Compare imported parts

david_scott949

Hi, 
I have two versions of the same part in STEP format.  I've imported them but obviously they are in separate part studios.   Is there a way to compare the two parts ? 

NeilCooke

Yes! Use the Derived feature to add the other version to your current part studio. 

For an even better comparison you can do this:

1. Use the Delete Part feature to remove the first version of the part from the part studio 
2. Use the Derived feature to add the next version of the part to the current part studio
3. Use the Compare tool (in the versions and history flyout) to get a graphical comparison of the two document timestamps 

david_scott949

Cool.  Where's the Derived feature?  Never used that before. 

david_scott949

ignore that... found it  

brian_brady

NeilCooke said:

Yes! Use the Derived feature to add the other version to your current part studio. 

For an even better comparison you can do this:

1. Use the Delete Part feature to remove the first version of the part from the part studio 
2. Use the Derived feature to add the next version of the part to the current part studio
3. Use the Compare tool (in the versions and history flyout) to get a graphical comparison of the two document timestamps 

@NeilCooke is there a way to compare multiple imported or derived parts within the same document. Say I have imported or derived solid parts created elsewhere (on a different system) and want/need to remodel them in Onshape so they have a complete feature tree. Is there an easy way to compare the finished parts that were created using Onshape to the original dumb solids? Your above response leads me to believe you were talking about a document with a single part in a single part studio being used by a single person. What I'm wondering is if it can be done easily (that's the key word) for a document with multiple parts, multiple part studios, possibly assemblies, and multiple persons working on the document. If there is not a tool yet, is this something that can be created with a feature script?

NeilCooke

@brian_brady I'm not sure if the number of parts/part studios/users makes a difference. Assemblies cannot use the compare tool, unless you do some in-context hack. Whenever I have remodelled something, I have just had the original as an import feature and just hidden it when I need to - you can then use the compare method I mention above. FS may well be limited as a solution. I get the feeling I am missing something here?

owen_sparks

@brian_brady This sounds a lot like automated grading of a student's work.  Compare each submitted doc to your master answer doc and generate a list of differences in one hit.

OwS

brian_brady

NeilCooke said:

@brian_brady I'm not sure if the number of parts/part studios/users makes a difference. Assemblies cannot use the compare tool, unless you do some in-context hack. Whenever I have remodelled something, I have just had the original as an import feature and just hidden it when I need to - you can then use the compare method I mention above. FS may well be limited as a solution. I get the feeling I am missing something here?

You mentioned comparing points in the history timeline. I was just wondering if there are a lot of parts, part studios, and assemblies is this still feasible to do. I did a quick check with a single part and I don't think the current compare feature is what I want or need. I would like to know that the designer (or student) made the new part exactly like the dumb solid; i.e. if a boolean subtract was done there would be nothing left. I have had graduates doing this kind of work at various companies early in their careers; where they have to create new models that exactly match old or supplier provided dumb solids from other systems. It would be nice if there was an easy way to verify that features were not missed and there was an exact match.

brian_brady

owen_sparks said:

@brian_brady This sounds a lot like automated grading of a student's work.  Compare each submitted doc to your master answer doc and generate a list of differences in one hit.

OwS

Wouldn't that be nice. ;-)

dean_brettle

I realize this is a really old thread, but since I came across it while searching for a solution before implementing my own, I thought I'd follow up. I recently created a custom Compare feature that can be used to compare parts, including imported parts. If there are differences, it will create composite part(s) containing them. Among other things, this can be used to help grade student work or to allow them to self-assess.

romeograham

Another way to easily tell if a part or assembly is correct is employed by the Onshape training and certification materials.

Use the location of the Center of Mass or the Mass of a part or assembly. If the materials and geometry are precisely correct, the COM or Mass will be correct. It could be the first thing that you check...if that is correct, then you move on to the more labour-intensive grading levels...