Datum & DOF
Datum & DOF
(OP)
Hi All,
I saw a drawing where primary datum and secondary datum constraining all the 6 DOF, but they have used 3rd datum also, I felt which is wrong. before I question the Engineer, I wanted to get it clarified with you that, by any change can we have 3rd datum, when we can constrain all DOF with the primary and secondary datums.?
I saw a drawing where primary datum and secondary datum constraining all the 6 DOF, but they have used 3rd datum also, I felt which is wrong. before I question the Engineer, I wanted to get it clarified with you that, by any change can we have 3rd datum, when we can constrain all DOF with the primary and secondary datums.?





RE: Datum & DOF
RE: Datum & DOF
RE: Datum & DOF
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
http://www.gdtseminars.com
RE: Datum & DOF
SesasonLee
RE: Datum & DOF
Hi Seasonlee, I dont have the sketch with me right now. :(
RE: Datum & DOF
If I have a concentric part, there is no need to control rotation about the main axis. 5 DsOF will constrain the part adequately. This is true up to the first non-concentric feature, such as a flat face or pitch circle.
When you add the second non-centric feature, you have to control clocking.
--
JHG