Parametric content builder. Fittings

Hi everyone, hope you could help me to eliminate a confusion which may seem to be rather clear thing to hardcore MEP users.

The nature of the issue is the following:

I'm trying to create custom eccentric parametric reduser and i don't want to modify the existing template.

I'm quite new to all this parametric thingies, but i made my concentric custom reducers quite easy in few simple steps: creating 2 workplanes where one of those offsets the other for the length of the reducer which is a "table" type parameter, then creating 2 circular profiles followed by creating a transition between 2 planes and adding connectors.

Now when it comes to eccentric reducer i need to be able to offset the center of minor radius end to a certain value (which is a calculation: D1*0.5-D2*0.2 and D1 and D2 being greater and smaller radius of a reducer respectively). The obvious logical solution is to create a refference point. Say we start drawing the thing from greater radius to smaller. You create cirular profile, representing your greater diamter pipe, draw 2 lines (1 goes from center of profile towards the edge of profile, representing the radius actually, 2 goes from edge towards the center of the smaller radius profile, which is going to be created on offset plane) and the endpoint of the second line is the point we need to reffer to on the offset plane. This refered point defines the center of second circular profile which represents the smaller pipe.

Now the question is how exactly does MEP knows where i want my cirlular profile to be centered (any shape of a profile for tha matter). I cannot define center coordinates manually nor can i demand a specific point to be center of my circular profile (or can i?) therefore i cannot do point reference and entire thing goes bended and twisted.

I was hoping to upload some pictures of drawing process but failed miserably. If none of you guys gets what i'm trying to say - i'll do handdrawings on lunchbreak and try to uplod those.

Thanks in advance.

Apparently the is no real way to create custom eccentric reducer as the content builder does not allow to extrude with eccentricity. The only solution i found is to go to catalog manager, "save as" the eccentric reducer template and put your own numbers into it. Worked fine for me, hope it helps someone.

P.S. As a general notice you should always have a copy of all your default MEP catalogs which normally are at C:\ProgramData\Autodesk\MEP 2011\enu\MEPContent just to be sure you can roll back in case you mess up big time like i did the other day - saves you trouble of reinstalling the entire thing, because "reinstalling components" did not quite work for me.