Aligning two axis
Aligning two axis
(OP)
I am trying to figure out what I have to use to make two cams, one on each end of a roller, to be aligned with one another. The cams have an alignment hole in the same spot. I'm confused with the datums and if I even need them.





RE: Aligning two axis
Fundamentally just showing to items aligned does not imply any relationship - you have to somehow tolerance this.
The best way to do this varies with situation.
For instance if the roller is long and the cam function related to its OD then it may make sense to make its OD the datum feature.
You could then relate both 'cams' to the roller OD.
Alternatively it may make sense to relate whatever mounts to the cam alignment holes.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Aligning two axis
If you want to design a shaft the cams will be attached to, look into ASME Y14.5-2009 Fig.4-40 and Fig. 4-41.
RE: Aligning two axis
But because you are talking about lobed cams, the best GD&T option is profile. This would control the shape, size, orientation, and location (axial only) of the two cams. Just as profile can be used to align two coplanar flat surfaces, I'm thinking that a similar scheme can be constructed here. Just do an all-around profile tolerance (no datum references) on the cams and be sure to say 2 places or something.
However, I'm interested in others' comments on my suggestion.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Aligning two axis
RE: Aligning two axis
RE: Aligning two axis
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com