3D printing for prototypes and small parts

3D printing is the right call when you need one piece or a few dozen, fast, without a mold: a prototype enclosure, a bracket, a replacement part you can't buy anymore, a model for a presentation. Two choices matter most: the technology (filament or resin) and the material, based on what the part has to withstand.

When it makes sense and when it doesn't

3D printing wins on small runs and on parts that are still changing. You edit the file, print again the next day, compare. You don't pay for a mold for a shape that might look different next week.

It loses on large runs of identical parts, where a mold and injection molding pay for themselves, and on parts that must look factory-finished with no post-processing. The fine layer lines on filament prints are visible, even if only up close.

Good examples for a business: a test enclosure for an electronic device before the final run; brackets and spacers for a trade show booth; a broken clip from a machine, rebuilt from measurements; a product model for photos.

Filament or resin

These are the two technologies you'll run into most often:

For functional prototypes and parts that get mounted somewhere, filament is the usual choice. Go with resin when fine detail matters more than impact resistance.

Which material to choose

With filament, three materials cover most parts. The figures below come from Prusa, a maker of 3D printers and filaments:

• PLA is the easiest to print and works well for models, form prototypes and objects that don't see wear. It softens and deforms above 60 °C, degrades under UV light and isn't recommended for technical or outdoor parts.
• PETG is tough and a little flexible, so it doesn't snap easily. It's commonly used for mechanical parts, holders, clamps and waterproof parts, including outdoors, below 80 °C.
• ASA resists UV and temperatures up to 93 °C, so it suits outdoor use. It warps more during printing and needs an enclosed printer for large parts.

A simple example: a phone mount for a car dashboard printed in PLA can bend out of shape on an August afternoon. In PETG or ASA, it holds up.

Detail, time and strength

Layer height is the main setting for print time and vertical detail. Thicker layers print faster but show more visible lines. Thinner layers mean more detail and more time. Prusa advises against going below 0.10 mm, because past that point the quality gain is small and the print time climbs fast.

Two things few people know:

• layer height only affects detail in the vertical direction. Raised text lying flat on the print bed looks the same at any layer height; for finer horizontal detail you need a smaller nozzle;
• a part's strength depends mostly on the number of perimeters (walls), not on how solid the inside is. When a part has to carry weight, we add walls first.

What to send us so it comes out right

1. The file, ideally STEP or STL. If you don't have one, a sketch with dimensions or the old part, which we'll measure.
2. Where the part lives: in the sun, near a heat source, in water, outdoors.
3. What it does: just looks good, holds something, fits into another part.
4. What it fits with, including the dimensions of the mating part. For parts that fit together, we print a sample first and adjust from it.
5. How many pieces and by when.

Cost depends on part size, material, print time (which includes layer height) and finishing afterward. The price comes with the quote, once we've seen the file. See what we print on our 3D printing page, and for company orders, on our business page.