Kozo K27 Cylinders

I happened to find an ad on the auction site listing a matched set of 2 3/8 diameter bars that already had a 1" hole through them. This saved quite a bit on cost and machining time. The first cylinder has been machined to size with a 1.338" bore and just under 3" long. September 9, 2019.

The pair of cylinders have been completed with the flats machined to support the steam chest and steam passage. September 14, 2019.

The first steam chest with all of the lathe work completed. A series of 5 internal grooves had to be machined in this piece which is about 2" in diameter and over 3" long. The outer diameter will need a couple of flats milled into it like was done with the cylinders. September 17, 2019.

The lathe work for both of the steam chests has been completed. September 21, 2019.

This shot shows how the steam chests fit into the flats that were milled on the top sides of the cylinders. September 21, 2019.

The flats have been milled into the steam chests to all them to mate up with the cylinders at the correct angle. This view is the side that will face the locomotive and a steam passage block will fit into the visible flats. September 28, 2019.

Four brass end plates have been stacked and bolted together so that they can all be bored for the cylinders and steam chests at the same times. The three holes will be used to attach them to the faceplate on the lathe at various stages of the machining. The steel plate will be used as a spacer between the brass and the faceplate during boring of the hole for the cylinders. A second spacer will be required for the boring of the hole for the steam chests. October 5, 2019.

The end plates have been bored for the cylinders and steam chests as a matched set. Two 30 degree angles have been machined which will be used to orient the cylinder assembly during further machining operations. The next step will be machining the steam passage blocks before soldering the assemblies together. October 20, 2019.

The cylinder assemblies have been temporarily assembled to check the fit. The next piece will be the steam passage block that will fit into the V seen on the backside of the assembly on the right. November 10, 2019.

The steam passage blocks have been cut to their rough shape with two angles on each block. One of the blocks has been inserted behind the cylinder and steam chest for a test fit.  There will be more angles to cut and a slot before the pieces are soldered together. November 25, 2019.

The slots and angles have been cut in the steam passage blocks and a test fit is shown at left. On the right the V in the cylinder assembly can be seen where the steam passage block will sit. The next step will be to solder all of the pieces together. November 26, 2019.

The cylinder assemblies with outward canting valves has been assembled with brass screws to hold everything into position while soldering. Note that a temporary steel spacer bar is used on the front side and the back side has screws directly into the steam passage blocks. November 27, 2019.

The cylinder assemblies have been soldered together and the back sides trued up to accept the back plates. The back plates below will be attached with two screws and then soldered to provide the mounting surface to the frame. Dec 1, 2019.

The back plates have been soldered on and trimmed to the final size. The next step will be drilling all of the steam passage holes at some awkward angles. December 8, 2019.

The backplates have been drilled and tapped for frame mounting and for the exhaust T-pipe. There is still a lot of shaping, steam passage and fittings drilling to be completed but it was good to see them mounted! December 14, 2019.

The last few steps of this portion included the drilling of the steam inlet hole and milling the 30 degree angle at the top of the end plates as seen on the assembly to the left. next was milling and drilling the water drain holes at each end of the cylinder where the cylinder cocks will be mounted as seen at the bottom of the assembly on the right. December 27, 2019.