THE RIB JIGS
June 12 to July 4, 2017: I have spent a lot of time figuring out how I want to construct the rib jig. I looked at many methods on various websites and YouTube. Some folks were gluing the gussets and then stapling them down for clamping pressure. I experimented with the staples and glue and came to the conclusion I did not like the way the staples damaged a portion of the gusset plate. Several folks used wood clamps or metal clamps with bolts and wing nuts. I settled on that approach. I bought a 4″ x 4″ x 1/8″ x 48″ long piece of extruded aluminum tube. Cut it down to 1″ wide pieces and then cut them cross ways to make two clamps. The clamps were then fabricated to have a short leg and a long leg with the short leg to bear on the gusset. Two lengths of short legs. One for 9/16″ (1/2 cap strip + 1/16″ ply gusset) and the other length of 5/8″ to fit the flip side of the rib (gluing the opposite side) (1/2″ cap + two – 1/16″ gussets). The pictures show the carriage bolts used to tighten down the clamp on the glued gusset. Just turn the wing nut enough to squeeze a little glue and stop.
I also used the little cam locks to lock the pieces of the cap strips and webs down tight. Looking forward to my first glue up.
I was particularly pleased with the way the transfer of the rib layout to the jig board worked out. I used a 18″ wide x 78″ long piece of white Melamine. I took the long rib drawing from the Pietenpol plans down to an engineering print shop and had them copy it onto an acetate (I think) film. I glued the film image to the melamine with 3M adhesive spray and carefully rolled the acetate onto the board. It worked well. It made it very easy to mount the jig blocks to the outline of the rib and for the internal webs.