Mates for Axial Cam 1

[DanStro]

Hello everyone,

I was hoping someone could help me get a model of an axial cam to work in SW.

The idea is that I want an inner cell to move along the axis of an outer cell that has a cut-out (not necessarily helical) around its OD. There is a pin attached to the inner cell perpendicular to the axis passing thru (no interference) the cut-out of the middle and into third larger cylinder with a slot cut straight along its axis, this last cylinder will be fixed while the middle (with the non-straight cut out) will be allowed to rotate. That way, when the middle cylinder is rotated the inner cell moves along the axis at a rate determined by the cut in the middle, but staying concentric with the axes of all three and not rotating.

My problem is the mate between the inner and middle cells. I have tried wrapping a curve onto the middle cylinders OD and extruding it and creating a helical curve and sweeping a sketch. Those will get me the cuts but when I try to mate the parts (inner and middle cells) I can't get the pin sticking out of the inner cell (perpendicular to its axis) tangent to the cut AND concentric to the other cells. I have also attempted a cam mate but that goes nowehere.

Right now the actual diameters and travels required are not important, its just getting to the point that I can model the movement.

I hope this is clear.

Any help is appreciated.
Dan Stroschine

 

[Theophilus]

If you go back to your curve idea, you should be able to make the part follow your track. (Picture would help for further help.)

Meanwhile, check out the movement along curves found at Mike Wilson's site:

http://www.mikejwilson.com/solidworks/solidworks_files.htm

Good luck.


Jeff Mowry

http://www.industrialdesignhaus.com

Reality is no respecter of good intentions.

 

[DanStro]

Theophilus,

I originally thought the wrapping a curve idea would be best too but I can't can't get the inner cells to stay concentric with the middle one. I can create a parallel mate between the axes but not a concentric mate.

I've downloaded a couple from the site you recommended but those looked like animations (really quick look). I want to be able see what would 'really' happen if the parts are they the way they are modelled.

Dan

 

[Theophilus]

Can you use a coincident plane mate instead of a concentric mate? That should allow you linear movement.

Check out the files and others from Wilson's site--there might be a way to do what you need. By the way, you might not get some of the parts to move by moving only one of the parts--they may tend to "bind"--so you may need to create an animation of some sort to get what you need. (Sometimes moving a part won't necessarily force the other parts to move, even if mated that way.)


Jeff Mowry

http://www.industrialdesignhaus.com

Reality is no respecter of good intentions.

 

[DanStro]

The problem with a plane mate is that now the inner cell movement is being controlled by that and not by the cut in the outer cells. The cut in the middle cell (not the straight cut) controls the speed that the inner cell moves along the axis.

I have gotten it to work using physical dynamics but that runs really slow.

I'll keep going thru that site though.

But I guess beggars can't be choosers.

Thanks again,
Dan