Guide
3D printing or CNC? How to choose for your part
Four questions that decide it in most cases, and why the answer is sometimes both.
We make the same bracket both ways every month, for customers who want to compare. The printed one is lighter and cheaper in small numbers; the machined one is stronger and more precise. Which is right depends on four questions.
1. How many do you need?
Printing has almost no set-up cost, so one part costs about the same as the tenth. Machining needs programming and fixturing first, which pays off from a few dozen parts upwards.
2. How precise must it be?
Printed nylon holds about ±0.2 mm. Machined aluminium holds ±0.01 mm as standard. If only a few features are critical, print the part and machine those features afterwards.
3. What shape is it?
Internal channels, lattices and organic shapes are easy to print and hard or impossible to machine. Flat faces, sharp edges and threads favour machining.
4. What must it withstand?
For heat, heavy loads and wear, machined metal still wins. For light brackets, housings and ducts, printed nylon is usually more than strong enough.
Not sure? Send us the model. We quote both when it is close, and tell you which we would choose.
