Split or trim ellipses without destroying drawing functionality.

[griff701]

Hi,

 

I'm a student and have the task of modelling a spanner, that changes proportions depending upon the distance specified for the jaw opening. (Distance AF)

 

I have a drawing that works perfectly (as far as I can tell) - If the AF distance changes, everything else updates.

 

How can I convert the 3 marked lines in the drawing into construction geometry (so I'm left with the coloured area) without it destroying the functionality?

 

I've tried splitting the lines (that results in unconstrained geo and it doesn't update properly), trimming them (that failed as well), and even building the entire drawing in construction geometry and trying to convert the bits I want to keep.

 

Am I missing something really obvious?

 

Thank you.

 

 

(Highlighted area is mine)

spanner12a.ipt

[SLW210]

I moved your thread to the Autodesk Inventor Forum, please post Inventor questions, there.

[griff701]

Sorry - I thought I had. (When I hit 'submit' the forum decided I wasn't logged in after all. I Refreshed the page and must have gone back a level)

[kpyoung333]

At first glance I would say you can break the ellipse lines at their center intersections (make sure they still have the tangent constraints on, check by F8, also check Show All Degrees of Freedom and make sure that it is full constrained), turn them into construction lines, then you might have to right click on the segments and CLOSE LOOP and choose the area lines you want. A lot of times when I draw complex extrusions I have to close loops or delete the Project Geometry (Project Cut Geometry is especially unfriendly when trying to do extrusions and revolves). Once you get it working you can set up your iLogic Form (make sure in VIEW>User Interface>iLogic Browser>Check Box: ON) for easy manipulation of your constraints.

[griff701]

Its 2.00am and I still cant get things to work - but I wanted to say thanks for your time.

 

Every time I try to do something I get either 'Failed to split curve', 'Adding this restraint will over define the drawing' or 'Constraint already exists'. I tried closing the loop to be told 'a coincident restraint is missing, would you like to add it?', selecting 'yes' gives.........'Adding this restraint will over define the drawing' haha

Edited January 23, 2015 by griff701