how to modify duct fittings?

[PaulDraftsman26]

I am using MEP 2010. the stock 90 degree rectangular mitered elbow comes in with a 2" throat. I need that to be 6". I went into the content buidler of the part, but i dont understand all the equations. I would really appreciate any help on this or what you have done.

thanks

[Keith.Brown]

Open the fitting back up in the content builder and bring up the size parameter dialog by right clicking on size parameters on the palette and choosing Edit Calculations.  Once there click on the value in the L1 column to bring up the calculation assistant.  Once in the calculation assistant change the value at the end from 2.000 to 6.000.  This will change both the inlet and the outlet values at the same time.  This is because the value for L2 is set to equal the value for L1.  See the picture below.  Make sure to hit ok and save the part.  Your new part should be immediately available for insertion.  If you would like to keep the old part and the new one, make a copy of the old part with the catalog editor first and edit the copy and not the old one.  You will have to give it a new name in order for it to show up in the catalog.  Hope this helps.