A common and costly mistake is to treat the manufacturing process as an afterthought, drawing one generic model and simply hoping it suits whatever machine it eventually lands on. In reality, printing and machining pull a design in genuinely different directions, and the model really should be built for the route it will actually take rather than left to chance. A wall that is perfect for a milled aluminium bracket can be far too thin for a printed one, and a sharp internal corner that costs nothing on a printer adds real time on a mill.
Our CAD team designs with the process in mind from the very start, and adapts a model carefully whenever a part switches from one route to another. The same idea can become two quite different files, each tuned to make the part well, and knowing how they differ helps you understand why that effort is worth it rather than an unnecessary duplication of work.
Designing for printing
Printing builds material up in layers, which makes some shapes effortless and others awkward. Overhangs steeper than roughly 45 degrees from vertical usually need support, large flat areas can warp as they cool, and hollow shapes are not only allowed but actively encouraged because they save material and printing time. The whole logic is one of adding only what is needed.
A printed part can also carry complex internal geometry, lattices and flowing organic curves at little or no extra cost, so the model can be genuinely ambitious in ways a machined part never could. The trade off is paying close attention to wall thickness, print orientation and where supports will land, since those decisions shape both the surface quality on critical faces and the final cost of the part.
Designing for machining
Machining cuts material away with a rotating tool, so all the rules effectively flip around. Internal corners can never be perfectly sharp because the tool itself is round, deep narrow pockets are hard or impossible to reach, and undercuts may demand special setups or simply cannot be made at all on a standard three axis machine.
A machined part therefore wants generous internal radii, accessible features and as few separate setups as possible, because every time the part has to be unclamped and refixtured it adds real cost. The model should reflect those realities honestly, since a shape that ignores them can quietly turn an affordable part into an expensive one without you ever realising why.
Where the cost really lives
The price of a part is rarely driven by its headline size or even the material, but by the small features that quietly make a process work harder. On a printer the main cost levers are the volume of material, the print time and the amount of support that has to be removed by hand afterwards. On a mill or lathe the cost is driven by the number of setups, the depth and tightness of any pockets, and how much material has to be cut away to reveal the final shape.
Understanding which lever you are pulling lets you design a cheaper part without losing anything that matters to how it works. Rounding an internal corner to suit the cutter, opening a pocket so a shorter and stiffer tool can reach the bottom, or hollowing a printed body to cut its mass are all small changes that barely alter the function yet noticeably lower the bill. We make those calls as we model and explain the trade offs so you can decide where the money is best spent.
One idea, two models
When a part might be printed for prototypes and then machined for production, we often build two versions from the same underlying intent, each carefully tuned to its own process. That keeps the prototype cheap and quick while making sure the production part is genuinely ready for the machine shop rather than needing a redesign at the last minute.
- Add internal lattices and hollows for printed versions.
- Open up internal radii for machined versions.
- Adjust clearances to suit each process accuracy.
- Reorient features to reduce supports or machine setups.