Constructed Cylinder puzzle

[derrickcoyne]

This one has me stumped! I have a part with 2 bores, datums F and G, about 75 mm apart. They are coaxial, the only difference is diameter. I need to construct a cylinder that runs the length of both bores, but is the same diameter of the smaller (F). Trying to construct a cylinder directly from the cylinders gives me the illegal number of inputs, or math fails. Constructing a cylinder using the paramaters of G but the diameter of F also fails in the same way. Constructing a generic cylinder with the paramters of G and diameter of F, and then constructing the cylinder from the generic and F, the resulting cylinder is not not coaxial with the parent cylinders. Is there a way to do this? I have the datum set right now as a line, but i would really prefer a 3d feature controlling this datum structure. Thanks!

derrick

[gibsonridge]

have you tried measuring 4 circles in each bore to create a cyl. for each then construct line thru 8 circles

[JEFMAN]

I would try constructing a max inscribed cylinder from hits of both cylinders. It could work only if the number of levels of F is 3 or more.
Another way is constructing circles on F and G, create a line from centers and then using this line in a generic cylinder, and F as diameter.

It's friday, happy week-end, all !

[Matthew D. Hoedeman]

a line CAN BE a 3D feature, it is a toggle option 2D or 3D.

As for making a cylinder, if you go to INSERT~FEATURE~CONSTRUCTED and select cylinder, THEN hit F1, it will tell you what the acceptable inputs are. Depending on your version you may have more or less than someone else.

[neil.challinor]

have the datum set right now as a line, but i would really prefer a 3d feature controlling this datum structure. Thanks!

If you already have the 3D line and just want to turn it into a cylinder that is the same diameter as your datum F, just use a generic feature as has already been suggested by other people on this post. Example code would be....

STARTUP    =ALIGNMENT/START,RECALL:USE_PART_SETUP,LIST=YES
            ALIGNMENT/END
            MODE/MANUAL
            PREHIT/0.5
            RETRACT/0.5
            MOVESPEED/ 500
            TOUCHSPEED/ 4
            FLY/ON
            FORMAT/TEXT,OPTIONS, ,HEADINGS,SYMBOLS, ;NOM,TOL,MEAS,DEV,OUTTOL, ,
            LOADPROBE/HP_TMB_SF_2X20
            TIP/T1A0B0, SHANKIJK=0, 0, 1, ANGLE=90
DATUM_F    =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<0,0,0>,<1,0,0>,30,10
            ACTL/<0,0,0>,<1,0,0>,30,10
            TARG/<0,0,0>,<1,0,0>
            START ANG=0,END ANG=0
            ANGLE VEC=<0,0,-1>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
DATUM_G    =FEAT/CONTACT/CYLINDER/DEFAULT,CARTESIAN,IN,LEAST_SQR
            THEO/<75,0,0>,<1,0,0>,60,10
            ACTL/<75,0,0>,<1,0,0>,60,10
            TARG/<75,0,0>,<1,0,0>
            START ANG=0,END ANG=0
            ANGLE VEC=<0,0,-1>
            DIRECTION=CCW
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
LIN1       =FEAT/LINE,CARTESIAN,BOUNDED,NO
            THEO/<0,0,0>,<75,0,0>,75
            ACTL/<0,0,0>,<75,0,0>,75
            CONSTR/LINE,BF,3D,DATUM_F,DATUM_G,,
            OUTLIER_REMOVAL/OFF,3
            FILTER/OFF,WAVELENGTH=0
            ASSIGN/V1=LIN1.ALL
F1         =GENERIC/CYLINDER,DEPENDENT,CARTESIAN,IN,$
            NOM/XYZ,<V1.TX,V1.TY,V1.TZ>,$
            MEAS/XYZ,<V1.X,V1.Y,V1.Z>,$
            NOM/IJK,<V1.TI,V1.TJ,V1.TK>,$
            MEAS/IJK,<V1.I,V1.J,V1.K>,$
            DIAMETER/DATUM_F.TD,DATUM_F.D,$
            DISTANCE/V1.TL,V1.L