|The cylinder block was cut from a piece of durabar cast iron. I find this
material very nice to work, it cuts and mills just great. The steam passages
are dilled 1/16" dia, and the pors were milled with a 1/16" end mill.
The head is a simple turning job, while the backhead was first milled from square block, then turned on a spigot threaded into the stuffing box hole.
|Here the connecting rod is being profile milled on the Prazi CNC. Note the aluminum sacrafice plate under it shows the outline of the side frames, and even some of the spoke patterns- the same block has been used for all these operations. When it gets to uneven Ill flycut it flat and use it more.|
|Here is the block, crosshead, guide bars and connecting rod all assembled.|
|And here the complete assemply is installed between the frames and hooked
to the crankshaft.
This photo shows another mod I made- the axles are fitted into slots, and held in place with an E-clip. The original design called for fixed bushes, with the wheels pressed together and impossible to remove. I can pull the E-clips, slide the buses to the center of the axle and lift the axle out through the slots.
|Here are the valve parts- the chest, spindle and the actual valve. Also shown os a banjo fitting and copper pipe that will supply the lubricator oil to the engine, directly into the valve chest.|
|Here the engine is completely assembled, but the left side frame is not yet installed.|
|The complete engine, between the frames, with the smokebox installed and the
steam pipe up from the eninge into the steambox.
I had a couple days of frustration to get the engine running. I fiddled with the valve stem adjustment, the eccentric position and even shortened up the vale as I thought the design had to much lap.
The problem turned out to be the steam ports were closed off by the small alignment spigot turned on the back of the cylinder covers. This spigot was deep enough that the small mill cut to deliver steam from the drilled holes was completely covered on one end, and almost covered on the back end.
I milled a small pocket in the heads and reassembled it all and it ran just fine.