Concentric mates- my little rant

Because a cocnentric mate can be either aligned or anti-aligned. Of course.

That has nothing to do with alignment per se.

A single concentric mate, when changed from aligned to anti-aligned, will flip the part along the 'axis' used to create the concetric mate. It is just as necessary to be able to change the alignment of a concentric mate as it is any other alignable mate.

If you create the mate to locate the part axially first and choose the proper alignment for that first mate, using 'closest' for the concentric mate will always work. Defer mate is invaluable in this type of scenario, because otherwise, invariably, the part wanders off into space or inside a body.

That having been said, it would be nice if SW offered some sort of visual feedback for which directions correspond to 'aligned' and 'anti-aligned' for the features that have been selected for the concentric mate. I, for one, can't always recall in which direction a feature was extruded/cut/etc.

Jim S.

Try mating your cylinders using smart mates. Select your cylindrical surface and drag it to another cylindrical surface if it is facing the wrong way hit tab and it flips. Another option is instead of selecting the face select the edge of the axial surface and the cylindric surface and drag it to the one you want to mate to, this creates both the axial and cylindrical mates.

Corey

I suppose, I never gave much thought to it before, I can put a nut on a bolt either way, unless I'm using a buttress thread, just seems to be an extra step to me.

I have to change 2 mates to flip the nut, when in my dense little mind I shouldn't have to change the alignment of the concentric one. :o/

I little arrow showing which way is UP would be nice, but so would a lot of things.

I *did* say it was a little rant :o)

Thanks for the reply, Whit

Thanks for the swift kick Corey :o) I'd played with smartmates before and found either they or I was too dumb. I just tried again and they're beginning to make some sense, fewer clicks I hope.

Whit

Corey Scheich wrote:

Tip for concentric mates. I apologise if this is obvious, but sometimes the obvious is not obvious. I have got into the habit of inserting an axis thro any major round feature of parts that I create. The reason for doing this, when you start to put an assembly together you can pick the axis of the parts/sub-assembly parts straight off the feature tree. No flying around the screen, hiding objects ect to locate your mating features.

Cheers

Brian

If You're in SW2004 try to pick a face and then hold down alt key while dragging .. like smart mates when You find the other face

whit skrev i diskussionsgruppsmeddelandet: snipped-for-privacy@mywayREMOVE.com...

Why put a new, specific axis in when, in most cases, there is already a temporary axis there? They are very much usable for mates, etc.

WT

the specific axis is more useful because you can select it directly from the feature tree....

particularly when you've got a whole bunch of revolved parts, it can become difficult to make sure you've got the correct temporary axis...

Also if you have an assembly with alot of temporary axii you can suffer quite a bit of lag if they are visible.

Corey

I submitted an ER at one time to be able to select a temp axis using the RMB popup menu of any axisymmetric surface. Thus, eliminating the need to "Show Temporary Axes." All you would do, is right click on the cylinder's surface, select 'Select Temporary Axis' from the popup menu, and be done.

Let's get some more of us to submit this ER and move it higher on SWX's priority list.

I'm with Whit on this one.

Direction on concentric mates is redundant. Usually the direction is driven by some other constraint, like the head of a bolt against a mounting surface.

I can't think of any instances where having direction on a concentric mate was of any real advantage. I would be interested to hear of a real-world example to the contrary.

How about a pneumatic cylinder. You want the rod to float. I guess in 2004 you would add a limit mate though. I have used it. It would be nice if it were optional or just a one time thing instead of a constraint. then if you flip a bolt to the other end of a bolt hole it would just flip when you mated to the new surface instead of causing the design tree to light up until you flip the concentric alignment.

That is a good idea as sometimes turning on the temps takes a few minutes.

WT

Dear Mr/Mz/Mrs/Miss The Tick

It's only redundant* if you've created the other mate first.

However, in this case, when it comes time to add the concentric mate, all you need to do is ask for 'closest' when you are asked to specify the mate direction.

If you want to create the concentric mate first, it seems to me you are asking the software to arbitrarily choose a mate direction on your behalf, and it would stand a 50% chance of getting it wrong. It has to choose a direction because it has to solve the mate.

Or are you thinking of a new type of directionally ambiguous mate which allows its direction to be flipped by subsequent mates?

If this is what you are wishing for, I for one hope it doesn't get granted, I can see a bunch of complications, and fairly narrow benefits in comparison with the present "closest" functionality.

The advantage of not having to flip the concentric mate when you later change the direction of a component would seem to me to be outweighed by the need to keep track of the specialised and untypical behaviour of that particular mate in that particular situation., and it would leave certain situations unable to be mated at all, like this:

• others have already instanced cases where it is not redundant at all, like an axially sliding (underconstrained) pin-in-hole situation.