Datums on Angular Dimensions
Datums on Angular Dimensions
(OP)
Hi,
I'm currently working on a drawing for a part that requires two round studs to be centered on the part relative to the outside edges of the part. The two studs (Ø.063) are currently controlled using datums A and B, but I want to add a third datum C to control the last DOF. My initial thought was to add datum C to the 15.0° angular dimension, but SolidWorks indicates that "Only 1982 style datums can be placed on angular dimensions." What is a correct way to place a datum in the center of this part using the surfaces currently controlled by the 15.0° dimension?

I'm currently working on a drawing for a part that requires two round studs to be centered on the part relative to the outside edges of the part. The two studs (Ø.063) are currently controlled using datums A and B, but I want to add a third datum C to control the last DOF. My initial thought was to add datum C to the 15.0° angular dimension, but SolidWorks indicates that "Only 1982 style datums can be placed on angular dimensions." What is a correct way to place a datum in the center of this part using the surfaces currently controlled by the 15.0° dimension?






RE: Datums on Angular Dimensions
When I select a feature of size datum feature, I prefer something accurate. How are you doing to fixture to an inaccurate angle? I suggest using one of your studs as an FOS datum feature. Use a profile tolerance to control your outline.
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JHG
RE: Datums on Angular Dimensions
The question is why? Why the remaning degree of freedom should be arrested or stopped? What is the physical reality of this assembly?
Can the simultaneous requirement do the job ?
Profile all around for the outside feature (along with basic for radii and angles ex: .060, 35°, 615, 15°, 365, 190) and I think you are good to go.
RE: Datums on Angular Dimensions
RE: Datums on Angular Dimensions
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
RE: Datums on Angular Dimensions
Your datum A constrains 3 degrees of freedom
Your datum B constrains 2 degrees of freedom
To constrain 1 remaining DOF make dimension .365 datum C
Your part is now fully constrained
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Datums on Angular Dimensions
I'm not saying this is a good idea, but you didn't ask that.
pylfrm
RE: Datums on Angular Dimensions
Also, thank you CheckerHater and pylfrm for your responses. Thank you pylfrm for most directly answering my question. I will keep your suggested steps in mind for the future.
RE: Datums on Angular Dimensions
RE: Datums on Angular Dimensions