how to measure a slot hole

[szvincent010]

I have some experience with coding my CMM, but recently I have been asked to determine the true position of a slot hole. Partially the drawing is calling out the TP for the front half of the slot hole but not the entire slot hole. I am trying to constrain the entire slot hole based on true position of 0.5. Previously we just measured the entire slot hole and created a center point but it was not accurate and gave random data. Currently I am simply measuring the front of the circle but I would like to control the entire slot hole. Pictures for reference. If there is anyway to assist me, please help me.

[Roberto]

Create a "Generic circle" with the width and the mid point to report 0.5 TP at MMC.

[JEFMAN]

I would like to control the entire slot hole.

Do you have a scanning probe ?
I would try constructing the slot from the entire surface, then dimension the center.

[Matthew D. Hoedeman]

I don't think that callout is controlling one end of the slot, but the entire width of the slot. If you are using POSITION, you should be able to just use a single axis in the position dimension and all it will report is the deviation in that axis. DO NOT USE PERP TO C/L in the position dimension or it will use both directions.

[VinniUSMC]

If you use position of a slot with MMC, then the MMC will come from the axis that has the least tolerance, regardless of which axis you choose to report. Create generic circles on the XYZ of the slot, and use D for the width and L for the length.

[VinniUSMC]

I have some experience with coding my CMM, but recently I have been asked to determine the true position of a slot hole. Partially the drawing is calling out the TP for the front half of the slot hole but not the entire slot hole. I am trying to constrain the entire slot hole based on true position of 0.5. Previously we just measured the entire slot hole and created a center point but it was not accurate and gave random data. Currently I am simply measuring the front of the circle but I would like to control the entire slot hole. Pictures for reference. If there is anyway to assist me, please help me.

That TP is calling out the width of the slot. The two opposed flats of the slot. I prefer to select the feature with Auto Round Slot, and then change it to Auto Square Slot and "Measure Width" set to YES (adjust the radius as necessary to get the width hits on the flats.) Then, create 2 generic circles.

SLT_W      =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,OUT,$
            NOM/XYZ,<SLT_2.TX,SLT_2.TY,SLT_2.TZ>,$
            MEAS/XYZ,<SLT_2.X,SLT_2.Y,SLT_2.Z>,$
            NOM/IJK,<SLT_2.TI,SLT_2.TJ,SLT_2.TK>,$
            MEAS/IJK,<SLT_2.I,SLT_2.J,SLT_2.K>,$
            DIAMETER/SLT_2.TD,SLT_2.D
SLT_L      =GENERIC/CIRCLE,DEPENDENT,CARTESIAN,OUT,$
            NOM/XYZ,<SLT_2.TX,SLT_2.TY,SLT_2.TZ>,$
            MEAS/XYZ,<SLT_2.X,SLT_2.Y,SLT_2.Z>,$
            NOM/IJK,<SLT_2.TI,SLT_2.TJ,SLT_2.TK>,$
            MEAS/IJK,<SLT_2.I,SLT_2.J,SLT_2.K>,$
            DIAMETER/SLT_2.TL,SLT_2.L

[JEFMAN]

I agree with Matthew D. Hoedeman and VinniUSMC about the width, but in this case, I don't understand why there's a "Ø" in the tolerance value...

[VinniUSMC]

Yeah, that shouldn't be there.

[szvincent010]

trust me, I do not know either.. this is just what I am given to work with

[Matthew D. Hoedeman]

I agree with Matthew D. Hoedeman and VinniUSMC about the width, but in this case, I don't understand why there's a "Ø" in the tolerance value...

CUT & PASTE and fill in the blanks method of making a print. The FCF is a 'thing', for position, paste it in, fill in the blanks. Like bolts & nuts are in a cad package for designing tooling. They don't make a bolt model for every individual bolt, it is a 'menu item', paste it in location.

[JEFMAN]

CUT & PASTE and fill in the blanks method of making a print. The FCF is a 'thing', for position, paste it in, fill in the blanks. Like bolts & nuts are in a cad package for designing tooling. They don't make a bolt model for every individual bolt, it is a 'menu item', paste it in location.

A tool box shouldn't prevent the reflection ! Even if it's a nice tool box !

Hey, all, it's friday !
Have a nice week-end !