GD&T Position with Datum Feature and Best Bore Pattern

[[To...]]

I used a Best Fit Bore Pattern Position of the 2 holes to A and B, allowing rotation, but how do you build a position of the center hole to Datum C and the Best Fit Bore Pattern?

[[Ma...]]

I would try this:

• make theoretical point at nominal origin ( as X=0 Y=0 )
• set feature alignment of the point as BF pattern
• make same way 3d line ( will be used only secondary )
• make new alignment
• put plane C as primary
• put previously created 3d line as secondary
• put previously created point as X,Y
• put plane C as Z

Now use that alignment

[[Ch...]]

I do similar when needed to reference a best fit pattern as a datum feature.

If it is for a rotation for example, I make a theoretical 3d Line and link it's alignment to the Best Fit.

[[Ky...]]

Hey Chris,

 

It might be worth trying to use the "parallel cylinder" option under features. I haven't used it a hole lot, but I think this is the intended use case.

 

 

Alternatively, you can try the new GD&T engine if you are using 2023 or newer and set these as a common datum. If the callout was like A|B|D, I would say just use the alignment from the bore pattern true position, but since it's a completely different alignment, these would probably be best.