hexagon logo
Register Sign in
  • Replies 18 replies
  • Subscribers 222 subscribers
  • Views 450 views
  • Users 0 members are here
Options
Related

PC-DMIS giving bad results

Mflores2324
Need help!! Not sure why PC-DMIS keeps giving me bad results. I have created different alignments, different hits, different workplanes and views but PC-DMIS still gives me wrong numbers. Any suggestions on what is going on?

On the blueprint I have provided the Dimensions I need and the results I am getting.
I am currently running on PC DMIS 2021.1
CMM SF 7.10.7

  • Lets see the actual print ? Any of those holes threaded ?
  • Your cylinder 3 actuals are concerning. The deviations are quite high. Something looks to be off between your rotational line1 and the cylinder3 centerline. Throw some more dimensions in there and do some more manual checks to narrow down the disagreement between your two methods. ie. angle between cylinder 3 and your planes, angle&position between cylinder3 and line1, distances of the pierce points to the holes&line1.

    Since your final result is a 2d distance, chances of error tying back to how the part is aligned is high. I would also measure the cylinder3, level and align to it, then remeasure it to be certain no vector issues if your 2 holes and planes happen to be off.
  • in reply to Schlag
    No threaded holes. And I will upload the drawing below.
  • Easier to read 

    =alignment/start,recall:use_part_setup,list=yes
alignment/end
mode/manual
format/text,options,id,headings,symbols, ;nom,tol,meas,maxmin,dev,devang,outtol
movespeed/ 300
prehit/0.125
retract/0.125
touchspeed/ 3.5
loadprobe/tool_2
tip/t1a0b0, shankijk=0, 0, 1, angle=0
startpoint =feat/point,cartesian
theo/<0,0,0>,<0,0,1>
actl/<9.5192,14.6362,-23.982>,<0,0,1>
readpoint/
a1 =alignment/start,recall:startup,list=yes
alignment/trans,xaxis,startpoint
alignment/trans,yaxis,startpoint
alignment/trans,zaxis,startpoint
alignment/end
mode/dcc
move/increment,<0,0,0.3>
point2 =feat/contact/vector point/default,cartesian
theo/<-0.1926,-0.4883,0.03>,<0,0,1>
actl/<-0.1926,-0.4883,0.025>,<0,0,1>
targ/<-0.1926,-0.4883,0.03>,<0,0,1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point3 =feat/contact/vector point/default,cartesian
theo/<0.0375,-0.3488,0.03>,<0,0,1>
actl/<0.0375,-0.3489,0.0247>,<0,0,1>
targ/<0.0375,-0.3488,0.03>,<0,0,1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point4 =feat/contact/vector point/default,cartesian
theo/<-0.1964,0.34,0.03>,<0,0,1>
actl/<-0.1964,0.34,0.0252>,<0,0,1>
targ/<-0.1964,0.34,0.03>,<0,0,1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point5 =feat/contact/vector point/default,cartesian
theo/<0.0263,0.4712,0.03>,<0,0,1>
actl/<0.0263,0.4711,0.025>,<0,0,1>
targ/<0.0263,0.4712,0.03>,<0,0,1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
plane1 =feat/plane,cartesian,triangle,no,least_sqr
theo/<-0.0813,-0.0065,0.03>,<0,0,1>
actl/<-0.0813,-0.0065,0.025>,<0.0013343,-0.0002879,0.9999991>
constr/plane,bf,point2,point5,point4,point3,,
outlier_removal/off,3
filter/off,wavelength=0
align2 =alignment/start,recall:a1,list=yes
alignment/level,zplus,plane1
alignment/trans,zaxis,plane1
alignment/end
prehit/0.045
retract/0.045
cylinder1 =feat/contact/cylinder/default,cartesian,in,least_sqr
theo/<0,0,-0.03>,<0,0,1>,0.194,0.06
actl/<0.0012,0.0174,-0.03>,<0.001373,0.001417,0.9999981>,0.1937,0.06
targ/<0,0,-0.03>,<0,0,1>
start ang=0,end ang=360
angle vec=<1,0,0>
direction=ccw
show feature parameters=no
show contact parameters=yes
numhits=6,numlevels=2,depth=0.03,end offset=0.01,pitch=0
sample method=sample_hits
sample hits=0,spacer=0
avoidance move=both,distance=0.15
find hole=disabled,onerror=no,read pos=no
show hits=no
align3 =alignment/start,recall:align2,list=yes
alignment/level,zplus,plane1
alignment/trans,zaxis,plane1
alignment/trans,xaxis,cylinder1
alignment/trans,yaxis,cylinder1
alignment/end
move/increment,<0,0,2>
move/increment,<2.35,0,0>
cylinder2 =feat/contact/cylinder/default,cartesian,in,least_sqr
theo/<2.25,0,0>,<0,0,1>,0.194,0.09
actl/<2.2495,-0.002,0>,<-0.0024484,-0.0005462,0.9999969>,0.1937,0.09
targ/<2.25,0,0>,<0,0,1>
start ang=0,end ang=360
angle vec=<1,0,0>
direction=ccw
show feature parameters=no
show contact parameters=yes
numhits=6,numlevels=2,depth=0.01,end offset=0.03,pitch=0
sample method=sample_hits
sample hits=0,spacer=0
avoidance move=both,distance=0.3
find hole=disabled,onerror=no,read pos=no
show hits=no
line1 =feat/line,cartesian,unbounded,no
theo/<2.25,0,-0.015>,<-1,0,0>
actl/<2.2495,-0.002,-0.015>,<-0.9999996,0.0008817,0>
constr/line,bf,2d,cylinder2,cylinder1,,
outlier_removal/off,3
filter/off,wavelength=0
align4 =alignment/start,recall:startup,list=yes
alignment/level,zplus,plane1
alignment/trans,zaxis,plane1
alignment/trans,xaxis,cylinder1
alignment/trans,yaxis,cylinder1
alignment/rotate,xminus,to,line1,about,zplus
alignment/end
move/increment,<0,0,2>
loadprobe/tool_15
tip/t1a0b0, shankijk=0, 0, 1, angle=0
move/increment,<0,-4,0>
move/increment,<1.3,0,0>
tip/t1a-35b-90, shankijk=-0.5736, 0, 0.8192, angle=-90
prehit/0.125
retract/0.125
point6 =feat/contact/vector point/default,cartesian
theo/<0.3883,0.5396,0.1367>,<-0.5735764,0,0.819152>
actl/<0.3905,0.5397,0.1336>,<-0.5735764,0,0.819152>
targ/<0.3883,0.5396,0.1367>,<-0.5735764,0,0.819152>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.5
show hits=no
point7 =feat/contact/vector point/default,cartesian
theo/<0.3168,0.473,0.0867>,<-0.5735764,0,0.819152>
actl/<0.3189,0.4728,0.0834>,<-0.5735764,0,0.819152>
targ/<0.3168,0.473,0.0867>,<-0.5735764,0,0.819152>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point8 =feat/contact/vector point/default,cartesian
theo/<0.3186,-0.4312,0.088>,<-0.5735764,0,0.819152>
actl/<0.321,-0.4315,0.0844>,<-0.5735764,0,0.819152>
targ/<0.3186,-0.4312,0.088>,<-0.5735764,0,0.819152>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point9 =feat/contact/vector point/default,cartesian
theo/<0.4365,-0.5322,0.1705>,<-0.5735764,0,0.819152>
actl/<0.4392,-0.5323,0.1673>,<-0.5735764,0,0.819152>
targ/<0.4365,-0.5322,0.1705>,<-0.5735764,0,0.819152>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.3
show hits=no
plane2 =feat/plane,cartesian,triangle,no,least_sqr
theo/<0.3651,0.0123,0.1205>,<-0.5735764,0,0.819152>
actl/<0.3674,0.0122,0.1172>,<-0.5743277,-0.0003714,0.8186254>
constr/plane,bf,point6,point9,point8,point7,,
outlier_removal/off,3
filter/off,wavelength=0
cylinder3 =feat/contact/cylinder/default,cartesian,in,least_sqr
theo/<0.7281,0,0.2805>,<-0.5735764,0,0.819152>,0.6287,0.7151
actl/<0.7335,-0.0094,0.2843>,<-0.574195,-0.0000904,0.8187185>,0.6293,0.7151
targ/<0.7281,0,0.2805>,<-0.5735764,0,0.819152>
start ang=0,end ang=360
angle vec=<0.819152,0,0.5735764>
direction=ccw
show feature parameters=no
show contact parameters=yes
numhits=8,numlevels=2,depth=0.1,end offset=0.515,pitch=0
sample method=sample_hits
sample hits=0,spacer=0
avoidance move=both,distance=0.5
find hole=disabled,onerror=no,read pos=no
show hits=no
move/increment,<0,0,4.5>
move/increment,<0,-2.5,0>
tip/t1a-95b0, shankijk=0, -0.9962, -0.0872, angle=0
move/increment,<0,-2.5,0>
move/increment,<0,-2,0>
move/increment,<0,0,-9.5>
point10 =feat/contact/vector point/default,cartesian
theo/<0.0212,-0.6137,-0.125>,<0,0,-1>
actl/<0.0212,-0.6136,-0.0961>,<0,0,-1>
targ/<0.0212,-0.6137,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.225
show hits=no
point11 =feat/contact/vector point/default,cartesian
theo/<0.3233,-0.2962,-0.125>,<0,0,-1>
actl/<0.3232,-0.2962,-0.0958>,<0,0,-1>
targ/<0.3233,-0.2962,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point12 =feat/contact/vector point/default,cartesian
theo/<0.6381,-0.5274,-0.125>,<0,0,-1>
actl/<0.638,-0.5274,-0.0956>,<0,0,-1>
targ/<0.6381,-0.5274,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point13 =feat/contact/vector point/default,cartesian
theo/<1.1921,-0.4793,-0.125>,<0,0,-1>
actl/<1.192,-0.4791,-0.0947>,<0,0,-1>
targ/<1.1921,-0.4793,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point14 =feat/contact/vector point/default,cartesian
theo/<1.7334,-0.3241,-0.125>,<0,0,-1>
actl/<1.7333,-0.3241,-0.0938>,<0,0,-1>
targ/<1.7334,-0.3241,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.15
show hits=no
point15 =feat/contact/vector point/default,cartesian
theo/<2.0356,-0.5301,-0.125>,<0,0,-1>
actl/<2.0355,-0.5301,-0.0932>,<0,0,-1>
targ/<2.0356,-0.5301,-0.125>,<0,0,-1>
snap=no
show feature parameters=no
show contact parameters=yes
avoidance move=both,distance=0.3
show hits=no
plane3 =feat/plane,cartesian,triangle,no,least_sqr
theo/<0.9906,-0.4618,-0.125>,<0,0,-1>
actl/<0.9905,-0.4617,-0.0949>,<0.0014699,-0.0002264,-0.9999989>
constr/plane,bf,point10,point15,point14,point13,point12,p oint11,,
outlier_removal/off,3
filter/off,wavelength=0
move/increment,<0,-2.85,0>
move/increment,<0,0,10>
align5 =alignment/start,recall:startup,list=yes
alignment/level,zminus,plane3
alignment/trans,zaxis,plane3
alignment/trans,xaxis,cylinder1
alignment/trans,yaxis,cylinder1
alignment/rotate,xminus,to,line1,about,zminus
alignment/end
dim loc1= location of cylinder cylinder3 units=in ,$
graph=off text=off mult=10.00 output=both half angle=no
ax nominal +tol -tol meas max min dev outtol
y 0.0000 0.0010 0.0010 -0.0095 0.3052 -0.3241 -0.0095 0.0085 <--------
end of dimension loc1
point1 =feat/point,cartesian,no
theo/<1.012,0,0>,<-0.5735764,0,0.819152>
actl/<0.9994,-0.0094,0>,<-0.572991,-0.0002757,0.8195616>
constr/point,pierce,cylinder3,plane3
point16 =feat/point,cartesian,no
theo/<0.6838,0,0.4687>,<-0.5735764,0,0.819152>
actl/<0.6919,-0.0095,0.4399>,<-0.572991,-0.0002757,0.8195616>
constr/point,pierce,cylinder3,plane2
dim dist1= 2d distance from point point16 to cylinder cylinder1 par to xaxis,no_radius units=in,$
graph=off text=off mult=10.00 output=both
ax nominal +tol -tol meas max min dev outtol
m 0.6830 0.0050 0.0050 0.6919 0.6919 0.6919 0.0089 0.0039 -------->
dim dist2= 2d distance from point point1 to cylinder cylinder1 par to xaxis,no_radius units=in,$
graph=off text=off mult=10.00 output=both
ax nominal +tol -tol meas max min dev outtol
m 1.0120 0.0050 0.0050 0.9994 0.9994 0.9994 -0.0126 0.0076 <--------
  • in reply to Mflores2324
    Good lord. Positional control and then everything things else is liner. So over dimensioned..... That doesn't fix your issue though... 1 thing that makes code so much easier to read. Re-name your features to the DATUMS on the print. Switch you program around. Yeah it will be longer..... Check A. Level and Set Z. Then check B and C. NEW alignment. Level to A, Rotate to B-C, Set Z on A, Set X and Y on B. Now check angled cylinder. Then create intersection from CYL to A. And use postion. Why are you suing distance and location anyways ?
  • Okay, so here's a few suggestions/ideas.

    1) Make sure probes are calibrated correctly in respect to each other. As someone said look up 'MASTER PROBE' and get your head round the concept then make sure you're stacking to it.

    2) Alignment should be Level > Rotate > Origin (in that order) but I don't think in your case it will matter (but as a test you can always dimension the datum features and check they measure zero in their respective axis)

    3) If you change your program to establish the alignment ABC first, you can then offset by 1.012 and then round by 35° so you're 'looking' straight down the cylinder. (XYZ will be 0,0,0 and vector will be 0,0,1) before measuring the angled cylinder.

    3) Make sure your constructed planes are don using best fit recomp (currently they're just best fit)

    4) Report the form of your features (datums and cylinder) to make sure you're not shanking out or have a bad hit somewhere in the datums skewing the results.

    5) Finally, you're saying the CMM results are wrong, but how are you verifying this or checking it otherwise? Are you sure the part isn't bad?

  • in reply to NinjaBadger
    Ok thank you, I will these suggestion out hopefully I get good results. And we checked the center of the holes with an Indicator and the Keyence/gage pins for the other dims
© 2024 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement