Part Builder Problem: Custom Parts

[SSato54]

I've been having some problems with designing a custom structure using part builder.  I'm fairly new to civil 3d and part builder (maybe I'm making an obvious mistake?).  I'm currently working on my first project with c3d...ugh...

I started my pipe network by designing the sewer first.  I created a working model of a sewer manhole structure using part builder.  The part works great when inserted into the c3d drawing. 

After I got my sewer system laid out, I started my water system.   This is where I'm getting stuck…
To start, I opened my sewer manhole structure using part builder and saved it as a water manhole structure.  Without changing any of the structures parameters, I can insert the wmh structure into the drawings without problems.  However, this isnt what I want since I need to change certain size parameters.  Once I start editing the wmh's model parameter the structure stops working.  

Example: I edit just one of the model parameters (frame diameter) and the part stops working. The pipe is split in two when inserting the sewer structure (just like it should), however,  it still shows the pipe's line inside of the structure's boundary.  My Sewer system structures don’t show any lines within the structure's boundary (as if there was a wipeout frame there...i assume this is correct).  Also, the sewer structure does not show up in the profile view (I made sure to draw part in profile view).

All in all, I have some questions:
 1) When editing the dimensions of the structure, do you edit model parameters,  size parameters, or both?   If both, is there an order in which you need to edit these parameters? I noticed my model parameter values don’t jive with the size parameter values.
 2) Could the problem be that I am copying an existing structure to create a new structure?  Might there be something in the xml that is still pointing to the old structure's file that makes everything wacko?
 3)  In Part configuration, does anyone know whats the difference between a 'General Structure', 'Junction Structure', and 'Undefined Part Type'?
 4) From reading through the forums I get the feeling that not many people use part builder.  If so, how do they get the pipe networks working?  Are they sacrificing on the drafting side to allow for a working pipe network? I say 'they' because I assume people who are reading this know how to use part builder 😛

[SethHall]

Does your new water part save and validate without issue?

[SSato54]

Yeah, dont have any problems saving and validating.

[SSato54]

I seem to have done a bonehead mistake. Apparently i had the part builder open while testing my structure. The other error may be that my structure style>model tab>Use simple 3D part was set to sphere; i changed this value to 'Part Defined Shape'. This fixed a bunch of problems, however, now my profile view is showing a manhole with a diameter of 12'...back to the drawing board.