Re: Scratchbuilding HOn3 or On3 chassis.

If you are not going to cast the brass yourself, or make the mold for the brass yourself...

It would probably be cheaper to draw it up and have it 3d printed. The best thing I can tell you to do is draw the ENTIRE engine before you construct the frame. There are lots of parts that connect to the frame, and trust me, If you forget to add something to the frame, it becomes very hard to fix this later.

Also, in HOn3 you may have the ability to print the entire frame, spacers and all. This would be good as you most likely would have to do no work to square the frame. On3 in brass becomes a little harder to print something that big. I don't think shapeways can do it (or at least they couldn't last time I checked).

The way we did it in 1/2" scale (twice O) is to draw the frames, and have them waterjet cut from sheet brass. For our scale, everything was drawn to scale. For HO, you would probably have to enlarge some of the parts for strength. This requires making your own frame spacers, machining out the Journal slots, and very squarely soldering the frame together. Not impossible, but easy to mess up. Frame squareness can mean the difference of a running and non running engine.



Casey