda like the popular cartoon - The Farside without as much humor:))

"The intrepid builder realizes too far into the project that the cockpit is rather snug!"

As always, we started with a pattern. During the entire nose skining process, we kept the fuselage level and the wing spar plumb by clamping the rear spar to a 1" x 2" steel tube clamped to the siderails. Level and plumb was checked often!

We use the offset pen/pencil to follow the fuselage shape.

We used the vacuum bagging method to form the nose skin around a 2" pipe.

Here the skin is being trial fit.

After the nose skin, which required lots of strapping and adjustments, we installed the top aft skin. We then flipped the fuselage to fit the bottom skin. The extra rib and reinforced ribs are for the wing step area.

This is the gear leg in place under the wing.

This is the gear leg attached to the spar and the aileron bracket.

This picture shows the shape of the rear spar and the aft skin fit. this will all be covered by the wing fairings when completed.

The wing step has an additional .040 panel to stiffen things up.

Another view of the rear spar and lower skin attachment.

The rectangular riveted section is the landing gear doubler.

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 :)

Ribs and Spars

Build hours: 697

Progress has been made since the last update in August. We decided to build our ribs for the experience, weight savings and to use up all of the accumulated cutoffs instead of buying 2 additional 4' x 12' sheets. So far, the rights side ribs and spars are completed and the left side rib parts are made.

This is the particle board jig to hold the rib parts in place during assembly. The top and bottom caps were bent in the brake and then shrunk to the rib pattern. An endless number of braces were folded (enough for 2 sets of ribs).

Alignment dowels were inserted into the jig to allow the pattern pieces to be moved to the opposite side of the build board to make left or right ribs.

A form was made to bend the nose pieces over and a particle board flanging die made to make the lightening hole flange. Shrinking of the flanges manually and with the shrinker was required.

Finished rib assemblies.

We used 3/32" solid rivets to assemble the ribs. After you get the rivet driving going, its as fast as pop rivets and gives better edge distances.

These are the 4" or 4 1/2" flanging dies for the spar lightening holes. The flanges stiffen the web considerably even though all of those holes only remove 3.7 ounces from each spar.

A 14' jig was made that would hold the spar center section and one outer spar at the correct angle. The spar fittings were prepared and clamped. The jig was set at the correct height for the drill press. All spar fitting holes were drilled undersized and reamed to .002 or .001 under as required.

Additional rounding and cleanup on the spar fittings was completed. All spars are done.