Datums in Drafter

At this step you’ll see Drafter’s “Detected Features” along with a prompt to select on your uploaded part. Some of these features may be auto-grouped.

<aside>
- How can I group and ungroup detected features in Drafter? </aside>
Next select your datums. Datums are the axis, surface, point, or plane that act as fixed points of reference and measurement when manufacturing or inspecting a part. Effective datums constrain 6 degrees of freedom. These are chosen based on features most critical to the part’s function (often mating surfaces.)

You can not select datums that do not constrain additional degrees of freedom
You may select groups of features, individual features, or surfaces
You must select datums that constrain your part to a minimum 5 degrees of freedom, but we encourage you to aim to constrain 6 degrees of freedom
You are required to select a minimum of 2 datums, but we encourage you to select 3 in order to fully constrain your part in space
Each datum selection will prompt a notification indicating your current degrees of freedom constrained
Currently, selecting beyond 3 datums is not supported by Drafter
After a datum is selected you’ll see it move from under “Detected Features” to “Critical Features” along with a datum symbol.

<aside>
- How should I pick my datums? </aside>
<aside>
- What are degrees of freedom? </aside>
To remove a datums, simply hover over the element in the “Critical Features” and select X. Removing a selected datums will wipe any following selected datums