Autodesk Revit MEP

[#1]

Perhaps someone can explain to me on why the out of the box generic welded elbows aren't as customizable as they should be?  If the elbow is 90 degrees, it appears to be a short radius elbow.  However, if the elbow is acute (less than 90 degrees), the elbow has a longer turn radius.  It also appears to have a varying turn radius as the angle changes --- which I don't really understand.  I've had to copy/paste/modify the out of the box family to get elbows with a turn radius that can be controlled by user (instance parameter) and change a few other parameters.

It's not something new, but I've never really understood this.

[#2]

Architects designed the mechanical systems and the various bits and pieces. The why I have never understood, either. Sent from my iPad

[#3]

I posted something similar to this, a few weeks ago.  I noticed some of the PVC drain elbows had a different sweep at certain sizes.  The problem is in the out-of-the-box look-up tables.  I had suspected that other families had this problem as well.  I had to modify the look-up table and distribute that to my users.  That complicates the software mantenance process.  I will have to look into your solution. 

[#4]

The problem is in the out-of-the-box look-up tables.  I had suspected that other families had this problem as well.  I had to modify the look-up table and distribute that to my users.

I am not sure it's the data in the look up tables that is incorrect --- or at least that's not the only thing.  The fitting outer diameter values in the look up table are close to REVIT's default values for a schedule 40 carbon steel pipe.  The formula for the turning radius varies with the angle.  This occurs with the default pvc elbow as well.