Adaptivity Issues in Assembly

[david.reed.tosoh]

I am just starting to learn the adaptivity feature in Inventor 13.  I watched some videos and can successfully make a spring which compresses in an assembly, and a metal rod which expands radially and shortens as it is compressed along its axis.  Next, I would like to model compressing a rod radially between two dies (which results in an increase in length. 

I create the rod.  Set diameter to "DIAMETER=5" then extrude the cylinder to a length of "LENGTH=10+(5-DIAMETER)"   therefore a one inch length increase for each loss of 1" of diameter.  Then i right click on the extrusion in the browser window and select adaptvitiy.  At this point I can change the diameter in the sketch, hit finish sketch and the length of the part updates accordingly with the new diameter.

Next i create two flat plates and place them into an assembly and completely constrain them with 6 inches between their faces, (1" more than my diameter).  I place the adaptive cylinder into this assembly, right click, select adaptivity, constrain one plate to the cylinder tangentally.  When I go to constrain the other plate tangentally it immediatly gives me the assembly canot be solved dialogue. 

With the spring, it would just jump up to the other plate regardless of the distance.  Im expecting the diameter to increase to 6" and the length to shorten but its not working.  Any ideas?

[coreyparks · Accepted solution]

See the attached files.  I did it like the spring drawings I have seen.  I don't believe adaptivity and Tangents always work so well together.

[david.reed.tosoh]

Thank you!  This is exactly what I needed.  I agree, I thought I was creating the billet similarly to the spring but eveything seemed to go haywire once I began to constain it.  Now I noticed you did it using sheet metal parts for the plates.  I am not as familiar with sheet metal, I could substitute out the sheet metal faces for regular .ipt blocks with the same constraints and it should still work correctly??  (meaning the part being sheet metal has nothing to do with its adaptibility and dimension change during the drive)

[coreyparks]

The sheetmetal parts should have no bearing on the overall design.  I just tend to create all of my flat plates that way cause the material thickness then shows up in my title block automatically :-).

[david.reed.tosoh]

Well played! Thanks again!