Why electronics and 3D printing work well together
Electronics change fast. A new board revision moves a connector, an extra sensor needs an opening, a battery gets bigger. With injection moulding, every change means modifying the mould. With 3D printing, you edit the file and reorder.
That's why 3D printed enclosures show up mostly in prototypes, pilot runs, measuring equipment, test rigs and products sold in tens or hundreds. Injection moulding only becomes attractive at large, stable volumes.
Below are four typical applications. Each worked example is the part's volume times the material's starting price, excl. VAT and finishing.
1. Enclosure in a small run
The question: your device works and you want to sell or roll out a few dozen to a few hundred. The enclosure has to look finished, survive a knock and take screws.
The approach: MJF in black PA12. The black material gives an even matte look without painting. PA12 is tough, so clips and screw bosses don't snap off at the first try, and MJF delivers the same dimensions from part to part. For a smoother look, the enclosure can be bead-blasted or painted afterwards.
Worked example: 55 cm³ × €0.70/cm³ = from €38.50 per part, excl. VAT. That covers top and bottom shell together. Your actual price is shown in Quotebase; volume × material price is just a starting point.
2. Light pipe or display window
The question: the status LED sits on the board, but its light has to be visible on the outside. Or you need a small window for a display.
The approach: SLA in Clear Resin, printed in house. SLA gives fine detail and a smooth surface, which you need to let light through. It only becomes truly clear after sanding and polishing or a clear coat; without finishing the part is translucent rather than transparent. Keep the light pipe short and straight for the best result.
Worked example: 4 cm³ × €0.50/cm³ = from €2.00 per part, excl. VAT. Polishing or coating is extra. Your actual price is shown in Quotebase; volume × material price is just a starting point.
3. Flexible buttons and seals
The question: you want a button pad that sits over the board's tactile switches, or a flexible edge that keeps dust out of the enclosure.
The approach: SLS in TPU. TPU is a rubber-like plastic that compresses and springs back. SLS also handles thin living hinges and small details without supports. How well a seal actually seals depends on the design, the clamping force and the application; for a guaranteed protection rating you test the finished product.
Worked example: 3 cm³ × €0.85/cm³ = from €2.55 per part, excl. VAT. Small parts like this are usually ordered together with the enclosure. Your actual price is shown in Quotebase; volume × material price is just a starting point.
4. Test rig or look-alike model
The question: you want to check that the board, connectors and cables fit before you order a run. Or you need a model for a trade fair, a customer meeting or a photo.
The approach: SLA in Grey Resin, printed in house. Grey resin shows details and edges clearly, which helps when judging fits and looks good in a photo. Standard resin is less tough than PA12, though: use this model to check and show, not to snap clips open and shut repeatedly.
Worked example: 70 cm³ × €0.45/cm³ = from €31.50 per part, excl. VAT. Your actual price is shown in Quotebase; volume × material price is just a starting point.
Overview of the worked examples
| Application | Technology and material | Volume | From, per part, excl. VAT |
|---|---|---|---|
| Enclosure, small run | MJF, PA12 black | 55 cm³ | €38.50 |
| Light pipe or window | SLA, Clear Resin | 4 cm³ | €2.00 |
| Button pad or seal | SLS, TPU | 3 cm³ | €2.55 |
| Test rig or look-alike model | SLA, Grey Resin | 70 cm³ | €31.50 |
All amounts are starting prices per part, excl. VAT and finishing such as polishing, painting or fitting inserts.
Design tips for a 3D printed enclosure
Snap-fits
- Make snap-fits in PA12 (MJF or SLS). It flexes; standard SLA resin is too brittle for clips that get opened and closed often.
- Give the clip a long arm and a rounded root. A sharp corner at the root is where it will break.
- Allow clearance between the two shells. Printed parts have a small dimensional tolerance; without clearance the enclosure won't close or will creak.
Screw bosses and inserts
- If the enclosure is rarely opened, self-tapping screws for plastics in a properly sized boss are enough.
- If it's opened often, use brass heat-set inserts in the PA12. Size the hole to the insert manufacturer's specification.
- Brace screw bosses with ribs to the wall. A thin, free-standing boss snaps off easily.
Ventilation and heat
- Put ventilation slots at the bottom and the top, so warm air can rise and fresh air comes in from below.
- Plastic conducts heat poorly. Let a hot component shed heat to a metal heat sink or through an opening, not into the enclosure.
- A printed plastic enclosure doesn't shield against electromagnetic interference. If you need that, discuss a conductive coating or metal shielding up front.
General
- Keep walls evenly thick and avoid large solid sections. That limits warping and keeps the volume, and so the price, down.
- Draw connector openings slightly larger than the connector and check them on a look-alike model first.
- Text and logos read best as raised or recessed lettering at least a few tenths of a millimetre deep.
Choose the technology by function
- Choose MJF in PA12 for enclosures that see real use, with clips, screws and an even look.
- Choose SLA for clear parts, fine detail and look-alike models.
- Choose SLS in TPU for anything that has to compress or spring back.
- Only move to injection moulding once the design is fixed and volumes are high enough to pay back a mould.
Makernaut does SLA and finishing in house. MJF and SLS run through selected partners. For injection moulding, request a quote in Quotebase and you'll get an answer within one working day.