Assembly cut parent/child relationships

[Tesla77]

I am trying to design a generic assembly that when a single component is deleted or suppresed that anything to do with that component is gone with it all at oce no reference errors.


Example: A block is the base component and I assemble a shoulder bolt to the block using the assembly datum planes for location offsetsand mate the thread end shoulder bolt surface to the block surface. I now create an assembly cut using the hole tool to create the thread in the block using the shoulder bolt axis and block surface. I now can delete or suppress the shoulder bolt and have the thread hole follow it. It is all tied together for when I no longer want the shoulder bolt and anything to do with it gone from my block.





Is the a proper procedure or are you supposed to activate the block, create the thread hole and assemble the shoulder bolt using the thread hole and block surface? I know if I go this route when i delete the shoulder bolt the hole stays or if I delete the hole the shoulder bolt stays. Than when upon regenerating the gray box pops up with references missing. I just want to know if the Examplpe above is a right way of designing in Pro-E.

 

[dr_gallup]

I would prefer to use groups. I try to avoid unnecessary external references like the plague. It makes model reuse so much easier.

 

[Tesla77]

If I activate the block and create the thread hole I can't group that to the shoulder bolt. And if I go the route where I am assembling the shoulder bolt to the thread hole it keeps them seperate when suppressing or deleting one of them. Example: If I delete the thread hole the shoulder bolt will stay until I regenerate, than the gray box will pop up with reference errors. If I suppress or delete the shoulder bolt the thread hole will stay in the block. I want them to be tied together so if I suppress or delete the shoulder bolt the thread hole goes with it. I want the shoulder bolt to be the master of all features to do with it so I can suppress or delete them all at once no strings attached.
Edited by: Tesla77

 

[dgs]

Think about what you are telling Pro|E in your method. You are saying that the position of the hole is dependent on the assembly and the position of the bolt. In other words, you can't make this hole until the part is assembled and the bolt is in place. Is that what you want? I think what you really want is that if the hole goes away, the bold goes away not the other way around.

I like to think about how it's going together in real life as I'm building. Of course, there are some part to part associativity possibilities in Pro|E that you can't do in the real world, but I like to start with the real world in mind. IN this case, you can't have the bolt without the hole, but it is possible that the hole with no bolt in it or a different bolt in it.

That said, I'd make my hole in the block first, and then assemble the bolt to the hole by aligning axes or inserting the cylinders and mating the underside for the head to the block surface.

This gives you a block that can be built with no knowledge of the assembly or the hardware being attached to it, just as you would want in the real world. You also get the associativity of Pro|E in the assy where the bolt relies on the hole position and moves with it. If the hole goes away, the bolt does to (or at least it fails). I can also take the bolt away and leave the hole, or change the shoulder bolt for a cap screw without effecting the hole.

The next step from there, if you wantmore associativity, would be to create an assy skeleton (requires teh AAX module) and define your hole position there. Then you'd pass that geometry down to the parts that need it (the block and whatever it's being bolted to) and build the holes on that geomerty. I'd still assemble the bolt to the hole in the block, however, because you don't want hardware to have any external references since thay are used over and over again in all kinds of assemblies.

 

[bwilson]

We have been setting up assemblies in the manner you are talking about. The order we have been using is:


1. Assemble the item (bolt in this case).


2. Put in the threaded hole in the assembly, but using the intersect option and setting it to the part level, so the hole shows up in the part.


3. As was mentioned in another post, then grouping all of this together in the assembly. This allows the bolt to be removed (or suppressed) and the threaded hole to be removed (supressed).

 

[Tesla77]

Is this a wrong way of designing with ProE? If it is done the way bwilson is agreeing with the grey message box never pops up or does any missing error boxes.


Is it wrong to assemble a component first in ProE? And than make features in assembly that tie to it?

 

[kdem]

If you create the hole at the assembly level and group the bolt with it it doesn't matter which comes first in the group because you suppress them at the same time when you suppress the group. Although what your doing works I would create the hole first, assemble the bolt, group them and then suppress the group.

 

[dgs]

Just be cause you can do it and it seems easier doesn't mean it's good practice. Is it the wrong way? Not sure I'd say that, but you are creating dependencies that you may not want.

The location of the hole is dependent on the bolt and the assy. You cannot do this in real life, is this what you want? What if you need to change the bolt from a SHCS to a pan head machine screw? Now the hole fails. Sure, you can fix it, but then you drawings will be messed upt too.

What if you decide that you only need 4 of the 6 bolts, but you want to leave the 2 extra holes incase a bolt is broken? Again, you can fix it, but why?

The parent child relationships in Pro|E are powerful, but I'm careful about what I make the parent and what I make the child. On the shop floor, when they are assembling thesse parts, the hole is the parent of the bolt. The hole decides where the bolt should go, I wouldn't flip that in Pro|E. I don't think you gain anything accept a little speed in the intial layout. I bet that whatever you gain there is lost and then some the first time you need to make a change like swapping fasteners.