Most functional prints don't fail because the STL is "bad." They fail because people slice display models and then bolt them to something.

I print brackets, jigs, and replacement clips on Bambu and Ender. Same file. Different machine. These three settings decide if it holds.

1. Walls, not infill

4 walls. 40% gyroid is enough. Going to 80% infill on a clip doesn't make it stronger. It makes it warp. Strength on FDM is the perimeter.

2. First layers are the joint

Bambu will hide a dirty bed. Ender will not.

If layer 1 looks like spaghetti, stop. Wash the plate. Don't add glue on top of dust.

3. Don't print the hole undersized and "drill it later"

For screw bosses, add 0.2 mm clearance in the slicer. Drilling PLA after the fact ovalizes the hole and the screw walks.

If a part still fails after that, it's usually a nozzle or a bent gantry — not the file. That's a live session, not another STL.