I don't know what this true position on the hole is constraining. Bolt circle diameter or orientation of the hole maybe? Trying to determine if I need to measure the hole as a cylinder. Appreciate the help.
The only slight difference in interpretation to
NinjaBadger 's explanation comes from the fact that there is no Ø symbol preceding the positional tolerance - as was pointed out by
Matthew D. Hoedeman in comment 5.2. With no Ø symbol, the tolerance becomes a planar zone and, since only the 60° angular relationship between each hole is a boxed dimension (the BCD isn't), then you should set the zone orientation control in the Geometric Tolerance command to "right angle to radial" I've simulated this using the Hexagon training block and included a screenshot of the graphics window showing the tolerance zone's.
The Ø4 BCD is controlled separately and can be reported as a circle, constructed through the centroids of the 6 holes as
Jignesh was describing. You would just report it using a location dimension of the diameter to whatever the ± tolerances are (they're not shown on the original poster's screenshot).
However if it were me I'd seek clarification whether this is simply an omission/mistake on the part of the designer. I can't think of a functional reason why they'd want to control bolt hole position (with MMC) in an angular way but not radially.
However if it were me I'd seek clarification whether this is simply an omission/mistake on the part of the designer. I can't think of a functional reason why they'd want to control bolt hole position (with MMC) in an angular way but not radially.
