Multiple Hinges in Assembly 2

[ssmithdigilab]

Is there a way to mate two hinges to a door and frame in such a way that when the door swings, the second hinge follows?

For your reference the two hinges are two separate sub-assemblies that are essentially mirror images of each other. I set the sub-assemblies to flexible and mated the first hinge to both the door and the frame. However, Solidworks won't let me mate the second hinge to both the door and the frame. It always tells me that it is overdefined. So I end up solely mating the second hinge to one or the other.

When I move the door one hinge works perfectly, but the second hinge doesn't turn and either ends up interfering with the door or the frame (depending on which one it is mated to).

I've searched pretty extensively on this site for info about hinges and can't find any answers to this particular problem. It seems to me that it would be pretty common to have more than one hinge on a door and that you would need to be able to mate all hinges to both the frame and the door for the motion to be portrayed correctly.

 

It was in the hinge assembly.
I have removed the Limit mate and mated the second hinge to the first instead of both to my doors. If I go to assembly tab and use "move component" and set it to collision detect, stop on collision it seems to work o.k. Before I was just left clicking on component and moving it. It seems impossible to not over-constrain with a limit mate no matter what I do.

 

"Tempermental" hahaha. That is the best way to describe Solid Works in general. I started with Cadkey version 17 and have had a hard time with my transition over to Solid Works. I guess you prefer what you start on.

 

[ssmithdigilab]

What I ended up doing was creating a hinge mate in the hinge assembly with max and min values for the angle. Then in the door assembly I assembled one hinge to both the door and frame and set it to flexible. The other hinge was mated just to the door, but also set to flexible. Unfortunately, the assembly becomes over-constrained if you try to mate the second hinge to both the door and frame. Makes no sense, but that is reality. You can, however, still make it "appear" to function correctly.

The key to this is to orient your hinge assembly model in the same orientation as the closed position in the door assembly. The rotation of the hinge in the hinge assembly must also be the same as it would be in the door assembly. In other words, one half of the hinge will be mated to a plane in the hinge assembly, with the other half able to move. The half that's mated to the plane in the hinge assembly must be the same half that would be mounted to the frame in the door assembly (if SolidWorks would allow that).

In the door assembly, when you grab an edge of the door and swing it open, the first hinge will work as it would in real life. Since the second hinge is only constrained to the door, it will rotate with the door. The half of that hinge that would be mounted to the frame in real life stays in the same orientation it has in the hinge assembly model. Therefore, even though it isn't mated to the frame, it appears to be.

 

[ShaggyPE]

Do you really need it to be flexible? My guess is no. During your preliminary design studies... sure flexible is nice so you can confirm that nothing interferes. During this time, just suppress the second hinge... or don't put it in in the first place. Once you know your door is good, add the hinge.

Within the hinge assembly, create a few configurations. Open, Closed, and XX degrees. Create configs in your upper assembly if you desire. This will also allow you to lock down your door angle for the purposes of drawings etc.

-Dustin
Professional Engineer
Pretty good with SolidWorks

 

[ssmithdigilab]

Whether or not you need both hinges to be flexible is irrelevant. The fact of the matter is SolidWorks has this flexible feature, so you should be able to use it if you want to. It makes no sense that you can't have two flexible hinges in an assembly with the hinges mated to both the door and the frame. It is very common for doors to have two hinges.

 

I think so to. It messed with that whole assebly. I finally just created two config's. One open and one closed, so that everything was solved and the file would be happy. That goes back to the above statement, Solid Works is very tempermental. Right now I don't have any red, so it is happy Solid Works.

 

[ShaggyPE]

Having things flexible just adds complexity to the model which in turn slows down rebuilds and introduces opportunities for errors. Getting it to a point where you can eliminate the flexible situation was all I was suggesting.

-Dustin
Professional Engineer
Pretty good with SolidWorks