# Allow the use of user defined Coordinate Systems for gravity load

**URL:** <https://prepomax.discourse.group/t/allow-the-use-of-user-defined-coordinate-systems-for-gravity-load/3793>\
**Category:** Feature Requests\
**Created:** [October 29, 2026, 9:26am UTC](https://prepomax.discourse.group/t/allow-the-use-of-user-defined-coordinate-systems-for-gravity-load/3793 "2026-10-29T09:26:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![abelvelascovilanova](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/abelvelascovilanova/32/9244_2.png) [@abelvelascovilanova](https://prepomax.discourse.group/u/abelvelascovilanova)\
**Post date:** [October 29, 2026, 9:26am UTC](https://prepomax.discourse.group/t/allow-the-use-of-user-defined-coordinate-systems-for-gravity-load/3793/1 "2026-10-29T09:26:42Z")

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Currently only some loads allow user defined coordinate systems, like surface traction.

Thanks,

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**Author:** ![FEAnalyst](https://yyz2.discourse-cdn.com/free1/user_avatar/prepomax.discourse.group/feanalyst/32/688_2.png) [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\
**Post date:** [October 29, 2026, 11:04am UTC](https://prepomax.discourse.group/t/allow-the-use-of-user-defined-coordinate-systems-for-gravity-load/3793/2 "2026-10-29T11:04:50Z")

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User-defined coordinate systems internally rely on the CalculiX’s `*TRANSFORM` keyword which changes the coordinate systems of the selected nodes from global to local and thus it only affects nodal forces and constrains (BCs, MPCs). For other kinds of loads, it would have to be realized differently (in the case of gravity, it would require converting the input to gravity vector’s components (now it needs to be done manually if you want to apply gravity not aligned with the global axes).