Center Spar

Build Hours: 542

The spar is labor intensive and the plans require a lot of study to catch all of the details (hope we didn't miss any)! We finally found the answer to "Where's the beef?" - it's in the center spar.

This is the spar cutout. An air nibbler was used for the bulk of the cut. Shears were used to clean the straight cut lines and a drum sander was used for the large radius. Lots of filing and sanding completed the cutout.

These are 2024 T3 3/16" blanks cut from the carry thru stock. The stock plate was cut with the grain in 1 1/16" strips with a jigsaw and then put in an X-Y vise. A 1/4" endmill was used in the drill press to square the blanks to 1". The 2024 aluminum is really hard on jigsaw blades and 10 tpi was found to do the best job.

Here's the center web with the spar tangs and upper and lower caps. The caps have already been notched and the tangs have been radiused. The other 2 pieces are the cap spreader and spacer.

The assembled end of the spar ready for riveting. The end cap notch radius has been carefully sanded up to 800 grit and polished. The last 4 holes for the tang bolts will go to the drill press for drilling and reaming to get the best fit. The outer spars must be built next to set the dihedral and complete the spar tang drilling.



The carry thru was cut per the plans with a jigsaw. The plate was cut across the grain. A holesaw in the drill press was used for the lightening holes. More filing and sanding to cleanup the edges!




The web stiffeners were bent in the homemade brake after a modification to the platen for the 1/2" channel width.

Panel, Vents and more...

Build hours: 521

The tanks held 5 gallons with breathing room and DID NOT LEAK!

Ventilation is provided by two 2" snap vents. The vents do not close but very little air comes in in the down or back position. The vents do a good job at directing the air to the face or torso - we used the air compressor to check.

The instrument panel was made from .040 6061 per the plans which makes a very light panel. The panel was flanged to stiffen it and Cessna style shock mounts are used to mount and isolate from the airframe. A gap was left around the panel to allow it to move on the shock mounts.

Seatbacks were formed so that all of the square tube bending would be completed.

The fuselage is leveled laterally and longitudinally and a solid reference is mounted to align the wing spar.

The level was on sale at Sears for 25 bucks. Its very handy and builds your confidence in the accuracy of a bubble level.

Preparation for the big cut. A line is drawn across the bottom of the fuselage, 14" from the back of the B bulkhead and one down the centerline to align the pattern on.

Plan note:

Call Hummel to get an Autocad drawing of the pattern if you didn't get the kit and consider moving the line back if you a big fella!

Windscreen and Canopy Done! Moving on...

Build hours: 509

Here's an update for Louise... (see previous comments)

The bows are bent. The canopy and windscreen are in place. The windshield trim is formed and the latch latches. The tank cover is in place and the instrument panel is being planned. Moving right along...