Instructions for Wire EDM Machining of Somma Throwaway Quick Change Inserts 1/8" Thick for Use in RQCMS-2 and RQCMS-3 Shave Tool Holders

ALL RQC STYLE SHAVE TOOL HOLDERS ARE DESIGNED FOR A 0 DEGREE FRONT CLEARANCE ANGLE AND 0 DEGREE TOP RAKE, THEREFORE, INSERTS MUST BE SET AT 0 DEGREES IN RELATION TO THE TOP AND BOTTOM FACES WHEN BEING EDM MACHINED AND STEP CORRECTIONS CALCULATED ACCORDINGLY.

ALSO INSERTS MUST BE A PARALLELOGRAM FORM, THEREFORE, BACK SURFACE MUST ALSO BE AT 0 DEGREES PARALLEL TO FORMED FACE.

INSERTS ARE OVERSIZE ON LENGTH AND WIDTH TO ALLOW FOR EDM WIRE THICKNESS AND ARE RECESSED ON BACK END FOR MOUNTING IN THE GRINDING FIXTURE SO THAT BACK EDGES CAN BE MACHINED AT THE SAME TIME AS FORMED SURFACE WITHOUT REMOVING FROM FIXTURE.

FIXTURE IS SUPPLIED WITH TWO WEDGE CLAMPS TO HOLD 8 INSERTS.

IMPORTANT: BACKUP ANVIL SHOULD BE EDMed SEPARATELY USING SPACERS TO HOLD IT IN FIXTURE.  ALSO CUTTING CONDITIONS SHOULD BE CHANGED SO AS TO LEAVE APPROXIMATELY .005" CLEARANCE ON ALL SIDE CUTTING SURFACES TO PREVENT SIDE RUBBING ON PART.

INSERTS SHOULD BE CAREFULLY MOUNTED IN FIXTURE AND TIGHTENED SECURELY WITH CLAMP SCREW.  BE CERTAIN THAT INSERTS ARE FULLY SEATED IN BOTTOM BASE OF FIXTURE.  THIS IS IMPORTANT BECAUSE IF FACE ANGLES ARE NOT EXACTLY 0 DEGREES, THERE MAY BE DIAMETRAL DIFFERENCE ERRORS IN THE WORK PIECE.

ALSO, INSERTS SHOULD BE IN ALIGNMENT WITH EACH OTHER AND CLEARANCE ANGLE CUTOUT IN INSERT SHOULD BE CENTERED ON FIXTURE WITH EQUAL SPACE ON BOTH SIDES OF FIXTURE BODY.

WHEN WIRE EDMing, WE RECOMMEND MACHINING ALL THE WAY AROUND THE FORM STARTING ON THE LEFT SIDE IN THE SPACE BETWEEN THE FIXTURE AND THE RECESS IN THE INSERT AND ENDING IN THE SPACE ON THE OPPOSITE SIDE (SEE SAMPLE PRINT ATTACHED).  THIS GROOVE PREVENTS OUTER SHELL FROM BREAKING OFF AND JAMMING WIRE.

FOR RQCMS-2 HOLDERS:

IN ORDER TO SIMPLIFY ADJUSTMENT OF THE INSERT SLIDE WHEN CHANGING OVER FROM JOB TO JOB, HOLDERS ARE DESIGNED TO THAT A 1.125" LONG INSERT WILL CUT TO 1/8" DIAMETER (.125" BASE DIAMETER).  THEREFORE, ALL INSERTS SHOULD BE DESIGNED USING A .125" AS THE BASE DIAMETER.  THIS WILL CAUSE THE INSERT TO BE CORRESPONDINGLY SHORTER FOR ALL OTHER DIAMETERS, OR SLIGHTLY LONGER IF FORMING A DIAMETER SMALLER THAN A .125".

FOR RQCMS-3 HOLDER:

THIS HOLDER IS DESIGNED SO THAT A 1.125" LONG INSERT WILL CUT .500" DIAMETER ON THE PART.  THEREFORE, ALL INSERTS SHOULD BE DESIGNED USING .500" AS THE BASE DIAMETER.  SEE SAMPLE INSERT DESIGN.

ENCLOSED ARE MASTER INSERT DESIGN SHEETS FOR 1-3/4" WIDE INSERTS.  ADDITIONAL SHEETS ARE AVAILABLE UPON REQUEST.

SEE BELOW FOR ANOTHER DIAGRAM