Simple Oscillating Steam Engine - Cylinder Pivot


The cylinder pivot was made from a silver steel rod of 4mm diameter.

Click for larger drawing

It was machined to ensure that there was a square shoulder at the root of the M3 thread. This would help the pin to pull square to the cylinder port face when tightened.

 

 

 

 

 

 

 

 

A piece of silver steel was cut just over length and the ends were squared off in the lathe.

Next a sharp pointed tool was used to turn a section of the shaft to 3mm diameter. This reduced section was made longer than would be finally needed to aid the threading process.

 

 

 

 

 

 

 

 

To cut the thread the tailstock was used to assist the threading process. The tailstock chuck was used to keep the die square to the work and apply a light force. The tool post was positioned to stop the die holder rotating and then the chuck was turned by hand to cut the thread up to the shoulder.

 

 

 

 

 

 

 

 

Next, a very sharp tool was used to square off the bottom of the thread.

Then the thread was turned to final length using the cylinder tapped hole as a guide.

Finally an M4 thread was added to the other end of the pin using the same threading technique.