One of the things I think you are getting at is: Choose datum features for downstream assemblies from the set of datum features used for the upstream components (piece parts or sub assemblies).
Also love your hole and slot datum features. This strategy allows the hole to be sized MMC to the MMC of whatever goes through as can the width of the slot. The slot length can be minimized to the sum of the variation(s) in location of the slot relative to the hole and between the two whatevers that go through them. Very precise locating can be achieved. Much less "float" than if one restricted their manufacturing process to using only holes!
One of the things I think you are getting at is: Choose datum features for downstream assemblies from the set of datum features used for the upstream components (piece parts or sub assemblies).
Also love your hole and slot datum features. This strategy allows the hole to be sized MMC to the MMC of whatever goes through as can the width of the slot. The slot length can be minimized to the sum of the variation(s) in location of the slot relative to the hole and between the two whatevers that go through them. Very precise locating can be achieved. Much less "float" than if one restricted their manufacturing process to using only holes!
Lovely piece, Glen Turley
Nicely brings out the nuances between design specs and manufacturing fitment -and the unseen compromises many times required in an imperfect world.
Thank you for great article.