Hi guys
The next piece to work on will be the power piston, the piston is constructed of multiple parts that screw together to form an air tight assembly. The parts that make up the assembly are the Piston, Small End Bearing, and Piston Extension which is a silver soldered assembly, there is also a gasket that goes between the Piston and Piston Extension.
Here is a shot of the print for the piston parts.
The piston itself started out as a suitable piece of cast iron round bar.
The piston was turned and bored.
Then parted off from the parent stock.
The piston was lightly held in a V-block to facilitate drilling the hole pattern in the flange. Note the small rod under the piston to keep it from being pushed own while drilling. The piston was left oversize and will be fit to the bore later on; oil grooves will also be added.
Similarly the end plate for the piston extension was turned, then drilled and parted off.
The end plate was tapped using my under construction UPT.
The Small End Bearing (where the wrist pin goes) was supposed to be a silver soldered fabrication. I chose to machine it from solid cast iron stock. Here the diameters have been turned and sawed from the bar stock.
Next the hole for the wrist pin was drilled and reamed.
Pair of soft jaws were machined to accept the part for both operations. The small diameter is held for the first side.
Then the part is flipped over and the second side is machined, the screw holes are also drilled in this step. For both milling operations, a drill blank was inserted in the hole and indicated parallel to the X axis of the mill.
Here is a closer shot of the bottom side.
And one of the top, or the side that you would see if you looked into the piston. I’m pleased with how the bearing turned out.
Thanks for checking in, more to follow.
Dave
