I have this rod that has a datum A cylinder and datum B is center drill. I can create the common datum for a runout tolerance but when I create the runout feature it won't let me because they're 2 different feature types. So I created a generic cylinder out of the cone then PC DMIS didn't like that one feature had surface data and the other one didn't. I then created a generic cylinder out of the measured cylinder and then it would let me make my runout FCF feature. Why can't I make the common datum out of 2 different features?
1) Measure CYL_A 2) Measure CON_B 3) create generic points at.. -start of CYL_A -end of CYL_A -start of CON_B -end of CON_B 4) Construct a 3d line (LIN_AB) through the 4 points 5) Create a new alignment (ALI_AB).. -level through LIN_AB -make LIN_AB origin 6) While recalling ALI_AB, report the runout of the feature you want evaluated against your current alignment
Be careful with end point of a cone, I would check if it's the vertex or not... If so, the line wouldn't represent the right axis, because of the total length of the cone in front of the measured length...
Maybe constructing pierce points between axes and generic planes would give right results ?
In addition, a datum on a cone should be a cone tangent on athe free side of material... And I believe PC-DMIS (nor any other soft ?) is unable to do it...
neil.challinor ?
JEFMAN , when using the geometric tolerance command with the math type set to default, we recalculate using constrained L2 (ASME) or constrained min/max (ISO). This applies to all features that have surface data, including cones, is that what you mean? We do deviate slightly from the standards in that we only allow a cone to constrain 4 degrees of freedom whereas the standards say that they should constrain 5. The fifth degree of freedom is supposed to be translation along the axis of the cone but the standards are not very clear on how this is supposed to be determined.
JEFMAN , when using the geometric tolerance command with the math type set to default, we recalculate using constrained L2 (ASME) or constrained min/max (ISO). This applies to all features that have surface data, including cones, is that what you mean? We do deviate slightly from the standards in that we only allow a cone to constrain 4 degrees of freedom whereas the standards say that they should constrain 5. The fifth degree of freedom is supposed to be translation along the axis of the cone but the standards are not very clear on how this is supposed to be determined.
