The Little Samson Steam Tractor

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This is definately the hardest part so far. It has to machined true in three dimensions, at the same time all faces and bores have to end up in the right place!

Cleaning up the top face. The plug in the bore is there so i can get positional readings for the various surfaces. All fixtures are relative to the cylinder bore.

 

It might not look much but theres nearly a days work in the valve chest. The three slots are the exhaust port (centre) and the two transfer ports for each end of the cylinder. The valve slides across the face of these ports.

 

Cutting the saddle. A long and tedious job a lot of metal has to come off and the raidus has to be exact or the gasket won't seal against the boiler. It also has to be in the correct position relative to the cylinder bore. And no, the cutter is not broken, the white tape acts as a vibration damper and stops the tool squeeling so much as it's cutting!

 

The liner installed and the steam ports milled out.

 

The valve chest cover plate.

 

Part finished trunk guide and cylinder cover plate.

 

The wonders of a bridgeport mill - nodding the head 10 degrees from vertical for drilling the steam ports.