Runout Experts needed...

[Ray Harvey]

I have 2 circles that I scanned. I drew a line between the 2 and that is being used as my Datum. Can runout be measured using a line drawn between to circles? I was told that using cones makes it nearly impossible to get good runout data.

[louisd]

Your question is very short-worded, so we can only imply a few conditions...

I have 2 circles that I scanned. I drew a line between the 2 and that is being used as my Datum.

Are these two circles for your datum coaxial?

Can runout be measured using a line drawn between to circles?

No. Runout is a surface measurement, not an axis measurement. You would be measuring concentricity if you judge only the center-line.

I was told that using cones makes it nearly impossible to get good runout data.

What does this have to do with cones?

[Douglas]

if these circles are 2 locations on a shaft for example, I construct a line using 2 circles to define the part axis then use it as a datum to check concentricity or runout of other features against, I think this is what he means

[louisd]

yes you can use two circles to level to, for establishing a datum axis.
Measurement of runout is not relative to the axis line however, it is measured as a circumferential "total indicator readout" of the part surface.

[Douglas]

yes the total variation of the surface while rotated about that axis line, the axis is just the datum not the runout itself. Move the axis and the runout value changes though so it is not really as independent of center point as a circularity measurement is, but yes the error is on the surface in both cases

[Schlag]

• 
  
  " Measurement of runout is not relative to the axis line however, it is measured as a circumferential "total indicator readout" of the part surface".
  
  Isnt this exactly what runout is ? The surface in relation to an AXIS / DATUM ?

[Schlag]

Page 180 of Y14.5-2009
SECTION 9-2
Runout is the tol. used to control the function relationship of 1 or more features to a datum axis established from a datum feature.

[louisd]

Shlag, the question posed is worded rather oddly. "Can runout be measured using a line drawn between to circles?"
The answer is No. Runout cannot be MEASURED using a line. Never ever. Runout must be measured as we've both clarified.

DATUM ALIGNMENT can be established with a line drawn between two circles, then runout can be measured circumferentially, relative to that line...
--you can't MEASURE (aka quantify variation numerically) runout with an axis line.

[DAN_M]

Yes. I do this a lot. But not through just two circles.

I have many turned parts where -A- is an outside diameter, -B- is a different sized outside diameter, and there is GD&T all over my print that says '"Runout of a certain diameter A-B".

I will measure three individual autocircles on -A-. Three individual autocircles on -B-. Put a point at the center of each circle. Construct a 3D line through the six points. Then..Insert an alignment....Level to Line A-B..Translate X and Y to Line A-B, Translate Z to a plane/point where I want it.

If you want to see some sample code LMK.

[Ray Harvey]

Sure. I will try this out and see if this works. If you have some samples I would appreciate it. That actually makes a lot of sense to do it that way...

Thanks….

[DAN_M]

COMMENT/OPER,NO,FULL SCREEN=NO,AUTO-CONTINUE=NO,
            Once you press OKAY to this message....

            Measure a circle (4 hits) in the side hole
            COMMENT/OPER,NO,FULL SCREEN=NO,AUTO-CONTINUE=NO,
            Press OKAY for CNC Measurement
            MODE/MANUAL
            WORKPLANE/XPLUS
CIR_3PLACE_MANUAL=FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<0.55,-0.486,-3.38>,<1,0,0>,0.2475
            ACTL/<0.55,-0.486,-3.38>,<1,0,0>,0.2475
            TARG/<0.55,-0.486,-3.38>,<1,0,0>
            START ANG=0,END ANG=360
            ANGLE VEC=<0,0,-1>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MODE/DCC
CYL_3PLACE_CNC=FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<0.585,-0.486,-3.38>,<1,0,0>,0.2475,0.075
            ACTL/<0.585,-0.486,-3.38>,<1,0,0>,0.2475,0.075
            TARG/<0.585,CIR_3PLACE_MANUAL.Y+0,CIR_3PLACE_MANUAL.Z+0>,<1,0,0>
            START ANG=0,END ANG=360
            ANGLE VEC=<0,0,-1>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            WORKPLANE/ZPLUS
A3         =ALIGNMENT/START,RECALL:STARTUP,LIST=YES
              ALIGNMENT/LEVEL,ZPLUS,PLN_Z1
              ALIGNMENT/ROTATE,XPLUS,TO,CYL_3PLACE_CNC,ABOUT,ZPLUS
              ALIGNMENT/TRANS,XAXIS,CIR_XY2
              ALIGNMENT/TRANS,YAXIS,CIR_XY2
              ALIGNMENT/TRANS,ZAXIS,PLN_Z1
            ALIGNMENT/END
            MOVE/POINT,NORMAL,<1.5,-0.486,-3.38>
            MOVE/POINT,NORMAL,<1.5,-0.486,4>
            TIP/T1A45B180, SHANKIJK=0, -0.7071, 0.7071, ANGLE=180
RADH1      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-0.875>,<0,0,1>,2.3781,0
            ACTL/<0,0,-0.875>,<0,0,1>,2.3781,0
            TARG/<0,0,-0.875>,<0,0,1>
            START ANG=-2.5,END ANG=182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADH2      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-1.1>,<0,0,1>,2.3781,0
            ACTL/<0,0,-1.1>,<0,0,1>,2.3781,0
            TARG/<0,0,-1.1>,<0,0,1>
            START ANG=182.5,END ANG=-2.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0.25,0,0>
RADG1      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-3.8>,<0,0,1>,2.4027,0
            ACTL/<0,0,-3.8>,<0,0,1>,2.4027,0
            TARG/<0,0,-3.8>,<0,0,1>
            START ANG=-2.5,END ANG=182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADG2      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-4.5>,<0,0,1>,2.4027,0
            ACTL/<0,0,-4.5>,<0,0,1>,2.4027,0
            TARG/<0,0,-4.5>,<0,0,1>
            START ANG=182.5,END ANG=-2.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADG3      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-5.2>,<0,0,1>,2.4027,0
            ACTL/<0,0,-5.2>,<0,0,1>,2.4027,0
            TARG/<0,0,-5.2>,<0,0,1>
            START ANG=-2.5,END ANG=182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0,-0.55,0>
PNTF1      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<-1.1172,-0.645,-5.34>,<0,0,1>
            ACTL/<-1.1172,-0.645,-5.34>,<0,0,1>
            TARG/<-1.1172,-0.645,-5.34>,<0,0,1>
            SNAP=NO
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0,-0.645,0>
PNTF2      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<0,-1.29,-5.34>,<0,0,1>
            ACTL/<0,-1.29,-5.34>,<0,0,1>
            TARG/<0,-1.29,-5.34>,<0,0,1>
            SNAP=NO
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<1.1172,0,0>
PNTF3      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<1.1172,-0.645,-5.34>,<0,0,1>
            ACTL/<1.1172,-0.645,-5.34>,<0,0,1>
            TARG/<1.1172,-0.645,-5.34>,<0,0,1>
            SNAP=NO
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/POINT,NORMAL,<PNTF3.X+0.1,PNTF3.Y-0.1,1>
            TIP/T1A45B0, SHANKIJK=0, 0.7071, 0.7071, ANGLE=0
RADH3      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-0.875>,<0,0,1>,2.3781,0
            ACTL/<0,0,-0.875>,<0,0,1>,2.3781,0
            TARG/<0,0,-0.875>,<0,0,1>
            START ANG=2.5,END ANG=-182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADH4      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-1.1>,<0,0,1>,2.3781,0
            ACTL/<0,0,-1.1>,<0,0,1>,2.3781,0
            TARG/<0,0,-1.1>,<0,0,1>
            START ANG=177.5,END ANG=362.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0.25,0,0>
RADG4      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-3.8>,<0,0,1>,2.4027,0
            ACTL/<0,0,-3.8>,<0,0,1>,2.4027,0
            TARG/<0,0,-3.8>,<0,0,1>
            START ANG=2.5,END ANG=-182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADG5      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-4.5>,<0,0,1>,2.4027,0
            ACTL/<0,0,-4.5>,<0,0,1>,2.4027,0
            TARG/<0,0,-4.5>,<0,0,1>
            START ANG=177.5,END ANG=362.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
RADG6      =FEAT/CONTACT/CIRCLE/DEFAULT,CARTESIAN,OUT,LEAST_SQR
            THEO/<0,0,-5.2>,<0,0,1>,2.4027,0
            ACTL/<0,0,-5.2>,<0,0,1>,2.4027,0
            TARG/<0,0,-5.2>,<0,0,1>
            START ANG=2.5,END ANG=-182.5
            ANGLE VEC=<1,0,0>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0,0.55,0>
PNTF4      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<-1.1172,0.645,-5.34>,<0,0,1>
            ACTL/<-1.1172,0.645,-5.34>,<0,0,1>
            TARG/<-1.1172,0.645,-5.34>,<0,0,1>
            SNAP=NO
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<0,0.645,0>
PNTF5      =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<0,1.29,-5.34>,<0,0,1>
            ACTL/<0,1.29,-5.34>,<0,0,1>
            TARG/<0,1.29,-5.34>,<0,0,1>
            SNAP=NO
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
            MOVE/INCREMENT,<1.1172,0,0>

[DAN_M]

pntf6      =feat/contact/vector point/default,cartesian
            theo/<1.1172,0.645,-5.34>,<0,0,1>
            actl/<1.1172,0.645,-5.34>,<0,0,1>
            targ/<1.1172,0.645,-5.34>,<0,0,1>
            snap=no
            show feature parameters=no
            show contact parameters=no
pln_f      =feat/plane,cartesian,triangle,no,least_sqr
            theo/<0,0,-5.34>,<0,0,1>
            actl/<0,0,-5.34>,<0,0,1>
            constr/plane,bf,pntf1,pntf2,pntf3,pntf4,pntf5,pntf6,,
            outlier_removal/off,3
            filter/off,wavelength=0
scn1       =feat/set,cartesian
            theo/<0,0,-5.2>,<0,0,1>
            actl/<0,0,-5.2>,<0,0,1>
            constr/set,basic,radg3.hit[1..5],radg6.hit[1..5],,
cir_g_bot  =feat/circle,cartesian,out,least_sqr,no
            theo/<0,0,-5.2>,<0,0,1>,2.4027
            actl/<0,0,-5.2>,<0,0,1>,2.4027
            constr/circle,bf,2d,scn1,,
            outlier_removal/off,3
            filter/off,upr=0
pnt_g_bot  =feat/point,cartesian,no
            theo/<0,0,-5.2>,<0,0,1>
            actl/<0,0,-5.2>,<0,0,1>
            constr/point,cast,cir_g_bot
scn4       =feat/set,cartesian
            theo/<0,0,-4.5>,<0,0,1>
            actl/<0,0,-4.5>,<0,0,1>
            constr/set,basic,radg2.hit[1..5],radg5.hit[1..5],,
cir_g_ctr  =feat/circle,cartesian,out,least_sqr,no
            theo/<0,0,-4.5>,<0,0,1>,2.4027
            actl/<0,0,-4.5>,<0,0,1>,2.4027
            constr/circle,bf,2d,scn4,,
            outlier_removal/off,3
            filter/off,upr=0
pnt_g_ctr  =feat/point,cartesian,no
            theo/<0,0,-4.5>,<0,0,1>
            actl/<0,0,-4.5>,<0,0,1>
            constr/point,cast,cir_g_ctr
scn7       =feat/set,cartesian
            theo/<0,0,-3.8>,<0,0,1>
            actl/<0,0,-3.8>,<0,0,1>
            constr/set,basic,radg1.hit[1..5],radg4.hit[1..5],,
cir_g_top  =feat/circle,cartesian,out,least_sqr,no
            theo/<0,0,-3.8>,<0,0,1>,2.4027
            actl/<0,0,-3.8>,<0,0,1>,2.4027
            constr/circle,bf,2d,scn7,,
            outlier_removal/off,3
            filter/off,upr=0
pnt_g_top  =feat/point,cartesian,no
            theo/<0,0,-3.8>,<0,0,1>
            actl/<0,0,-3.8>,<0,0,1>
            constr/point,cast,cir_g_top
cyl_g      =feat/cylinder,cartesian,out,least_sqr,no
            theo/<0,0,-4.5>,<0,0,1>,2.4027,1.4
            actl/<0,0,-4.5>,<0,0,1>,2.4027,1.4
            constr/cylinder,bf,cir_g_bot,cir_g_ctr,cir_g_top,,
scn10      =feat/set,cartesian
            theo/<0,0,-1.1>,<0,0,1>
            actl/<0,0,-1.1>,<0,0,1>
            constr/set,basic,radh2.hit[1..5],radh4.hit[1..5],,
cir_h_bot  =feat/circle,cartesian,out,least_sqr,no
            theo/<0,0,-1.1>,<0,0,1>,2.3781
            actl/<0,0,-1.1>,<0,0,1>,2.3781
            constr/circle,bf,2d,scn10,,
            outlier_removal/off,3
            filter/off,upr=0
pnt_h_bot  =feat/point,cartesian,no
            theo/<0,0,-1.1>,<0,0,1>
            actl/<0,0,-1.1>,<0,0,1>
            constr/point,cast,cir_h_bot
scn13      =feat/set,cartesian
            theo/<0,0,-0.875>,<0,0,1>
            actl/<0,0,-0.875>,<0,0,1>
            constr/set,basic,radh1.hit[1..5],radh3.hit[1..5],,
cir_h_top  =feat/circle,cartesian,out,least_sqr,no
            theo/<0,0,-0.875>,<0,0,1>,2.3781
            actl/<0,0,-0.875>,<0,0,1>,2.3781
            constr/circle,bf,2d,scn13,,
            outlier_removal/off,3
            filter/off,upr=0
pnt_h_top  =feat/point,cartesian,no
            theo/<0,0,-0.875>,<0,0,1>
            actl/<0,0,-0.875>,<0,0,1>
            constr/point,cast,cir_h_top
cyl_h      =feat/cylinder,cartesian,out,least_sqr,no
            theo/<0,0,-0.9875>,<0,0,1>,2.3781,0.225
            actl/<0,0,-0.9875>,<0,0,1>,2.3781,0.225
            constr/cylinder,bf,cir_h_bot,cir_h_top,,
            workplane/yminus
lin_gh     =feat/line,cartesian,unbounded,no
            theo/<0,0,-5.2>,<0,0,1>
            actl/<0,0,-5.2>,<0,0,1>
            constr/line,bf,3d,pnt_g_bot,pnt_g_ctr,pnt_g_top,pnt_h_bot,pnt_h_top,,
            outlier_removal/off,3
            filter/off,wavelength=0
            workplane/zplus
a4         =alignment/start,recall:startup,list=yes
              alignment/level,zplus,pln_f
              alignment/rotate,xplus,to,cyl_3place_cnc,about,zplus
              alignment/trans,xaxis,lin_gh
              alignment/trans,yaxis,lin_gh
              alignment/trans,zaxis,pln_f
            alignment/end
a5         =alignment/start,recall:startup,list=yes
              alignment/level,zplus,lin_gh
              alignment/trans,xaxis,lin_gh
              alignment/trans,yaxis,lin_gh
              alignment/trans,zaxis,pln_f
            alignment/end

[DAN_M]

Capture.PNG
My part was approx 1.5feet tall and 3" in dia..had a bunch of runouts that were "G-H" on my print (the blue surfaces).
Datum -H- was kind of small so I only did two circles on it. But you get the idea. Ray Harvey

[Douglas]

This is pretty much what I've done on several parts and I like it, our in house engineering drawings don't use much GDT so it is up to me to define datums as I see functionally important... and I report the form deviations I want to, but it all saves our *** when assemblies fail and we need to defend our parts. Often the root cause is never really determined but those with the least inspection data are on the hook. Those 2 datum surfaces on a shaft will often be the bearing journals for example and the rest of the shaft can be checked for runout functionally the way it will be restrained by the bearings in service.

[Ray Harvey]

Sorry for the late response, I was unavailable to respond " family emergency". I will try this and see if I can get this to work... DAN_M