Rear Frame Extensions

The Allen Models castings for this part would not work on my model because the rear end of the firebox on a camelback is very close to the end of the frame with the rear wheel not far away. The Allen castings are too long.

I thought I would make the parts out of aluminum bar stock, but when I arrived at my local metal supplier yesterday, he had a pile of jig plate cutoffs in his scrap bin. He sells this material by weight regardless of quality or size, so I scored a nice piece of MIC 6 jig plate (3/4 x 4 x 24) for $25!

The first thing I did was layout an outline of the parts and cut rectangles out of the larger piece.

I drilled 3/4 inch holes for the inside corner radii and then rough cut the parts on the band saw.

I cleaned up the edges with an end mill, files, and a belt sander, with the two parts screwed together. The outside radius where the brakes are attached was milled using a rotary table. I used the odd mill shown above to mill a groove detail on the surface of the part.

I placed some of the spring rigging parts on location to test fit inside clearance.

Finally, I did a little freehand end mill carving to make the parts look more like a casting and less like jig plate. These parts will be painted black and mostly hidden by the rear driver and brake parts.