# Strange physics behaviour with spring joints and side walls.

Hi.

I have a strange behaviour with my spring joint and physic scene. In my scene there is a spring which is forced downwards by two creates. Works good, but if the creates touch the wall (end of level with collider with no friction physic material) then some of the force of the crates seem to be transmitted into the wall, as the spring will move upwards.

I attached an image to show whats the problem is:

-click-

Has anyone a hint what there is happening in the background of the physic engine and how I could remove this? It’s simply weired to see the spring on two different heights with both times equal weight on it. Seems to me like a bug.

Thx for help!

How is the spring joint connected to the crates? Is there some kind of platform underneath them or is it a more complicated arrangement than that?

Hi.

The spring joint is on the same gameobject as the platform with the rigidbody. The crates are only on the platform itself. The wall right has only a collider that the crates couldn’t fall out of the level.

Hirarchy is:

• Root
— Platform (Components: Rigidbody, Collider, Spring Joint)
— Crate1 (Components: Rigidbody, Collider)
— Crate2 (Components: Rigidbody, Collider)
— WallRight (Components: Collider)

Now, how could the wall take some of the weight (gravity force) of the crates when they are only touching them? If I move the crates only onto the platform, not touching the wall anymore, then the platform moves down again (taking the full weight again).

I have create a little scene to show my problem.
If you open the project, you can click near the red crates to move them.
The green walls will take weight from the crates ontop of the spring (the white box) if they touch them. If both crates are in the middle of the spring they will force the spring down most.

Maybe someone can look at it and try to find a flaw in my scene!?

575539–20525–\$SpringTest.zip (71.8 KB)

Well… anybody could at least confirm the problem? I send this problem to the support too. Maybe they could help and find a solution.

I can confirm that this happens but I’m not sure what is causing it.