Consider the derived part to be a "dumb" (look Mech, quotes!) solid like a
imported SAT or STEP. If you want to change the basic structure of the part
you change the base part and the derived part updates to reflect these
changes. You can add new features (cuts or joins) but not edit them
directly.
The Edit Base Feature command are used to move and remove faces (stretch and
shrink). To be honest I've never really used them in practice (just playing
around with them)
--
Sean Dotson, PE
http://www.sdotson.com
Check the Inventor FAQ for most common questions
www.sdotson.com/faq.html
"Gary Cross" wrote in message
news:DCE3417042C26068E702AED8F9D33D94@in.WebX.maYIadrTaRb...
> Hi Group,
>
> Can anyone shed some light on this ?
>
> I created a derived part and then tried to change an 'extrude subtract'
> feature in the derived part. But I run into trouble everytime I try to
edit
> the feaure using "Edit base Feature".
>
> The parts are arced tubes that cross over each other & I want to crosslap
> joint them together where they meet. So each will get a half bite in the
> middel taken out, but on opposing sides.
>
> Even if I break the link I cannot change the extrude subtract feature as
> needed.
>
> Maybe I am missing something but, aren't you supposed to be able to
> completely change various features in the derived parts if you want? or
> only add new ones? What are the limitations other than what is stated in
the
> (weak) help files?
> TIA
>
> Gary
> gcross@crossdesign.com
>
>
>
>