Setting up base alignment and measure true position

[[Ma...]]

Please, need some help on how to create a base alignment and measure true position for the following, 2x (H7) Datum B 4.000mm holes and (H7) Datum C 3.000mm hole. I’m not sure how you would create this in calypso!

[[Cl...]]

Measure two circles on each of the (top/bottom) 25.00mm diameters (-D-) and recall those feature points into a cylinder, or a 3d line. Use that for you Z spatial and XY origin. The top plane (Datum -A-) would be the Z origin. Then measure a cylinder in the 4.00MM (Datum -B-) hole and intersect it with the -A- plane. Use that for you planar rotation (Y+). This is for you BA only. For the T/P call out, measure the remaining datums and place them inside the position characteristic as called out on the print.

[[Me...]]

Can't read the entire FCF for -B-. What is after A as the Primary Datum?

[[Ma...]]

Thanks for the help Clarke Gilbert.

Robert Davis, thats one of the issues I have with this call out. Datum B is only re-called to A which is a Plane?

[[Me...]]

Create your Base Alignment as Clarke stated to get a stable starting point. Measure -A- as a plane. Measure the 2 holes that create -B- and create a Best Fit true position characteristic with -A- selected and with both translation and rotation allowed of the hole pattern. Measure -C- and create a true position characteristic and use the alignment that was created by the Best Fit of -B-. You have a problem with -D-. -A- and -B- already constrain all degrees of freedom so -C- does nothing. Use the same Best Fit pattern of -B- you used for -C- to report -D-.

[[Ma...]]

Thanks robert Davis. So, inside best fit you select features Datum A and also the two 2 holes?

[[Me...]]

No. Use a True Position characteristic. Inside of that select -A- as your Primary datum. Input your tolerance. Up above click on the Best Fit of Bore pattern icon. It's the one on the right of the 2. Open the Bore Pattern and select the 2 holes for B with Select Features. Below that leave the 2 boxes checked that say Rotation and Translation. Hit calculate now & ok. Make sure the Shape of Zone is the 2 axis you want to report. If you want, hit the graphic icon on top right to create a nice visual of what's going on to see the Best Fit offsets it used to fit the pattern.

[[Ma...]]

works great, thanks for all the help guys.