How to make an assembled parts position permanent out of assembly file

[Drkwing]

I'm sorry if the title doesn't make any sense. The explanation is as follows:

- Suppose we have a bunch of parts to be assembled.
- We add the parts to an assembly file and assemble them using mating relations (3d constraints)
- By using mates we change the postions and orientations of the parts in specific ways. So that, when we measure a part's position with respect to absolute cs in the assembly file, and then measure the same part's position in its part file or make the part 'displayed part' againg wrt absolute cs; we see that they are different.
- What I want is to set the part's original position to its assembled one. So that when I open the part in its part file separate from the assembly, I see that it rests in its assembled position wrt absolute cs. How do I do this in the assembly file?

Best regards

 

[ewh]

There may be several ways to accomplish this, none of them simple. Here is the first method I would try: Create a parasolid of each component in the assembly separately. Make a component the displayed part and import its parasolid relative to absolute coordinates. Make all layers selectable and unblank everything. Translate EVERYTHING but the parasolid to the same orientation as the parasolid. Delete the parasolid. Do this for every component not in its proper position. This will mess up any drawings of the components, and they will have to be corrected (basically redrawn).
I look forward to better solutions from other members.

 

[HellBent]

Basically what you want to do is move all of your components (relative to their absolute csys) to the same absolute csys as your assembly. Simply make your component your work part while the csys is oriented to your top-level's absolute. Then with the component as your work part save the csys. Then make the component your work part and do an "Edit->Transform" select "Reposition" as your function. The "CSYS Constructor" menu will pop-up. First select your reference csys (absolute of the component), then select your destination csys (the csys you saved that represents absolute of the assembly). It's going to ask you about transforming any parent geometry which you will want to do. It would be wise to have all your layers and stuff turned on and select everything for the reposition.

Take care....

 

[looslib]

I am against that type of postioning. The reason being that each part stands alone and could be used in multiple assemblies each with its own position.

If you design the parts from with the WCS at absolute in the context of the assembly, then when you save the component it will be in the position of the assembly.

Yes, do the component position BEFORE creating the drawings.

A lot of extra work to move the components after they have been created, as sketches don't like being transformed.




"Wildfires are dangerous, hard to control, and economically catastrophic."
"Fixed in the next release" should replace "Product First" as the PTC slogan.

Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand

 

[HellBent]

Agreed Loosli..but it sounds like he doesn't want it that way. Maybe re-use isn't a concern for him. I do a lot of jobs where re-use isn't a concern....pretty much everything that has any class A surface for example. It's not often that type of part gets re-used in another assembly. Lets say you have a complete drivetrain assembly and all you're doing is the shifter. You try to just work with the transmission file but it's not in body position so you have to open that entire assy and go through the steps listed above to get it into position....just an example of how stuff not being in "body" position can be a real pain.

Take care...

 

[ewh]

I have to agree with Ben. My experience in the aerospace industry is to model everything (except parts used in multiple locations, such as hardware) at aircraft absolute coordinates.
However, the question is how to re-orient after part creation.
I also like hellbents solution of using the wcs to re-orient. Whatever method you use, it is not a quick and easy operation in regards to existing drawings.

 

[HellBent]

I think Ben is saying "not" to model in body position...isn't he?

 

[HellBent]

I made a typo in my first post...the part that reads:
"Then make the component your work part and do an "Edit->Transform""

Should read: Then make the component your DISPLAYED part and do an "Edit->Transform"

 

[sneuri]

How about simply exporting a prasolid of the individual component out of the assmbly file then importing it into the component file? (Make sure your WCS is set to absolute before exporting and importing to retain the relationships). Put the parasolid on a separate layer as reference data.

 

[HellBent]

I do big die cast molds, it's common for an assembly to exceed 700mb. You have to goto assembly structures just to be able to work with them. Having everything in one file is just too slow. Part in one file....trim sheets in another file wavelinked to the components to trim...etc, etc. Are you using Mold Wizard or are you doing sand/wax castings? If so, you're locked into the assembly structure regardless. If arranged properly the files can be really easy to work with. Reference sets are your friend. In slides for example you can have "extended" and "retracted" reference sets. In your master trim sheet file you can have "cover trim" and "ejector trim" reference sets.

One of the other members here does a lot of casting work. You can see a general outline of his modelling practices donw near the bottom of the thread here:

http://www.eng-tips.com/viewthread.cfm?qid=138648&page=1

Take care...

 

[Drkwing]

First of all, thank you very much for your help. I really appreciate it.

The question about why such a need...I am also in the aircraft industry (though fairly new). As ewh stated, everything (except parts used in multiple locations, such as hardware) is modelled at aircraft absolute coordinates and no mating relations are used. This is good so far, but what if I want to use an existing component in a new assembly? In this case that part was modelled corresponding its position and orientation in the original assembly. But in the new assembly that it will be used, its position and orientation will be different. What do we do in this case?

I tried Hellbent's solution. But using the assembly base part's wcs and then transform->reposition does not work for me. It seems reposition only changes position not orientation. So the part still needs orientation.

I also used importing parasolids to the part. ewh said "Translate EVERYTHING but the parasolid to the same orientation as the parasolid", but how can I do this easily?

Regards

 

[looslib]

Yes, I did say NOT to use assembled condition for individual parts.
You have just discovered why I don't like assembled condition for the components, multiple uses. Put the component at absolute WCS and then use mating conditions in your assemblies.
Our UG designers have 'grown up' with this rule, put our Pro/E users refuse to use it. The Pro/E users like to be able use automatic mates to put their assemblies together. They claim it saves them time. The warranty cost per machine on our Pro/E designed machines is 6-8 times the cost on our UG designed machines.

To actually do it, put the parasolid import body on a different layer, then select all except that layer, then translate/orientate.


"Wildfires are dangerous, hard to control, and economically catastrophic."
"Fixed in the next release" should replace "Product First" as the PTC slogan.

Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand

 

[HellBent]

Again..different methods should be used depending on what you're working on. You wouldn't want an entire car, plane, etc. with everything modelled at it's own zero. Imagine trying to put all that data together from outside suppliers, etc. That's why the automotive companies require everything to be in car position from their suppliers.

Drkwing....I'm not understanding what not's working with the reposition. You say it's not "orienting"? That csys based reposition should be putting it to whatever orientation it's in at the upper assembly level. Once done though it may have to be "repositioned" in the assembly...depending on the method it was originally positioned with, i.e. mates or no mates.

Take care....

 

[sneuri]

I guess I should have been more explicit in my suggestion. Like Hellbent said "Reference Sets are your friend". Add and reposition your component part in the assembly file. Then, make sure the WCS is set to absolute in your assembly and export a parasolid of the positioned component. Make the component the displayed part, verify that the WCS is at absolute and import the parasolid back into your component file (on a new layer). Create a new reference set of that parasolid, name the reference set so that you can identify it. Then you can simply reposition that component in your assembly to the absolute coordinates and replace the reference set with your new one. Hellbent's earlier suggestion about saving coordinate systems and repositioning to them will maintain a parametric reference set. Sometimes you're better off doing a quick and dirty copy than spending a week and a half positioning one bracket in a new application.