Assembly constraints

[dross]

Why does a mate always default to 'Normal'?
Doesn't make any sense, didn't do it prior to Creo2.
Irritating as hell changing it all the time from normal to coincident. Default should be coincident, not normal, not distance.

Another related item: Insert is now coincident, makes it harder to pick the correct constraint to change when a flat surface to a flat surface is treated the same a a cylindrical to cylindrical... change insert back to insert!!

 

[silverado8405]

Why does a mate always default to 'Normal'?
Doesn't make any sense, didn't do it prior to Creo2.
Irritating as hell changing it all the time from normal to coincident. Default should be coincident, not normal, not distance.

Another related item: Insert is now coincident, makes it harder to pick the correct constraint to change when a flat surface to a flat surface is treated the same a a cylindrical to cylindrical... change insert back to insert!!

Glad to know I'm not the only one with this exact same complaint!

 

[neomechanikos]

Yes, it is frustrating. It can be adjusted/disabled though. The default behavior is that it makes assumptions based on the orientation of the components when the assembly constraint is initially created. Reorient the component to change the assumptions that Creo makes. That being said, you can customize how it behaves by changing a few options:

auto_const_always_use_offset
Yes - auto constraint always creates offsets.
No - Auto constraint snaps align or mate if surfaces are within tolerance. (Default behavior)
Never - Auto constraint never creates offsets.

If you choose to use the default behavior of working within a tolerance (epsilon) you can specify the epsilon to give you more or less room to make it behave according to your preferences.

comp_normal_offset_eps
comp_angle_offset_eps
auto_constr_offset_tolerance

The idea being similar to sketcher where Creo makes assumptions based on how you initially position and orient entities. So if you want it to make an offset, just re-position the component further than epsilon before you make the constraint....within epsilon and it makes it coincident. It may take some adjusting until you find something that works for you. Hope that helps.

 

[dross]

I don't position a component prior to creating constraints. I just start creating constraints. To position it ahead of time is an extra step or two that should not have to be utilized.
I have the auto_const_always_use_offset set to no, yet it always uses offsets...if it does not default to "normal", which it usually does.

 

[neomechanikos]

Sounds like you need to set auto_const_always_use_offset to "never".

As for the normal constraint I set the following and it basically disabled the "Normal" and "Angle" constraints:

comp_angle_offset_eps 91
comp_normal_offset_eps -1

I suppose you could specify greater/lesser values if you want.....359 and -359 so as to almost never have them come up again.

 

[design-engine]

I could make a whole slew of issues with Creo 2 assemblies. Maybe some issues I have could be eliminated with a configuration change I don't know.

For one when I make a constraint it defaults to a distance. I want the default to be coincident.

 

[neomechanikos]

Sounds like you need to set auto_const_always_use_offset to "never".

As for the normal constraint I set the following and it basically disabled the "Normal" and "Angle" constraints:

comp_angle_offset_eps 91
comp_normal_offset_eps -1

I suppose you could specify greater/lesser values if you want.....359 and -359 so as to almost never have them come up again.

Did you try the above config changes? They worked for me.

 

[Volunteer]

Thanks for the settings neomechanikos, they worked great.

 

[dross]

Yes, I made the changes, it still does the same thing.

 

[neomechanikos]

Dross, go to configuration editor, under "Show" select Current Session. And verify that your current session has loaded the following settings:

auto_const_always_use_offset NEVER
comp_angle_offset_eps 91
comp_normal_offset_eps -1

I tried the settings on another computer and it worked as well. If something is overriding your settings (config.sup,etc.) then you should see what is really happening the current session config.

 

[dross]

After I set the epsilons, it acts as you describe.
Thanks!

 

[zpaolo]

Good to know the "normal" annoyance can be resolved, but I still hate the fact that "inserts" are treated as "coincident": When placing multiple instances of the same part I sometimes use the "repeat" feature, which is lovely, except now it's a hell of a lot more difficult to tell if that "coincident" constraint is a planar coincident or an insert :/

 

[dross]

Sucks, doesn't it?

but I still hate the fact that "inserts" are treated as "coincident": When placing multiple instances of the same part I sometimes use the "repeat" feature, which is lovely, except now it's a hell of a lot more difficult to tell if that "coincident" constraint is a planar coincident or an insert :/