# Zero reaction moment when reading from ROT NODE in 2D

**URL:** <https://calculix.discourse.group/t/zero-reaction-moment-when-reading-from-rot-node-in-2d/1312>\
**Category:** Uncategorized\
**Created:** [November 2, 2022, 3:41pm UTC](https://calculix.discourse.group/t/zero-reaction-moment-when-reading-from-rot-node-in-2d/1312 "2022-11-02T15:41:09Z")\
**Posts on this page:** 1\
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**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\
**Post date:** [November 4, 2022, 12:08pm UTC](https://calculix.discourse.group/t/zero-reaction-moment-when-reading-from-rot-node-in-2d/1312/9 "2022-11-04T12:08:23Z")

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> [@Disla](#):
>
> ¿Which is the value of the contact pressure?.

CPRESS is low but not zero. The mesh is very coarse for now so I assume that this output can be improved significantly once I refine the mesh.

> [@Disla](#):
>
> You can stablish the contact but if there is no resistance there will be not reaction.

In a 3D case I get a significant reaction moment (229088.3 Nmm) and I also get it in a 2D case in Abaqus.

How would you add resistance in my case ? Unfortunately, torsional springs aren’t available in CalculiX ([Torsional Spring - SPRING2?](https://calculix.discourse.group/t/torsional-spring-spring2/889)). I could fix the rotation of the driven (larger) gear but I would like to simulate the actual motion. Fixing one gear will make it too stiff when compared with real operation.

> [@Disla](#):
>
> ¿Do you have the pmx file?.

Sure, here it is (from PrePoMax v1.3.5):  
[https://www.dropbox.com/s/ar76ig7oq8fj407/Gears%202D.pmx?dl=0](https://www.dropbox.com/s/ar76ig7oq8fj407/Gears%202D.pmx?dl=0)

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