Tonight I created my master of masters Wing Rib Forming Block or ÜberBlock™ as I call it.
I first used 3M Super 77 adhesive (available at HD and art supply stores) to adhere my mylar #7 to a piece of 3/4" MDF. Since I wanted to preserve my #7 in case of ÜberBlock™ failure, I let the Super 77 air cure for about a minute. I had my wife help me hold the mylar while I pressed it into place. I didn't want any "incidents" at this early stage of the game.
Using a sharp pencil, I traced around the outside of the mylar. Then using a transfer punch (read sharp finish nail and a hammer) I transferred all jig holes, lightning hole centers, and Center Line reference points to the MDF. I added more jig hole locations to the mylar prior to sticking it down. Note the photos for additional jig hole locations.*
Then I jig sawed about an 1/8" to a 1/4" outside of my line. We won't discuss how I didn't notice my table saw fence guide was in the way and "somehow" got gouged up by the blade. I don't know what you're talking about.
After the rib form block was free from it's sheet good bounds, I peeled the mylar off and went to my benchtop belt sander. Hooked up my shop vac to the dust port and, using an 80 grit belt, carefully sanded to shape.
Then it was drill press time. Using my transfer marks, I carefully drilled and added bushings as required. I then used a ultra-fine sharpie and noted my center lines on the blank.
*Don't make the same mistake I did when adding more jig pin locations! I failed to remember the Rib to Spar Attachment Angle when I placed my extra jig pin holes. The holes will be relocated later after I stop kicking myself.
