This is a model of the launcher for the Nike Hercules missile. It fits the model here:
You can decide at what angle you want the rail to be, from near-horizontal to vertical, and glue it in place first. Then assemble the other parts and glue them into place.
Orient parts for printing as follows:
Frame - As-is
Strut - As-is, (partially upright), use some brim for adhesion
Strut Arm - Lay flat
Rail - Lay flat on side, use some brim to prevent ends from warping upward.
The main axle on the frame should have support. The horizontal portion of the strut should bridge fairly well. If you are not confident the bridging behavior of your material, you might want to use support there also.
The one shown was printed in white PLA and spray-painted with Krylon Italian Olive.
This is just the basic frame elements of the actual launcher. There is plenty of opportunity to add more detail , such as hydraulics, power, and control units. Model them yourself and glue them on !