Area Scheduler Valve for Inlet Spike

This valve moves the spike of a ram jet in or out to adjust the shock wave.

    This part had some close diametrical and concentric tolerances that needed to be held.  First we roughed the ID using a step drill and finished the ID profile with a 2-D tracer, leaving stock on the 3 close diameter bores.  The part was then heat treated for stability.  We then finished the OD to print, again using a tracer.   Holding on the OD we then ground the 2 large IDs holding a diametrical tolerance of   less than .0002.  Now we faced another challenge.  We were required to hold concentric to within .0002 the two large diameters to the small ID diameter.   However, the question was how to hold the part.  An expanding spud would not consistently hold the tolerance.  Bob came up with the idea of making a very close fitting solid spud.  The part was then held on by lanolin.  For the last step, the part was lapped to a diametrical tolerance of .0005 in a temperature controlled room.   All of the parts were made and fit at Grindley.