cam mate

I can't get to your jpg, but as a thought, can you set an axis of the pin to a distance mate from either end of the slot? Maybe have to add planes, etc, but possibility?

WT

Wayne,

Nice thought considering you can't see the picture. But the slot is not a simple straight slot. Imagine a straight slot along the axis direction, with a 90=B0 turn at each end to "lock" the inside cylinder from moving along the axis, on both ends.

One of the tricky things is that one of the ends that has the 90=B0 turn is "open" on the far side. It's kinda hard to explain. That's why I posted the picture. But, I thought I would compensate for this problem by adding a closed surface body to complete the slot loop. But that didn't work either.

By the way, why couldn't you see the picture? Bad link? Firewall? Etc.? I am asking to see if I posted the link correctly. If I did it wrong, then nobody would be able to see it. That wouldn't be very worthwhile... I would need to repost the picture link somehow.

Seth

Seth,

I was able to see it when I clicked on the link. My computer opened it in IE. Sorry, but I don't have time to mess with it right now. Work has me covered up, but that's a good thing.

Reaper.

I love stumping the noncertifiedsolidworksguru.

I think your troubles might be because you do not have a closed loop for your cam (unless I am missing something). From the SW help file: "You can make the profile of the cam from lines, arcs, and splines, as long as they are tangent and form a closed loop.". I ran into this a few weeks ago, and it's a PITA. BTW, I am using SW2007.

Debbie

I've done this type of mate before. Cam Mate can't do it because it requires the cam faces to be straight in one direction, as if they were extruded.

You're on the right track with an offset surface but it gets complicated fast. The basic problem is that you can't mate coincident to to more than one face. So, what you need to do is approximate the cam path with a single fitted spline. Since that only works in a 2D sketch, you then need to use a wrap or a sheet metal bend on a temporary body to create a surface from the fitted spline. This surface should have only one face. Then you can mate the point from the pin hole to this new surface.

Sometimes, the surface gets wavy, or gets broken into multiple faces. Try fiddling with the fit tolerance on the spline.

Even with this working, dragging the outer tube may be flaky. Sometimes moving the part with a Spaceball works better than dragging with the mouse, sometimes not. Some days it work as smoothly as you would hope. You also get a built in limit mate, since the fitted-spline surface is a procedural surface: the mated point won't go past the end of the surface.

You mention mating to the curve, which I've never tried. That should work, but you may get overdefined mate problems with the concentricity of the cylinders. I seem to remember reading somewhere thet curves can only be selected from the FMT. I don'tknow why they won't let you select them in the graphics area. Maybe this information is out of date. I just tried a couple curve entities in 07 SP5.0, and I was able to select them. I should try the curve method someday.

I hope that at least gets you to a viable idea.

Debbie,

I knew that was a cam mate rule. So, I tried creating a surface body that "closed" the end that is open, and use this surface body to mate to. Couldn't get that one to work either.

Seth

How about a surface on the centerline of the slot (or the closed up slot on the end) to an axis on the pin? If it works I'll take a beer in SD.

Jerry Steiger

This sounds like there may be a solution buried in there somewhere ;-)... Thanks. I'll play with these ideas.

As for selecting a curve, I could ONLY select the curve graphics area. And only then, could only select part of the curve (which I didn't even think was possible)....

Seth

I think I have something I could send as an example, if you need it.

Yes please! This is just about to drive me crazy.... I'm about ready to cave and send it to my VAR.... The only reason I haven't so far is, I want to finish this today, not a week from now....

Please send to snipped-for-privacy@NOSPAMhaywardnet.com get rid of the NOSPAM of course.

Thanks, Seth

Tried that. I have not been able to get that to work either... But I guess I could buy you a beer for the attempt anyway.... ;-)

Seth

I hope SW07 files are OK. On their way...

Just for a try, convert the faces of the slot to one single surface. Then sketch a point on the surface of the dowel and give a coincident mate to the surface and point.

Deepak

I tried that early on. The problem there is that you can convert the slot faces to one surface body as you mention, but it will still contain multiple faces. You can only mate a point coincident with one face.

I did end up doing something very similar as well.... I found a way to get the mate to "track" correctly. I simply extruded a fitspline surface (one face) along the centerline of the slot, created a sketch point on the dowel axis in a position that it contacts the surface in the slot.

It moves really well. The only problem now it that it doesn't "stop" at the ends of the slot. I tried using an angle limit mate to confine the rotation to stop at a desired angle. But as you might expect, every variation that I tried either over-defined it, or caused it to "jump" past where it should for some reason....

I think I will give up now.... :-)

"I did end up doing something very similar as well.... I found a way to get the mate to "track" correctly. I simply extruded a fitspline surface (one face) along the centerline of the slot, created a sketch point on the dowel axis in a position that it contacts the surface in the slot.

"It moves really well. The only problem now it that it doesn't "stop" at the ends of the slot."

This seems strange. Since the path is a spline, how does it extend it? Somehow it "knows" that the ends are really straight lines? Try putting a fairly sharp kink at the ends of your spline. That might stop SW from extending the spline. If it doesn't, at least you get a signal that you've reached the end of the "real" slot.

Jerry Steiger

I did not have time to post last night to show something but you concluded the same... here are my layout files for all...