|SP2479 Aux Dome Report|
Progress has slowed. Upon receipt of the aux dome cover blank, it was decided to practice machining with a piece of scrap plate. A suitable plate was prepared and a number of small holes bored.
Biggest concern is threading holes for the three inch safeties. Finished holes will be approximately four inches in diameter with an 8 pitch thread. CRTC's only machine capable of this work is the Leblond lathe located in the trolley barn.
This machine has not been used in a number of years. It required cleanup and lubrication. During this process several deficiencies were noted. A piece of the taper attachment was missing and was constructed. The biggest concern is wear in machine parts. It was noted that there was a near half turn revolution of the crossfeed handle. The lead screw was removed and inspect. Both the lead screw and nut are heavily worn. The compound feed is also very loose.
Obviously destroying a four hundred dollar part is not on the task list. Currnet condition of the lathe is a major concern but we are not ready to give up. Next Saturday the test plate will be mounted. An attempt at boring and threading of the first large hole will begin. Upon completion a look at direction will be taken.
Weeks of cleaning, fixing and understanding the trolley barn's Leblond lathe has paid off! Yesterday, 2479's master mechanic tapered and threaded a four inch hole in the test plate! A cap was set into the hole to prove the work. With the first hole complete, the test plate was repositioned. This hole will also be tapered and threaded for added experience.
In image, note plate off-set from chuck center. The lowest rotational speed of the chuck was being used. This plate weighs less than half that of the new cover. The task is looking much more do able on this lathe but there is still a question as to the lathe being able to turn the heavy part off center.
Saturday work crews continue to be very small. The remainder of the crew has been working at site appearance. Rain followed by sunny, warm temperatures have kicked grass and weed growth into high gear. Keeping the storage areas clear of tall weeds is difficult and time consuming.