Simple Oscillating Steam Engine - Cylinder End Cap

The end cap was simple turning job from a short piece of brass bar.

It had no critical dimensions, but the shoulder to sit inside the cylinder bore was made as snug as possible to aid location and sealing.

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First the outer diameter of the cap was turned.









Then the shoulder was turned using the cylinder bore as a gauge to get the correct diameter. A sharp tool was used to eliminate any radius between the shoulder and the cap.









As with the bearing, 3 evenly space holes were marked around the cap using a spirit level and a punch mounted in the tool post.









The cap was parted from the bar using a slow speed and feed. Part way through the tool was retracted and a file was touched against the work to remove burrs. Then the part was cut off completely.

The slight pip left in the centre of the cap top was filed off and the cap top polished on fine emery cloth to finish.










Finally the cap mounting holes were drilled on the pillar drill using a 1.8mm drill to take the 10BA mounting bolts.