Bulkheads B-E

Build hours: 31

Bulkheads B through E and a second set of A-E were completed in the same manner as bulkhead "A". Tabs on curved areas of the bulkheads will not lay flat when bending. This was disconcerting at first but most of the tabs will be at some angle less than 90 degrees to match the skin. Tabs needing to be at 90 degrees or more will need fluting or shrinking. Next is to had the bulkhead corner tabs and control guides before moving to the beam.

Plan Note:

In preparation for cutting out E2 it was noticed that the bulkhead template specifies .016 material but the layout on Sheet 0 shows the bulkhead on the .025 sheet. A quick email response from Hummel indicated the bulkhead could be .016 to .025 - builders choice. We chose .016 2024T3 because of the strength and weight savings.

Bulkhead "A"

Build hours: 17
Up the learning curve we go! It took 3 hours to turn out the first bulkhead. Hopefully the experience will allow the next 13 bulkheads to go quite a bit faster.
The bulkhead "A" template was outlined with a Sharpie Ultra Fine Point onto the .025 6061T6. The template was then rough cut with an air nibbler and then trimmed with tin snips. A metal hole punch was tried to punch a clean hole at the bottom of the bulkhead notches but the punch body obsured the hole outline. In the end, the hole was drilled with a 3/16" bit and deburred just as quickly. The notches were clipped and the entire outer edge of the bulkhead was smoothed with a fine metal file.
The blank was then bolted and clamped between the 2 forms. A dead blow hammer was used to tap the tabs over. After the bulkhead was removed from the form, the tabs were adjusted with pliers. The final step was to admire the completed bulkhead!
The pictures represent the steps taken but are not bulkhead "A" or the same bulkhead.

Bulkhead forms

Build hours: 14

The patterns were outlined onto a piece of 5/8" particle board. A combination of bandsaw and jigsaw was used to cut the line on the particle board. Two forms were made for each bulkhead. The form were aligned with two 1/4" bolts and smoothed on a disc sander. The forms were then labeled and marked as TOP and BOTTOM and which way to bend the tabs to avoid a screwup later when metal was involved! Finally the bending edge was radiused with a coarse file, sanded and checked with a radius gage. A final check was made to verify the bulkheads matched the original plans outline.