Jaegers 6" f/10 "GJD" OTA Construction - The Main Tube (groove cut around tube complete)
 

Main tube being cut to proper size - 7. (Click to see an enlarged image.)

 
A view down the main tube showing the penetration of the shallow cuts around its circumference by the hacksaw. This process (though time consuming) pretty much guarantees a flush perpendicular cut to connect the objective cell and focuser backplate components.