WEAPONS FOUNDATION MACHINING PROBLEMS

[DONKUMPUNEN]

I WORK IN NAVY QA IN SHIP BUILDING.THE SHIP YARD WHERE I WORK HAS A CONTINUOUS PROBLEM WITH MACHINING FOUNDATIONS FOR
ANTENNAS ON THE 05 LEVEL.THEIR BORING BAR IS NOT BIG ENOUGH TO COVER THE WHOLE FOUNDATION IN ONE SWEEP SO THEY TAKE A HALF CUT AND RESET UP,LEVEL CHECKS,ETC.HOWEVER FREQUENTLY THE FOUNDATION HAS TO BE REMACHINED BECAUSE IT IS NOT WITHIN
THE FLATNESS PITCH AND ROLL REQUIREMENTS.
ARE THERE SOME WEB SITES OUT THERE THAT SHOW IN DETAIL THE USE OF OPTICAL EQUIPMENT AND SET UP OF THE BORING BAR,
ETC.I KNOW ONE TIME THEY CALLED IN IN-PLACE MACHINING OUT OF
MILWAUKEE WISCONSIN TO DO THE JOB.
DON KUMPUNEN

 

[nbucska]

OMITTINGTHESPACESBESIDESTHELOWERCASEMAKESITMUCHHARDERTOREADIFTHISISYOURPURPOSE.

<nbucska@pcperipherals.com>

 

[ubrales]

Find a machine shop that has a boring mill that can handle the entire machining in one chucking. It is virtually impossible to get a good flat machine base in multiple chuckings - this is beacause the bed and the machining spindle will move ever so slightly during the cut. Also, it is important to cut in the same direction, for the same reasons. The part must not overhang the bed, and the cut must be made at a high feed rate thus yeilding a medium finish (128 microinch) instead of a fine finish.

If a greater flatness is desired, then I suggest blueing and hand scraping. This will give you a flatness of 3 microns per meter or better if desired. Of course, the cost goes up exponentially.

 

[nbucska]

DON:
Have you found a solution? if not, could you
send me some more detailed description ?


<nbucska@pcperipherals DOT com> subj: eng-tips