Additive manufacturing has different rules than machining or injection molding. Design for those rules and parts come out clean, fast, and cheap. Ignore them and you pay for it in failed prints and rework. Five rules worth knowing:

1. Mind the 45-degree rule. Overhangs beyond about 45 degrees need supports, which add time, cost, and post-processing. If a feature does not need to be there, remove it, or orient the part so it self-supports.

2. Design for the layer direction. FDM parts are weaker across layer lines than along them. If a part carries a real load, think about which axis the force follows and orient accordingly. Resin is more isotropic, but orientation still matters for detail.

3. Fillets beat sharp corners. Sharp internal corners concentrate stress and print poorly. A small radius costs nothing in CAD and buys real strength.

4. Hole sizing is real. FDM holes come out slightly undersized; resin slightly oversized. If you need a press fit or a bearing seat, design the hole for the process, or plan to ream it after printing.

5. Consolidate parts. If you can print it as one piece instead of five bolted together, you remove tolerance stacking, assembly time, and failure points. That is the single biggest win additive gives you over conventional manufacturing.

None of this is exotic. It is the difference between working with the process and fighting it. We bake these rules into every design we deliver, which is why our parts fit the first time.