Adjustable Assemblies

Creator
Creator

I am having a bit of trouble with adjustable assemblies. I seem to having a bit of trouble with the constraints breaking on me.  Can anyone explain if there are constraints you can not use either in the adjustable assembly itself or the higher level?  It seems to not like a center-plane constraint in the higher level assembly.

 

I read in the help file that you need only leave the adjustable assembly unconstrained in the direction of motion desired, so with a hydraulic cylinder I grounded the body.  I then applied an axial constraint between the rod and the body, and then applied a path constraint between the end of the rod(follower) and a sketch in the body.  I had trouble with this and it seemed to not like the ground constraint on the body.

 

Can anyone help with me with some general information on adjustable assemblies?

7 REPLIES

Re: Adjustable Assemblies

Community Manager Community Manager
Community Manager

Just a guess here -- not my area of expertise, but I think adjustable ASMs work by "promoting" the constraint system to the higher level asm. If that is so, then the ground will indeed be a problem. I imagine the body needs to rotate in the context of the higher level ASM and the ground may prevent it from doing so...

Dan Staples
Director, Solid Edge Product Development

Re: Adjustable Assemblies

Phenom
Phenom

(view in My Videos)
To me, what they call an "adjustable part" is really the ability to "Scale" a part along an axis like a spring or a squished O ring.

 

What I do is very adjustable, but takes some gettin used to. I start a part by projecting planes into my first sketch. If you move that plane, the sketch, and as a result, the part changes.

 

This can also be done by projecting parts into other parts sketches (include with acociativity). but beware, never delete the projected edge or the connection is lost forever.

Re: Adjustable Assemblies

Creator
Creator

I believe you are correct Dan,  though I wasn't sure if it was promoting the ground relationship or not since it does not appear in the pathfinder in the higher level.

 

I seem to have gotten my assembly working, though It seems to work whether the body of my cylinder is grounded or not.

 

My trouble may have been a result of angle constraints.  Sometimes I am able to create angle constraints by selecting two planes, and other times it wants an extra plane defined on which the measurement lies.  If that plane is defined I would think it would break the angle constraint in the above situation if the measurement plane doesn't rotate with the other planes.  Is there a particular rhyme or reason for Solid Edge wanting a plane of measurement?  Will it break an angle constraint between two planes if the parts are rotated?

 

I think this was the issue, since my assembly started working after deleting and redefining my angle constraints.

 

Thanks for your response Dan.  Any further help would be appreciated.

Re: Adjustable Assemblies

Creator
Creator

12Gage,

 

Dan is on the right track as far as my problem with Adjustable Assemblies.  Specifically adjustable assemblies in Solid Edge are sub-assemblies that have their constraints promoted to a higher level assembly for solution, allowing an under constrained sub-assembly some freedom of motion in the higher level.

 

Your "Adjustable Part" is pretty neat though.  Very useful.

Re: Adjustable Assemblies

Creator
Creator
For added information if it isn't clear. My model is a simple crane that has a king post, and a boom operated by a cylinder. The crane has slewing about the king post. This creates the situation where I have an angle constraint controlling my boom angle, and another angle constraint for slewing the crane. The adjustable sub-assembly of my cylinder has a couple of axial constraints at either end(one pinned to the king post, the other to the boom) so it just extends or contracts "following" the boom.

Re: Adjustable Assemblies

Community Manager Community Manager
Community Manager

This is what the Help says about this:

 

 

Measurement Plane

Specifies the plane from which the angular relationship will be measured.

If you have previously defined an axial align relationship, this step will be skipped as enough information has been given to define the measurement axis.

If you select planar faces in the Measure-From Element and Measure-To Element steps, this step will be skipped as enough information has been given to define the measurement axis.

In all other instances, a measurement plane must be defined by selecting a planar face.

 

So if you are giving 2 planar faces the angle between them is clear and a measurement axis should not be asked for. Is that what you are seeing?

 

Dan Staples
Director, Solid Edge Product Development

Re: Adjustable Assemblies

Creator
Creator

Hey Dan,

 

Yeah, I think that probably explains what I have been seeing.  I was having so much trouble getting the adjustable assembly working, I may have goofed selecting my entities for the angle constraint the first time.  Thanks for the input.  Sorry I missed something that was in the help file.  I typically like trying to find my answers there before wasting ya'lls time.(This is actually my first time posting questions)

 

I am still not very confident in how I can and should constrain an adjustable sub-assembly before using it in a higher level, so clarification from anyone experienced with them would be helpful. I really appreciate ya'lls help so far.