Horn Blocks

These are a few photos of the horn blocks. I have no photos of the machining of the outside of the blocks. Suffice it  to say, the shoulder of the blocks are made for a very close fit into the frames so nothing can move even if a screw was to work loose. Some folks rivet the blocks to the frame. This is not necessary for miniature locomotives. Screws let the blocks to be removable to allow for further machine work on the frames. Having the blocks removable will also allow the frames to sit completely flat on the mill table for further work. The inside surfaces of the horn blocks are machined after they have been attached to the frames. This allows for a single finalpass of the milling cutter from one side of the frame to the other to ensure each pair of axle blocks will be in exactly the same place in reference to the frames.  
Unmachined horn block above.
Horn stays installed.
Finished horn block above.
Horn stays only have a single step on the inside, the  drawing called for a more unnecessarily complicated design.