The Musger 12 single seat glider was designed and built by the Austrian Aero Club in 1937 as an intermediate training glider that was simple to build and maintain but with a far superior performance than the then available basic training models.The 12 A was first built in 1938 with some minor improvements over the original 12 model. A total of 15 12A's were built but as far as we are aware no full size exists any more. The basic design of the model is from a very detailed plan from Vincent Besancon who runs the very popular Retroplane web site www.retroplane.net. Vincent's model was to a scale of 1 /4.2 but as this was to small to fit in with the teams other models the size was doubled to 2/2.15. Due to the increase in size and structural loading parts of the model had to be redesigned and wood sizes changed but this was easy thanks to Vincent providing CAD drawings for parts of his design. A decision was made to build the structure like the full size using built up formers and ribs rather than cut them from solid sheet. This would provide a real building challenge and add fun to the build. Many parts such as the former gussets and rib noses have been cut on the teams CNC machine but this still leaves a lot of manual construction to do.Work started building up the spars for the wings to ensure accurate sizing for the spar slot in the built up wing ribs. Formers were also constructed making use of the wide workbench to lay out parts on both sides. Fuz frames were then constructed and jigged up to form the basic box to which the formers can be added.
All the wing ribs were built up in jigs before being threaded onto the built up spars. See below for details of the construction.
|Fuselage under construction, nots the triangular supports to ensure it is aligned as the individual pieces are added.|
|One wing rib in the construction jig and another completed rib alongside.|
|One wing panel ready for sheeting.|
|Trial fit of the wings and the pilot.|
|Stitching on the Diatex covering before adding the pinking strips and doping the fabric.|