[Pat Roche]

I agree with the above posts saying that you are under constrained. Many people, however don't understand why you need to fully constrain your part. The main reason you constrain off the origin is that it allows you to constrain your assemblies easier. Rather than constraining off a side you can constrain off your planes which allow for easier changes (and alot less mental math) later. Also doing this allows easier use of the parameters feature in Inventor. Parameter allow you easily change dimensions of a part and when based off the origin it just gets easier. The easiest way to constrain your part is to go into the 2-D Sketch Panel>Project Geometry then click the two axis you want from the origin tab of the model panel. All thats left is to dimension your part off that.

Hopefully that was helpful,


-Pat