Well, it's almost the end of November and I have built almost nothing this year. But the summer has ended, the yacht is in dry dock, and the pretty girls have removed their thongs and put them away until the spring. And so, back to the modeling grind.
I seriously underestimated the frame for my loco. The 3D printed frame sat all summer with the tractor perched on it in the hottest room in my house. All seemed well, but once I started cleaning the wax off, it began bowing and yawning enough to convince me the FUD material was too unstable to use. It was also a fair bit undersize to my 3D model, almost an 1/8" short and a 1/16th inch narrow.
The prototype uses C channel structural steel, with no thick cast sections often found in small loco frame design. The die-cast tractor weighs about 3/4 of a pound with the wheels removed, so I needed something thin yet strong to support it.
Earlier in this topic, David Fischer offered to assist in some casting, so I contacted him to see if I could cast the frame pieces. He expressed doubt that they would be stable enough in the thin sections required. He recommended building the frame up with individual pieces of styrene and metal for greater rigidity. This seemed more work than I wanted to do, but eventually he convinced me to give it a go, and this is what I am doing. I'll write it up in detail when I get more time.
Here are the side frames in primer for flaw detection. I go through many prime and strip sessions.
I attached the frame sides to the journal pedestals yesterday. I hung a few other parts on to get a feel for it. The end beams seen here are printed, but I will be making styrene versions. The FUD material is too unstable in these thin profiles. (The toothpick will be painted and weathered in the final model)
Thank you David, for the assistance! What a Forum is all about.
