Good morning people. I have some need of your skills. I have attached here a sketch showing a cross section of a part that resembles an inverted dog bowl with a radial cut feature (all around the centerline) inside on the wall. I can't snipit the actual CAD model shot as the part is military in nature. My issue is this. I'm having a "locked horns drag out" with a government inspector who does not care how I measured the feature I am going to describe. On the print the callout is for a basic diameter on the curved surface (relative to R basic) and they call out the Z depth of that basic circle as +/ .01 from the top lip. Well, using the CAD I went the other way and went to the called Z depth nominal and measured polar points at that depth and using the CAD model, calculated the diametric tolerance parameters allowed over the +/ .01 Z depth tolerance. Kind of the same technique used in measuring CAM lobes. The points on the curve are toleranced and the location of the points of tangency are basic. Anyway, the government guys are anal and want it backwards. So, the question: the best way to "find" that basic Radial point on the curve and give a readout of it's Z parameter based on where it exists within +/ .01. I think there is a circular construction feature based on creating a basic circular diameter of a scan set which I can do as I use SM25 scanning head probes but I'm unfamiliar with the technique. If you see an easier methodology I'm all ears. Thanks! Sketch1.pdf
Circular Construct Issue
Collapse
X

Maybe using "fixed rad" here could be the solution ?
I didn't look at the right radius.
I would measure the radius R1 as a circle, then create a generic plane X=R basic, I=1, and create a pierce point between the circle and the plane, then copy / paste with pattern and create a circle from all pierce points if necessary, and dimension them.Last edited by JEFMAN; 05312019, 10:44 AM.

Looks like they're basically asking for the Z value of the radius center. As JEFMAN said, use FIXED_RAD, it's the only possible way you'll get a repeatable center.
Code:CIR1 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR THEO/<16.5,0,3.9>,<1,0,0>,17.4,0 ACTL/<16.5,0,3.9>,<1,0,0>,17.4,0 TARG/<16.5,0,3.9>,<1,0,0> START ANG=0,END ANG=360 ANGLE VEC=<1,0,0> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=7,DEPTH=5,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=3,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=NO CIR2 =FEAT/CIRCLE,CARTESIAN,IN,FIXED_RAD,YES THEO/<21.5,0,3.9>,<0,0,1>,17.4 ACTL/<21.5,0,3.9>,<1,0,0>,17.4 CONSTR/CIRCLE,BF,2D,CIR1.HIT[1..CIR1.NUMHITS],, OUTLIER_REMOVAL/OFF,3 FILTER/OFF,UPR=0
Code:COMMENT/OPER,NO,FULL SCREEN=NO,AUTOCONTINUE=NO, Assume they want the Z value at a basic diameter of Ø40 ORIGIN_POINT=FEAT/POINT,CARTESIAN,NO THEO/<0,0,0>,<0,0,1> ACTL/<0,0,0>,<0,0,1> CONSTR/POINT,ORIGIN OFFSET_PT1 =FEAT/POINT,CARTESIAN,NO THEO/<20,0,0>,<0,0,1> ACTL/<20,0,0>,<0,0,1> CONSTR/POINT,OFFSET,ORIGIN_POINT,20,0,0 OFFSET_PT2 =FEAT/POINT,CARTESIAN,NO THEO/<0,20,0>,<0,0,1> ACTL/<0,20,0>,<0,0,1> CONSTR/POINT,OFFSET,ORIGIN_POINT,0,20,0 OFFSET_PT3 =FEAT/POINT,CARTESIAN,NO THEO/<20,0,0>,<0,0,1> ACTL/<20,0,0>,<0,0,1> CONSTR/POINT,OFFSET,ORIGIN_POINT,20,0,0 OFFSET_PT4 =FEAT/POINT,CARTESIAN,NO THEO/<0,20,0>,<0,0,1> ACTL/<0,20,0>,<0,0,1> CONSTR/POINT,OFFSET,ORIGIN_POINT,0,20,0 PART_ZAXIS =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<0,0,0.5>,<0,0,1> ACTL/<0,0,0.5>,<0,0,1> CONSTR/LINE,ALIGN,1,ZPLUS CIR2 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,FIXED_RAD THEO/<16.5,0,3.9>,<0,1,0>,8 ACTL/<16.5,0,3.9>,<0,1,0>,8 TARG/<16.5,0,3.9>,<0,1,0> START ANG=0,END ANG=360 ANGLE VEC=<0,0,1> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=7,DEPTH=5,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=3,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=NO CIR3 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,FIXED_RAD THEO/<0,16.5,3.9>,<1,0,0>,8 ACTL/<0,16.5,3.9>,<1,0,0>,8 TARG/<0,16.5,3.9>,<1,0,0> START ANG=0,END ANG=360 ANGLE VEC=<0,0,1> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=7,DEPTH=5,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=3,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=NO CIR4 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,FIXED_RAD THEO/<16.5,0,3.9>,<0,1,0>,8 ACTL/<16.5,0,3.9>,<0,1,0>,8 TARG/<16.5,0,3.9>,<0,1,0> START ANG=0,END ANG=360 ANGLE VEC=<0,0,1> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=7,DEPTH=5,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=3,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=NO CIR5 =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,FIXED_RAD THEO/<0,16.5,3.9>,<1,0,0>,8 ACTL/<0,16.5,3.9>,<1,0,0>,8 TARG/<0,16.5,3.9>,<1,0,0> START ANG=0,END ANG=360 ANGLE VEC=<0,0,1> DIRECTION=CCW SHOW FEATURE PARAMETERS=NO SHOW CONTACT PARAMETERS=YES NUMHITS=7,DEPTH=5,PITCH=0 SAMPLE METHOD=SAMPLE_HITS SAMPLE HITS=3,SPACER=0 AVOIDANCE MOVE=NO,DISTANCE=10 FIND HOLE=DISABLED,ONERROR=NO,READ POS=NO SHOW HITS=NO LIN2 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<20,0,1>,<0,0,1> ACTL/<20,0,1>,<0,0,1> CONSTR/LINE,PLTO,PART_ZAXIS,OFFSET_PT1,1 LIN3 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<0,20,1>,<0,0,1> ACTL/<0,20,1>,<0,0,1> CONSTR/LINE,PLTO,PART_ZAXIS,OFFSET_PT2,1 LIN4 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<20,0,1>,<0,0,1> ACTL/<20,0,1>,<0,0,1> CONSTR/LINE,PLTO,PART_ZAXIS,OFFSET_PT3,1 LIN5 =FEAT/LINE,CARTESIAN,UNBOUNDED,NO THEO/<0,20,1>,<0,0,1> ACTL/<0,20,1>,<0,0,1> CONSTR/LINE,PLTO,PART_ZAXIS,OFFSET_PT4,1 PNT2 =FEAT/POINT,CARTESIAN,NO THEO/<20,0,5.836>,<0,0,1> ACTL/<20,0,5.836>,<0,0,1> CONSTR/POINT,PIERCE,LIN2,CIR2 PNT3 =FEAT/POINT,CARTESIAN,NO THEO/<0,20,5.836>,<0,0,1> ACTL/<0,20,5.836>,<0,0,1> CONSTR/POINT,PIERCE,LIN3,CIR3 PNT4 =FEAT/POINT,CARTESIAN,NO THEO/<20,0,5.836>,<0,0,1> ACTL/<20,0,5.836>,<0,0,1> CONSTR/POINT,PIERCE,LIN4,CIR4 PNT5 =FEAT/POINT,CARTESIAN,NO THEO/<0,20,5.836>,<0,0,1> ACTL/<0,20,5.836>,<0,0,1> CONSTR/POINT,PIERCE,LIN5,CIR5 THE_ANSWER =FEAT/CIRCLE,CARTESIAN,IN,LEAST_SQR,NO THEO/<0,0,5.836>,<0,0,1>,40 ACTL/<0,0,5.836>,<0,0,1>,40 CONSTR/CIRCLE,BF,2D,PNT2,PNT3,PNT4,PNT5,, OUTLIER_REMOVAL/OFF,3 FILTER/OFF,UPR=0
Comment
Related Topics
Collapse

by BrandnewHey Everybody,
Wondered if you guys could help me out increase my learning curve. i have a circular object in which i need to measure...
Channel: PCDMIS for CMMs
02212009, 02:12 PM 

by John KuglerIs it possible to construct an intersection point between a generic circle and a measured line?? I have a print that has an intersection point between...

Channel: PCDMIS for CMMs
01112007, 04:13 PM 

I have a dimension that consistently shows out of tolerance, but the supplier has it consistently in tolerance. They are using BASIC for the Y and Z,...

Channel: PCDMIS for CMMs
02042015, 12:26 PM 

by aj48198I have a question that I hope someone here can help me figure out. I have a twist driver that has 6 radii around it, what I need is the diameter of the...

Channel: PCDMIS for CMMs
01272015, 02:53 PM 

by cmmguyI have been trying to make circluar moves work on plane measurements but have run into a stumbling block. I am 80% to having this figure out but am stuck...

Channel: PCDMIS for CMMs
03152007, 02:17 PM 
Comment