Cam Curve selection issues

[Sensiblenick]

Hi All..
First time posting here, and hopefully in the future I'll be able to offer help for others

I've just created a cam surface inside a ring (and another ontop of it) by using sketched graphs to drive dimensions on a variable section sweep. (similar to the method as described here

http://www.proengineertips.com/index.php?option=com_content&task=view&id=41&Itemid=72

)

Switching in to ProMechanism, I had expected to be able to select the resultant surfaces and use them as cam surfaces to set up a simple motion. However....

QUESTION:
It seems as though ProMechanism fails to recognise surfaces created by a variable section sweep as being usable as cam surfaces.

There are no sharp edges: Everything is tangential and smooth...
I have tried selecting edges and surfaces alike...
AutoSelect fails to pick up on the chain of surfaces...
Extruding the cam-profile will work for the internal cam curve... but not for the one on the top surface.

I'm at a bit of a loss.

Does anyone have a cunning tip or trick that will allow me to continue?

Many thanks..

Nick.
In "Sunny" Sweden. (mist and fog)

 

[JohnAndrews]

Nick,

I downloaded the cam from the tutorial which you linked to, and was able to define this as a cam with a suitable follower in mechanisms without any problem.
You sometimes find that the second cam (in my case the follower) asks for a front and back reference to help it understand the width of the cam, but apart from that works okay. Cams can only be planar 2D - do the joints which you have defined meet this requirement?

John

 

[Sensiblenick]

Hi again )

Thanks for taking the time to look over the problem: The cam from the tutorial is a shade simpler than the one I'm trying to use.

http://www.sharebigfile.com/file/27729/camsrus-01.zip.html

If you follow this link, pop in teh 3-digit code and wait a few seconds, You should be able to download the cam that I'm experiencing the troubles with.

I'm not sure how to describe the problem.. It simply won't allow me to select more than one surface. (Neither on the internal surface, nor the "top" cam.... Each cam curve is made from 18 surfaces.... but usually "autoselect" takes care of this. Today it seems things are different...

enjoy!! )

and thanks!!

 

[JohnAndrews]

Nick,

Thanks for sharing your data.
As I mentioned in my previous reply, Mechanism cams only work in 2D planar space, so your horizontal cam will be fine, but the vertical one is not possible using cams.
The best work around which I can suggest is to use a slot follower instead of a cam for the VERT_CAM surface.
This does not correctly mimic cam movement, but might be good enough to visually represent the movement required.

And put in an enhancement request for 3D cams!!!

Good luck
John