How to manufacture a prototype of your enclosure for an electronic device
By: Ivan Kuten
Tags: Prototyping, Electronics Manufacturing, Electronics Engineering, Product Design, Industrial Design

How to manufacture a prototype of your enclosure for an electronic device

If you want to make a live sample of your 3D design or sketch, you will have to deal with prototyping, 3D printing, or milling. Ivan Kuten Follow Nov 27, 2020 · 5 min read

Fishfinders with waterproof plastic enclosures and rubber-like coating. Photo by Promwad Manufacturing

A case or enclosure prototype for your new hardware product gives a clear understanding of technical feasibility of your idea. A manufactured sample is always more visual and convincing than a drawing or 3D model. It is advisable to bring it as close as possible to a serial or mass manufactured sample (so called DFM approach or design for manufacturing).

When creating an enclosure prototype, you will need to choose its manufacturing technology, prepare documentation, calculate costs, and plan delivery routes. Also, a prototype will allow you to check hardware and software, evaluate the ease of use, conduct climate tests, select the material and components for assembly, and finalize the device’s design documentation.

Each project is unique. However, several universal solutions are suitable for most cases. The common prototyping technologies are 3D printing and CNC milling.

Rapid prototyping or layer-by-layer extension on a 3D printer

SLA technology: Stereolithography Apparatus

How it works: the UV laser interacts with light-sensitive resin to make the SLA model. This technology is fast and highly accurate, ideal for complex and bulky parts. SLA surface is easy to process. The downside is that only one material is used, and the products are too fragile for screws and latches.

SLS technology: Selective Laser Sintering

The laser beam bakes the powdered component to make the SLS model. Typical materials for prototyping: metal, plastic, and ceramics. This technology is notable for its accuracy and durability, but surface finishing is relatively tricky.

FDM technology: Fused Deposition Modeling

The DFM method allows you to obtain a product close to a factory sample. An enclosure is formed by jetting a molten polymer thread on a moving platform. Overlapping each other, the layers harden and create a relatively rough surface, which can cause difficulties in the final processing.

It would help if you did not rely on a prototype as a one hundred percent reflection of your future device — its appearance without processing and surface finishing will be far from ideal. The main task of these methods is to check your idea quickly and at a relatively low cost. Then the degree of price-quality balance is determined: you can, of course, make a more expensive prototype with final processing. Such prototypes can be used for demonstration at exhibitions, meetings with investors, and for certification.

Selection of materials for electronic product enclosures are based on various factors: the purpose of your device, customer choice, price range, and design decisions. This is one of the many tasks for industrial and mechanical designers. They can use multiple types of plastic, metal, wood, glass, rubber.

Devices manufactured by Promwad with the use of quartz glass & aluminum, ceramics & wood, respectively

Types of available plastics for enclosures:

ABS — thermoplastic impact-resistant resin, easy to process, oil products are the basis. Also, some types of ABS are not recommended for use in systems exposed to direct sunlight.

PLA — thermoplastic biodegradable raw materials, durable and transparent, smoothly coloured, has a plant origin. Minuses: harder than ABS, it is more difficult to process and grind.

HIPS — durable and very ductile material, which is also essential, environmentally friendly. It can be primed, sanded, and painted.

PC — impact-resistant polycarbonate, resistant to chemical influences, easy to process.

PA — hard and resistant polyamide, machinable.

PP — polypropylene, one of the safest plastics.

POM — characterized by high durability and resistance to loads, low temperatures, well painted.

Types of metals that can be used for enclosures (including unusual): stainless steel, aluminium alloys, zinc, brass, copper, bronze.

3D milling on machines equipped with computer numerical control (CNC)

Let’s look at the second major prototyping technology allowing you to produce a large number of parts of any complexity and size (from a couple of millimeters to several meters).

With CNC milling, you will be able to choose from a variety of materials: acrylic, teflon, MDF, polyamide, and other plastics.