lances moving in sheetmetal flat layout

I modelled an enclosure with some lances on a edge flange. I created
a plane offset from the top of the flange 0.807" and created my lances
on this plane. When I "flatten" my sheetmetal part - the lances have
moved 0.065. This planar offset has changed. I inserted the
sheetmetal feature after finishing modelling - (I guess creating this
problem) but why would my offset change? I created this offset from
the top of the flange - it should not matter what radius I am using to
create the bend? I guess I am missing something here?

The planar offset stays the same (in the flat)if you create a
sheetmetal part from the get go. Why the difference?

 

i can't visualize (planar offset from top of flange???) your description.
sounds like it's unnecessary. anyhow, lances are usually applied "directly"
to the face of the desired flange. the location (x,y) of the lance is
controlled with dimensions.

 

Just guessing here...

Is the lance dimensioned to a bend? When it is flattened it may be updating
the feature because the bend (or feature on the other side of a bend) has
moved.

Check the relations and dimensions in the sketch for the lance that locates
it.

Todd

 

In hindsight, yes that would be easier - but I wanted the ability to
change the relationship between the lance and the edge of the flange
easily (without linking dimensions).

I could offer my model - I realize my description is hard to
visualize.

Turk