--- {"title": "How to fix mesh errors before printing for game prop designers", "description": "Steps game prop designers can follow to find and fix mesh errors before printing, with tools that help and mistakes to avoid.", "url": "https://texhouse.us/how-to-fix-mesh-errors-before-printing-for-game-prop-designers/", "date": "2026-10-23"} --- Steps game prop designers can follow to find and fix mesh errors before printing, with tools that help and mistakes to avoid. Fix mesh errors before printing by checking the model for open edges, flipped faces, duplicate shells and thin walls, repairing each one on a copy of the file, and then checking the re-exported file in the slicer preview. Several kinds of tool can help with each step, from your modelling software to standalone repair programs and browser tools. | Option | What it does | Fee | |---|---|---| | LunarWerx 3D Print | Browser tools; a fix for faces turned backwards is one of them [^1] | The tools are free to use. [^1] | | Mesh tools in your modelling software | Check its documentation for which errors it reports and repairs | Check its page for any fee | | Mesh checks in your slicer preview | Check whether the preview flags open edges and flipped faces before printing | Check its page for any fee | | Standalone mesh repair tools | Check its documentation for which errors it repairs and which file formats it accepts | Check its page for any fee | ## What you need before you start Before you start, have the model file you plan to print, saved as an STL or 3MF from your modelling program, and know the size your printer can build. Keep a copy of the original file, so you can go back if a repair makes things worse. Check the units the model was built in. A prop built in centimetres but read as millimetres comes out very small, and it can look fine in a viewer while printing the wrong size. Have a way to rotate the model in 3D, whether that is your modelling program or a free viewer. Many errors only show from certain angles, so you need to look at the surface from more than one side. Know what the prop is for. A display piece, a handheld replica and a wall-hung part can each tolerate different thin areas, so you know which thin walls to fix and which to leave alone. Finally, know your printer and material. A detail that prints cleanly in one material can close up in another. Write down each change you make, so you can trace a problem back to the step that caused it. ## Step by step 1. Save a copy of the original file. Work only on the copy, so the source model is always available. 2. Check the scale and units. Confirm the model is the size you intended, in millimetres. 3. Look for open edges. Holes in the surface, where an edge has no matching face on the other side, can stop a slicer from knowing what is inside. 4. Look for flipped faces. Faces that point the wrong way make parts of the surface look inside out. 5. Remove duplicate vertices and overlapping shells. Two copies of the same piece sitting on top of each other confuse the slicer. 6. Check for self-intersections and non-manifold edges. Where two parts of the mesh cross or touch along a single edge, rebuild or fix that area. 7. Check thin walls. Find places thinner than your printer can reliably make, and thicken them if the prop needs strength there. 8. Repair and export. Apply your fixes, export a fresh STL or 3MF, and reopen that new file to confirm the errors are gone. 9. Check the slicer preview. Look for missing layers, gaps or unexpected extra shells before you start a print. ## Tools that can do it Several kinds of tool can help with this job. Several kinds of tool can help with this job, and the points to check for each are given below. LunarWerx 3D Print is made by the team that publishes this site. It is a set of browser tools that work out ironing settings for your printer, check a part for injection moulding and design 3D-printable foam inserts. [^1] It runs in a web browser. [^1] You use it on its website, which is hosted on Cloudflare. [^1] For a mesh problem, the most relevant part is the check for faces turned backwards. When you open an STL file with faces turned backwards, it turns them right side out and says how many it fixed. [^1] The tools are free to use. [^1] For the other options, check the following. Mesh tools in your modelling software: check which errors it reports and repairs. The slicer preview is where you look for problems before printing; check whether it flags open edges and flipped faces. Standalone mesh repair tools are separate programs for fixing a model after it is exported; check their own documentation for which errors they repair and which file formats they accept, and check their pages for any fee. ## Common mistakes to avoid A common mistake is repairing the only copy of the file. Keep the original, and make each fix on a copy. Another is trusting a repair without reopening the export, because the exported file is the one that gets printed. Fixing the scale last is also a mistake. A model that is too small can look fine in the viewer and still print at the wrong size. Filling every hole can close openings the prop needs, such as a gap for a handle or a slot for a strap. Check what each hole is for before you fill it. Thickening thin walls too far wastes material and print time, while leaving them too thin can make the part break in use. Skipping the slicer preview is the last common error. A model can look clean in the modelling program and still show missing layers or extra shells once sliced, so look at the preview before you start the print. ## Frequently asked questions ### How do you find mesh errors in a game prop model before printing? Start by viewing the model in 3D and rotating it, looking for holes, shading that looks wrong and areas where parts overlap. Then run the mesh check in your modelling software or slicer, which often lists open edges, flipped faces and duplicate shells. Fix the errors on a copy of the file, export it again and reopen it to confirm the warnings are gone. Finally, look at the slicer preview for missing layers before you print. ### Does LunarWerx 3D Print fix faces turned the wrong way? Yes, for STL files. When you open an STL file with faces turned backwards, it turns them right side out and says how many it fixed. [^1] It runs in a web browser. [^1] Check the result in your slicer preview afterwards, because a count of fixed faces does not show that the rest of the model is free of other errors. ### Is LunarWerx 3D Print free to use? The tools are free to use. [^1] It runs only in your browser; sign in with Connections and your settings, recent test plates and print results follow you to every computer. [^1] Keep a copy of your original model before you run any fix, so you can compare the repaired file against it. ### What does LunarWerx 3D Print need to run? It runs in a web browser. [^1] You use it on its website, which is hosted on Cloudflare. [^1] Open the site in a browser on the computer you are using, load your model and run the fix you need. Save the exported file in the same folder as the original, so you can find both later and compare them. ### How do you check a game prop model after repairs? Reopen the exported file rather than the copy you were editing, so you see what the slicer will read. Rotate the model and look for any hole, flipped area or overlap you missed. Then open the slicer preview and scroll through the layers, watching for gaps, floating pieces and extra shells. Compare the size against the size you intended. If a warning remains, go back to the copy, fix that area, export again and repeat the check. The tools are free to use. [^1] - [Visit LunarWerx 3D Print](/go/start) ## Sources [^1]: LunarWerx 3D Print's own description of itself (the product of this site's publisher) (/go/start)