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I have gotten a little "burned out" on the paddle steamer engine, so in the meantime I have started on building the Kozo Pennsylvania A3 switching locomotive. This will be the 1.5 inch/foot (i.e., 1/8 size) and will run on 7.5" gauge track.
I have made a start on the frame, which has 5 main pieces: 2 side rails, a front bumper, a rear footplate, and a crossmember. I didn't take any pics milling the side rails from 1/2x2.5" CRS, so here are a few more recent progress shots.
The left side rail needs a 1.125" hole for the blowdown valve. My latest drill is 15/16, so I bored it out:
Next, fabricated the rear footplate from 1.5" square CRS milled down to 1.25x1.25.
I used the footplate holes as a drilling template on the side rails:
The frames are too big for my little tapping stand, so I used the mill spindle to start the 10-32 tap straight.
Here are the side rails, foot plate, and crossmember in "position". I'm waiting to get fasteners from Enco. The crossmember needs to be remade due to "operator error". :![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Next is the front bumper, made from 1.5x1.5x13.375 CRS. After milling and drilling the mounting slots, I used the CNC mill to round the ends:
The front bumper will get a lot more threaded holes, but I'll hold off until I make the parts to mount there.
The engine has a few hundred parts to make, but these are the largest sizewise. The side rails are 3' long, and are the largest pieces I have ever machined. Though the Bridgeport table is 9x42, the spindle X travel is abou 24" max, so I needed to move the rails sideways a couple of times to mill and drill all the features. For alignment, I use a pair of ground rods that fit in the table slots. The pieces are pressed against these rods before clamping. I used parallels under the rails to clear the table.
I have made a start on the frame, which has 5 main pieces: 2 side rails, a front bumper, a rear footplate, and a crossmember. I didn't take any pics milling the side rails from 1/2x2.5" CRS, so here are a few more recent progress shots.
The left side rail needs a 1.125" hole for the blowdown valve. My latest drill is 15/16, so I bored it out:
![large.jpg](https://proxy.imagearchive.com/6a3/6a361403ac3c1607c7a83f05e5e7c3ff.jpg)
Next, fabricated the rear footplate from 1.5" square CRS milled down to 1.25x1.25.
![large.jpg](https://proxy.imagearchive.com/2ff/2ff5a1d24dbed29dbace7ed84c9cf0ec.jpg)
I used the footplate holes as a drilling template on the side rails:
![large.jpg](https://proxy.imagearchive.com/137/1370e58544d6a427d26d126f7a89373d.jpg)
The frames are too big for my little tapping stand, so I used the mill spindle to start the 10-32 tap straight.
![large.jpg](https://proxy.imagearchive.com/d8d/d8daa9cb3696ba52f92b081f57bc8a6c.jpg)
Here are the side rails, foot plate, and crossmember in "position". I'm waiting to get fasteners from Enco. The crossmember needs to be remade due to "operator error". :
![large.jpg](https://proxy.imagearchive.com/c45/c4578fcdbc820598b28120194c7e26f3.jpg)
Next is the front bumper, made from 1.5x1.5x13.375 CRS. After milling and drilling the mounting slots, I used the CNC mill to round the ends:
![large.jpg](https://proxy.imagearchive.com/cff/cff53335c71f6f9d89e175f95c1923b5.jpg)
![large.jpg](https://proxy.imagearchive.com/453/453028a27bc477440d17e6ec781eb5ca.jpg)
The front bumper will get a lot more threaded holes, but I'll hold off until I make the parts to mount there.
The engine has a few hundred parts to make, but these are the largest sizewise. The side rails are 3' long, and are the largest pieces I have ever machined. Though the Bridgeport table is 9x42, the spindle X travel is abou 24" max, so I needed to move the rails sideways a couple of times to mill and drill all the features. For alignment, I use a pair of ground rods that fit in the table slots. The pieces are pressed against these rods before clamping. I used parallels under the rails to clear the table.