Dimension from theoretical pin

Question

Hi i have this part and i need to measure the 50.1 dimension. 
 Im not sure how to go about to construct the &Oslash;8 pins where the tangent the guide rail. 
 Can i measure this in cmm or do i need to build a checking fixture? ty you all

markus lundkvist · Accepted Answer

and this is my first time here 
 hi guys

Neil Challinor · Answer

Assuming your section A-A view is looking down the Y axis, you would need to measure the two planar faces and then intersect them with a generic plane (YPLUS vector) to give you two lines. You would then need to construct another two generic lines, one at X-12 and one at X+12. You can then create two circles, tangential to the lines as shown below... PLN1 =FEAT/CONTACT/PLANE/DEFAULT,CARTESIAN,OUTLINE,LEAST_SQR THEO/<-5.172,0,-2.828>,<-0.7071068,0,0.7071068> ACTL/<-5.172,0,-2.828>,<-0.7071068,0,0.7071068> TARG/<-5.172,0,-2.828>,<-0.7071068,0,0.7071068> ANGLE VEC=<0.7071068,0,-0.7071068>,SQUARE SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=2,NUMROWS=2 SPACER=3 AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=10,DISTANCE AFTER=10,DIRECTION=ALONG FEATURE VECTOR USE BOUNDARY OFFSET=NO SHOW HITS=NO PLN2 =FEAT/CONTACT/PLANE/DEFAULT,CARTESIAN,OUTLINE,LEAST_SQR THEO/<5.172,0,-2.828>,<0.7071068,0,0.7071068> ACTL/<5.172,0,-2.828>,<0.7071068,0,0.7071068> TARG/<5.172,0,-2.828>,<0.7071068,0,0.7071068> ANGLE VEC=<0.7071068,0,-0.7071068>,SQUARE SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=2,NUMROWS=2 SPACER=2 AVOIDANCE MOVE=BOTH,DISTANCE BEFORE=10,DISTANCE AFTER=10,DIRECTION=ALONG FEATURE VECTOR USE BOUNDARY OFFSET=NO SHOW HITS=NO F1 =GENERIC/LINE,DEPENDENT,CARTESIAN,$ NOM/XYZ,<-12,0,0>,$ MEAS/XYZ,<-12,0,0>,$ NOM/IJK,<0,0,1>,$ MEAS/IJK,<0,0,1>,$ DISTANCE/10,10 F2 =GENERIC/LINE,DEPENDENT,CARTESIAN,$ NOM/XYZ,<12,0,0>,$ MEAS/XYZ,<12,0,0>,$ NOM/IJK,<0,0,-1>,$ MEAS/IJK,<0,0,-1>,$ DISTANCE/10,10 F3 =GENERIC/PLANE,DEPENDENT,CARTESIAN,$ NOM/XYZ,<0,0,0>,$ MEAS/XYZ,<0,0,0>,$ NOM/IJK,<0,1,0>,$ MEAS/IJK,<0,1,0> LIN1 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<-3.172,0,-0.828>,<-0.7071068,0,-0.7071068> ACTL/<-3.172,0,-0.828>,<-0.7071068,0,-0.7071068> CONSTR/LINE,INTOF,PLN1,F3 LIN2 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<3.172,0,-0.828>,<-0.7071068,0,0.7071068> ACTL/<3.172,0,-0.828>,<-0.7071068,0,0.7071068> CONSTR/LINE,INTOF,PLN2,F3 WORKPLANE/YPLUS CIR1 =FEAT/CIRCLE,CARTESIAN,OUT,NO THEO/<-8,0,0>,<0,1,0>,8 ACTL/<-8,0,0>,<0,1,0>,8 CONSTR/CIRCLE,TANLINES,F1,LIN1, CIR2 =FEAT/CIRCLE,CARTESIAN,OUT,NO THEO/<8,0,0>,<0,1,0>,8 ACTL/<8,0,0>,<0,1,0>,8 CONSTR/CIRCLE,TANLINES,F2,LIN2,