assembly degrees of freedom

jonathan_mizrahi827

Is there a way to see if an assembly is fully constrained, and if it's not, to identify its degrees of freedom?

viru

@jonathan_mizrahi827, I think you are looking like degrees of freedom analyzer available in Autodesk inventor. Currently this facility is not available in Onshape. You can raise improvement request for this. In near future we hope that this facility will be provided by Onshape.
Autodesk Inventor:- Whenever you apply a constraint to a component in an assembly, you remove one or more degrees of freedom. A component is fully constrained when all degrees of freedom (DOF) are removed. You are not required to constrain completely any component in an assembly in Autodesk Inventor.

To verify the DOF of components in an Autodesk inventor assembly we can check by two method.

• Select Degrees of Freedom from the Visibility panel of the View tab.
• Drag a component in the graphics window. Other components in the assembly move, based on existing constraints.

Tony_C_

Click the "limit" button when setting a mate.

Tony_C_

Sorry, I read that wrong.  If you want to see how much items can move within the limits of a mate click the play button ">" and it will animate.

noa

@jonathan_mizrahi827 , while there is no "click to check if my assembly is fully constrained" button, you can animate the entire assembly and visually see the degrees of freedom allowed. The play button within a mate dialogue as @tony_castongia's mentioned will only animate that single mate. If you right click a mate after it is applied and then click "Animate," it will animate that mate and any others those parts are included in. This is a good way to visualize your assembly's overall motion and, indirectly, it's degrees of freedom. Note, however, that the animate command only animates one of a mate's possible degrees of freedom. A pin and slot mate, for example, has two (translate in x, rotate about z) but when you go to animate it, you must choose one.

Hope this helps,
Noa

jonathan_mizrahi827

Thanks for the help. It looks like that only works on the level of a single mate. For example, if I have two parts connected at two holes by two revolute mates (or revolute + cylindrical), the parts are fully constrained. However, if I animate either revolute mate, it will spin the part about the hole.
More generally, if I have a large assembly consisting of many parts and many mates, it would be very helpful to be able to see, across the entire assembly, where it is not constrained.

viru

@jonathan_mizrahi827, I think you are looking like degrees of freedom analyzer available in Autodesk inventor. Currently this facility is not available in Onshape. You can raise improvement request for this. In near future we hope that this facility will be provided by Onshape.
Autodesk Inventor:- Whenever you apply a constraint to a component in an assembly, you remove one or more degrees of freedom. A component is fully constrained when all degrees of freedom (DOF) are removed. You are not required to constrain completely any component in an assembly in Autodesk Inventor.

To verify the DOF of components in an Autodesk inventor assembly we can check by two method.

• Select Degrees of Freedom from the Visibility panel of the View tab.
• Drag a component in the graphics window. Other components in the assembly move, based on existing constraints.