Modelling a barrel cam

[JHTH]

Something for the weekend...

I'm trying to accurately model a barrel cam, which is produced by running a milling cutter along a defined path around the surface of a cylinder but the result so far isn't quite right.

I've sketched the cam profile, applied a symmetric offset, Wrapped the curves around the cylinder and then done a Divide Face. I've then used the Synchronous Offset Region command to get the cam track, but this leaves material that would in reality be removed by the milling cutter (in the attached assembly, the cam follower should be horizontal but it's not).

I've tried simulating the cutter by extruding a circle, which is tangential to the surface of the cylinder, along the centreline of the cam profile, but it kicks me out with a 'self-intersection' error message. Can anyone suggest a better way to do it?

Thanks in advance,

Jon

JHTH
NX 7.5.5 + TC 8.3.2.2

 

[mmauldin]

In the attached model I created the groove the way I usually create features of this type. The result doesn't look much different that yours. I used a different approach to constraining the cam follower and it seems to follow the cam pretty well, although it is a bit jumpy as I drag it around the periphery.

 

[JHTH]

Thanks for the reply. On reflection I think I was making life difficult for myself just because of the way I was constraining the follower.

I've compared my original way to your way and I also swept a rectangle along the same path and cut that out of the solid. All 3 ways seem to give exactly the same geometry, give or take a fraction of a micron, so I'm happy enough that any of these will be fine.

Thanks again,

Jon

JHTH
NX 7.5.5 + TC 8.3.2.2