Engine mount Installation cont:
I completed the in-situ design of the engine mount. At this point in the project, I am designing as I go and not laying out anything on the computer first. I do check loads and stress however! The addition of another motor other than the original MZ 34 is less than optimum. I never designed for these engines so their installation is not extremely clean and light. I know I could do a lot better and make a cleaner installation from scratch. I increased the area of the 4 longerons that terminated at the firewall. I attached 4) 4130 steel angles to the ends of these longerons. The main issue with this method of attachment is the lack of a load path for vertical shear. I polled my designers at work and Dave Magerstadt, an excellent designer and former ESA treasurer, came up with a solution!
This is another view of the firewall. I have already added the ceramic firewall that will protect the fiberglass firewall bulkhead. Later the ceramic and the wood intercostal will be coated with Contengo. an ablative latex coating designed to char rather than burn.
|iso view of firewall|
the white coating is Contengo,
Ed is the Picasso of Pistols, the Rembrandt of Remingtons the Wyeth of Winchesters.... You get the idea. Visit Ed site and you will see some beautiful work!! Some of it is mine too!! I asked Ed to topcoat the mount with Urethane paint. While he was at it, he top coated my friend Michelle Craig s 1946 Talyorcraft wing fittings and the cowl of the 1984 Tiafum Motorglider I am repairing for Dan Stofman.
Unfortunately the engine mount was also a compromise. I had to add two .032 gussets to react the non optimal truss. I would have liked to have terminated the truss member into the the other tubes cluster, but I had to revise the tube angle to clear the intake manifold. This creates a local overturning moment that needs to be reacted by a gusset plate. Not efficient, but again, all the load paths are accounted for.
|all of the foam from the store|
I usually confirm the clerks doubts and tell them I have a "Big Wedding"
So the first step in developing a proper cowl shape is to lay out a Masonite template of the side view and plan view or in nautical terms, "Max Half Breadth" My desire is to use the existing spinner and backing plate. I have molds for both of those parts. So I need to develop lines that blend from the spinner to the fuselage lines. This was pretty easy to do on the upper loft.
|upper cowl spline template|
|lower spline template|