# Tips & Tricks **URL:** https://prepomax.discourse.group/c/tips-tricks/11.md [Latest](https://prepomax.discourse.group/latest.md) · [Categories](https://prepomax.discourse.group/categories.md) · [Tags](https://prepomax.discourse.group/tags.md) --- ## [About the Tips & Tricks category](https://prepomax.discourse.group/t/about-the-tips-tricks-category/450)
**Author:** [@Matej](https://prepomax.discourse.group/u/Matej)\ **Replies:** 0
A category to share tips, tricks, hints and small utilities that can improve the day-to-day usage of the PrePoMax. --- ## [Tie-constrain is not applying](https://prepomax.discourse.group/t/tie-constrain-is-not-applying/3689)
**Author:** [@JJJ](https://prepomax.discourse.group/u/JJJ)\ **Replies:** 2\ **Last updated:** [September 24, 2026, 9:26pm UTC](https://prepomax.discourse.group/t/tie-constrain-is-not-applying/3689 "2026-09-24T21:26:16Z")
Hi all, I have a model where it seems that tie-constrain is not applying properly )after calculation, I get excesive displacements=. Is it possible to define tie-constraint between a surface and the edge of another surf… --- ## [Install PrePoMax on CachyOS with DPI Fixes](https://prepomax.discourse.group/t/install-prepomax-on-cachyos-with-dpi-fixes/3658)
**Author:** [@cmmcnamara](https://prepomax.discourse.group/u/cmmcnamara)\ **Replies:** 2\ **Last updated:** [September 9, 2026, 12:41am UTC](https://prepomax.discourse.group/t/install-prepomax-on-cachyos-with-dpi-fixes/3658 "2026-09-09T00:41:53Z")
I’ve recently started migrating from Windows to Linux as part of a new company I have started leveraging open source software for all business needs. This has the obvious headaches of getting software to run correctly if… --- ## [Calculix/NX Nastran - pinned lug contact](https://prepomax.discourse.group/t/calculix-nx-nastran-pinned-lug-contact/3562)
**Author:** [@Gunnar](https://prepomax.discourse.group/u/Gunnar)\ **Replies:** 11\ **Last updated:** [July 8, 2026, 5:59pm UTC](https://prepomax.discourse.group/t/calculix-nx-nastran-pinned-lug-contact/3562 "2026-07-08T17:59:58Z")
Hello, I just wanted to post an example comparing results from Calculix and Nastran, as I have the opportunity to test NX Nastran for a limited time for my company. The example shows a simple contact scenario between a … --- ## [Don't apply concentrated force load to surfaces](https://prepomax.discourse.group/t/dont-apply-concentrated-force-load-to-surfaces/1271)
**Author:** [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Replies:** 8\ **Last updated:** [June 3, 2026, 4:26pm UTC](https://prepomax.discourse.group/t/dont-apply-concentrated-force-load-to-surfaces/1271 "2026-06-03T16:26:33Z")
It’s definitely the most common mistake made by new users (especially those who don’t have experience with Abaqus) so let me explain this in detail. TL;DR: Never apply a concentrated force load to a surface unless you a… --- ## [Output result on Axisymmetric cylinder](https://prepomax.discourse.group/t/output-result-on-axisymmetric-cylinder/3486)
**Author:** [@Nemo](https://prepomax.discourse.group/u/Nemo)\ **Replies:** 4\ **Last updated:** [May 20, 2026, 9:08am UTC](https://prepomax.discourse.group/t/output-result-on-axisymmetric-cylinder/3486 "2026-05-20T09:08:32Z")
When you make an axisymmetric analysis, you can chose two way to have the output result : in 2D or in 3D. The way to have the result change between the two settings. For example I juste make a simple analysis on a 10 mm … --- ## [getResultsFromFRD.py : Extract Results from PrePoMax/CalculiX](https://prepomax.discourse.group/t/getresultsfromfrd-py-extract-results-from-prepomax-calculix/2270)
**Author:** [@mhayrettin](https://prepomax.discourse.group/u/mhayrettin)\ **Replies:** 5\ **Last updated:** [April 30, 2026, 6:26am UTC](https://prepomax.discourse.group/t/getresultsfromfrd-py-extract-results-from-prepomax-calculix/2270 "2026-04-30T06:26:10Z")
Hi, First of all thank you all for your contributions to open source FEM . If you need to get: Undeformed node locations Nodal Displacements Nodal Stress Tensor Nodal Strain Tensor Nodal Forces to work with, so you … --- ## [Simple tutorial on how to divide an object in FreeCAD into PrePoMax](https://prepomax.discourse.group/t/simple-tutorial-on-how-to-divide-an-object-in-freecad-into-prepomax/3229)
**Author:** [@MisiaKu](https://prepomax.discourse.group/u/MisiaKu)\ **Replies:** 24\ **Last updated:** [February 1, 2026, 8:59pm UTC](https://prepomax.discourse.group/t/simple-tutorial-on-how-to-divide-an-object-in-freecad-into-prepomax/3229 "2026-02-01T20:59:05Z")
For a cuboid to have a cubic net, it must be divided into simple parts. The transfinite gmsh setup can always be defined on solid parts with 5 or 6 faces. Therefore, the division of the cuboid must be different … --- ## [Structural meshing for compounds + Mesh Refinement - works well :)](https://prepomax.discourse.group/t/structural-meshing-for-compounds-mesh-refinement-works-well/1363)
**Author:** [@Gunnar](https://prepomax.discourse.group/u/Gunnar)\ **Replies:** 14\ **Last updated:** [January 28, 2026, 8:02am UTC](https://prepomax.discourse.group/t/structural-meshing-for-compounds-mesh-refinement-works-well/1363 "2026-01-28T08:02:56Z")
Starting from v2.0.2, I am just impressed how good structural meshing now works with the new Mesh Refinement for compounds. I would like to share some positive observations, using a bolt-model as example: The CAD model … --- ## [3D Interactive Analysis Stress Viewer](https://prepomax.discourse.group/t/3d-interactive-analysis-stress-viewer/3111)
**Author:** [@Mehmet](https://prepomax.discourse.group/u/Mehmet)\ **Replies:** 11\ **Last updated:** [December 7, 2025, 12:21am UTC](https://prepomax.discourse.group/t/3d-interactive-analysis-stress-viewer/3111 "2025-12-07T00:21:31Z")
Hello Prepromax Community, This is my first post…I am sharing the Analysis Stress Viewer I developed to easily share and examine analysis results. I am not an expert analyst, I am mechanical designer; I only use simple… --- ## [CPU Benchmark Study PrePoMax vs Commercial FEM and PrePoMax Tutorials](https://prepomax.discourse.group/t/cpu-benchmark-study-prepomax-vs-commercial-fem-and-prepomax-tutorials/3115)
**Author:** [@hnrwagner](https://prepomax.discourse.group/u/hnrwagner)\ **Replies:** 9\ **Last updated:** [December 4, 2025, 8:41am UTC](https://prepomax.discourse.group/t/cpu-benchmark-study-prepomax-vs-commercial-fem-and-prepomax-tutorials/3115 "2025-12-04T08:41:52Z")
Over the last weeks I have been testing PrePoMax / CalculiX extensively and performed a benchmark study against Commercial FEM. Regarding CPU scaling, I uploaded the full results to my YouTube channel, but in short: F… --- ## [PrePoMax in the RR3 Wind-Turbine Tower Benchmark (Sadowski Round Robin 2024–2025) – Results & Observations](https://prepomax.discourse.group/t/prepomax-in-the-rr3-wind-turbine-tower-benchmark-sadowski-round-robin-2024-2025-results-observations/3049)
**Author:** [@hnrwagner](https://prepomax.discourse.group/u/hnrwagner)\ **Replies:** 49\ **Last updated:** [November 20, 2025, 11:36am UTC](https://prepomax.discourse.group/t/prepomax-in-the-rr3-wind-turbine-tower-benchmark-sadowski-round-robin-2024-2025-results-observations/3049 "2025-11-20T11:36:09Z")
Hi everyone, I recently completed my participation in the RR3 Tower Finite Element Benchmark (Part 3 – Software Survey), organized by Dr Adam J. Sadowski (Imperial College London) as a continuation of the well-known Rou… --- ## [Known CalculiX limitations](https://prepomax.discourse.group/t/known-calculix-limitations/3050)
**Author:** [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Replies:** 4\ **Last updated:** [November 4, 2025, 12:11pm UTC](https://prepomax.discourse.group/t/known-calculix-limitations/3050 "2025-11-04T12:11:50Z")
Here’s a list of the most important limitations of the CalculiX solver, particularly the undocumented ones. Some can be considered recurring bugs, while others are just unimplemented functionalities (not missing features… --- ## [Procedure to model plastic behavior using material data from tensile test](https://prepomax.discourse.group/t/procedure-to-model-plastic-behavior-using-material-data-from-tensile-test/1388)
**Author:** [@FdoLorenzo](https://prepomax.discourse.group/u/FdoLorenzo)\ **Replies:** 10\ **Last updated:** [June 27, 2025, 2:04pm UTC](https://prepomax.discourse.group/t/procedure-to-model-plastic-behavior-using-material-data-from-tensile-test/1388 "2025-06-27T14:04:48Z")
I have read questions from users as to how to model plastic behavior in Prepomax and thought that I can contribute a little bit. The analysis in this post comes from one of my Professors at the University of Michigan Jos… --- ## [Stress/displacements according to cylindrical coordinates system](https://prepomax.discourse.group/t/stress-displacements-according-to-cylindrical-coordinates-system/2786)
**Author:** [@Paul18fr](https://prepomax.discourse.group/u/Paul18fr)\ **Replies:** 1\ **Last updated:** [June 20, 2025, 8:40am UTC](https://prepomax.discourse.group/t/stress-displacements-according-to-cylindrical-coordinates-system/2786 "2025-06-20T08:40:59Z")
Hi Once again i’ve tested how PrePomax is “user friendly”; even if i’ve no doubt about the accuracy of the interface, i wanted to test a well known test case: a thick cylinder under pressure. Equations for the radial/t… --- ## [MbDFEM: Combining Multibody Dynamics and Finite Element Method](https://prepomax.discourse.group/t/mbdfem-combining-multibody-dynamics-and-finite-element-method/2607)
**Author:** [@aiksiongkoh](https://prepomax.discourse.group/u/aiksiongkoh)\ **Replies:** 2\ **Last updated:** [April 15, 2025, 8:45pm UTC](https://prepomax.discourse.group/t/mbdfem-combining-multibody-dynamics-and-finite-element-method/2607 "2025-04-15T20:45:56Z")
Hi: Jose Egas and I have been working on combining Multibody Dynamics and Finite Element Method inside FreeCAD. Our initial results are shown at https://forum.freecad.org/viewtopic.php?t=96007 We would appreciate your… --- ## [Slippage at Press Fit Connection](https://prepomax.discourse.group/t/slippage-at-press-fit-connection/2597)
**Author:** [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Replies:** 0\ **Last updated:** [April 1, 2025, 6:49pm UTC](https://prepomax.discourse.group/t/slippage-at-press-fit-connection/2597 "2025-04-01T18:49:42Z")
This is a recent test I made with prepomax looking for the maximum torque allowable at an interference fit before slippage. Results are fine below a 2% deviation of expected values. --- ## [Development of multilingual version](https://prepomax.discourse.group/t/development-of-multilingual-version/2490)
**Author:** [@yozoyugen](https://prepomax.discourse.group/u/yozoyugen)\ **Replies:** 0\ **Last updated:** [February 21, 2025, 5:33am UTC](https://prepomax.discourse.group/t/development-of-multilingual-version/2490 "2025-02-21T05:33:48Z")
I tried to make multilingual version for PrePoMax. Some of GUI components can be shown in Japanese (or English) I made templates (Japanese example), so you can make your language version. I hope it will be useful for… --- ## [Open source FEM – shell calculations](https://prepomax.discourse.group/t/open-source-fem-shell-calculations/1048)
**Author:** [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Replies:** 1\ **Last updated:** [August 27, 2023, 10:10pm UTC](https://prepomax.discourse.group/t/open-source-fem-shell-calculations/1048 "2023-08-27T22:10:50Z")
Found this post on the net which I think is not properly solved. It is based on NAFEMS LE3: HEMISPHERICAL SHELL linear elastic benchmark. Prepomax result is 185.1mm compared to expected result 185mm. HEMISPHERICA… --- ## [Silo modeling (for fun and to dig into PrePoMax)](https://prepomax.discourse.group/t/silo-modeling-for-fun-and-to-dig-into-prepomax/2366)
**Author:** [@Paul18fr](https://prepomax.discourse.group/u/Paul18fr)\ **Replies:** 6\ **Last updated:** [January 7, 2025, 4:07pm UTC](https://prepomax.discourse.group/t/silo-modeling-for-fun-and-to-dig-into-prepomax/2366 "2025-01-07T16:07:06Z")
Hi I’ve been fully inspired by a post of thscrader (see https://forum.freecad.org/viewtopic.php?t=92659) and it has been a good opportunity to have fun with and test + dig into the PrePoMax interface for the first time. … --- ## [2 DoF Mass-Spring System - SPRING2 & SPRINGA Element Types](https://prepomax.discourse.group/t/2-dof-mass-spring-system-spring2-springa-element-types/2308)
**Author:** [@mhayrettin](https://prepomax.discourse.group/u/mhayrettin)\ **Replies:** 3\ **Last updated:** [December 28, 2024, 3:29am UTC](https://prepomax.discourse.group/t/2-dof-mass-spring-system-spring2-springa-element-types/2308 "2024-12-28T03:29:01Z")
Hi, In the version I’m currently using (v2.1.11) SPRING2 and SPRINGA elements can not be added in the UI. And these are needed to connect two or more bodies/nodes/remote points not to the ground but to one another. @FEAn… --- ## [Simple Shell Thickness Optimization](https://prepomax.discourse.group/t/simple-shell-thickness-optimization/2303)
**Author:** [@mhayrettin](https://prepomax.discourse.group/u/mhayrettin)\ **Replies:** 0\ **Last updated:** [December 22, 2024, 10:16pm UTC](https://prepomax.discourse.group/t/simple-shell-thickness-optimization/2303 "2024-12-22T22:16:50Z")
Hi, I’ve been trying to be more familiar with open source fea. This time, i built a simple shell model and tried to optimize thickness of shell elements. If you want to try something new on top of that, try yourself or … --- ## [Stresses at the integration points in ParaView](https://prepomax.discourse.group/t/stresses-at-the-integration-points-in-paraview/797)
**Author:** [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Replies:** 19\ **Last updated:** [December 20, 2024, 3:04pm UTC](https://prepomax.discourse.group/t/stresses-at-the-integration-points-in-paraview/797 "2024-12-20T15:04:49Z")
One of the limitations of CalculiX is that it can only output averaged nodal stresses in .frd files. If you need them at the integration points (where they are originally calculated and most accurate) you can use .dat fi… --- ## [automatedMultiRun.py : Automated analysis runs for multiple .inp files](https://prepomax.discourse.group/t/automatedmultirun-py-automated-analysis-runs-for-multiple-inp-files/2273)
**Author:** [@mhayrettin](https://prepomax.discourse.group/u/mhayrettin)\ **Replies:** 0\ **Last updated:** [December 18, 2024, 11:13am UTC](https://prepomax.discourse.group/t/automatedmultirun-py-automated-analysis-runs-for-multiple-inp-files/2273 "2024-12-18T11:13:23Z")
Hi, If you need to run multiple analysis sequentially you can use this script. GitHub Link automatedMultiRun.py : Automated analysis runs for multiple .inp files. What this code does? This script helps you to run mult… --- ## [How to perform a CPU benchmark for solver speed](https://prepomax.discourse.group/t/how-to-perform-a-cpu-benchmark-for-solver-speed/842)
**Author:** [@lucas\_bueno](https://prepomax.discourse.group/u/lucas_bueno)\ **Replies:** 5\ **Last updated:** [December 2, 2024, 6:33pm UTC](https://prepomax.discourse.group/t/how-to-perform-a-cpu-benchmark-for-solver-speed/842 "2024-12-02T18:33:44Z")
It’s been a while since I wanted to perform a benchmark of solver speed for my computer. After postponing it for too long, @FEAnalyst showed an excellent tutorial on this Polish site, and now I want to bring it (in Engli… --- ## [Understanding multistep analyses](https://prepomax.discourse.group/t/understanding-multistep-analyses/1526)
**Author:** [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Replies:** 2\ **Last updated:** [November 23, 2024, 10:22pm UTC](https://prepomax.discourse.group/t/understanding-multistep-analyses/1526 "2024-11-23T22:22:33Z")
Recently, there has been quite a lot of confusion around multistep analyses so let’s try to summarize the important rules (based on Abaqus but it should be the same in CalculiX), assuming that we are talking only about n… --- ## [Sharing materials database from FEA in production: automotive, defence, etc](https://prepomax.discourse.group/t/sharing-materials-database-from-fea-in-production-automotive-defence-etc/2196)
**Author:** [@Sound\_Spinning](https://prepomax.discourse.group/u/Sound_Spinning)\ **Replies:** 3\ **Last updated:** [November 19, 2024, 2:54pm UTC](https://prepomax.discourse.group/t/sharing-materials-database-from-fea-in-production-automotive-defence-etc/2196 "2024-11-19T14:54:47Z")
Hi There, I’ve noticed that PrePoMax has the ability to import ‘chunks’ of data via \*.inp files. Wonderful, Aba/CAE didn’t used to allow that, dunno now. So, I’ve compiled (part of) my structural materials from Abaqus … --- ## [Debugging convergence issues. Crime Scene](https://prepomax.discourse.group/t/debugging-convergence-issues-crime-scene/1880)
**Author:** [@ANYS](https://prepomax.discourse.group/u/ANYS)\ **Replies:** 4\ **Last updated:** [August 15, 2024, 2:50pm UTC](https://prepomax.discourse.group/t/debugging-convergence-issues-crime-scene/1880 "2024-08-15T14:50:24Z")
Hi Matej, I’ would strongly suggest that Last Iteration in the Field output is set up as “Yes” by default. Not sure if many users know about that option . In my experience , most of the convergence issues in nonlinear… --- ## [Using standalone CalculiX](https://prepomax.discourse.group/t/using-standalone-calculix/846)
**Author:** [@FEAnalyst](https://prepomax.discourse.group/u/FEAnalyst)\ **Replies:** 2\ **Last updated:** [February 8, 2024, 5:40pm UTC](https://prepomax.discourse.group/t/using-standalone-calculix/846 "2024-02-08T17:40:45Z")
Some PrePoMax users may not be used to running analyses outside of this GUI. And it’s sometimes necessary, for example in those cases: changes that can’t be handled by the keyword editor (like unsupported element types… --- ## [Number of processors makes a big difference!](https://prepomax.discourse.group/t/number-of-processors-makes-a-big-difference/1095)
**Author:** [@imgprojts](https://prepomax.discourse.group/u/imgprojts)\ **Replies:** 3\ **Last updated:** [June 9, 2024, 10:27am UTC](https://prepomax.discourse.group/t/number-of-processors-makes-a-big-difference/1095 "2024-06-09T10:27:49Z")
I was solving something this morning and had previously done a benchmark that I found here in the forum not long ago. The benchmark indicated that my computer’s ideal number of cores was 16. I’ve been using that number f… [Next page](https://prepomax.discourse.group/c/tips-tricks/11.md?page=1)