3D printing for IoT prototypes -Best Practices and Thumb rules

I am honored and privileged to have this article co-authored by Vivek , a passionate and extremely talented Industrial engineer and product designer at Techolution. I have collaborated with him during my stint at Techolution for various key initiatives. Through this article, we would like to cover how we leverage 3D printing for various IoT prototype activities. What are some best practices, pit falls, limitations, etc.

Application Areas

Below are the following use cases or requirements for which we have leveraged 3D printing for IoT

  • Custom components for our proprietary hardware products
  • Purpose built accessories for our hardware products
  • Micro manufacturing of smart sensors

Why (in-house) 3D Printing

The application areas that we have mentioned above are nothing new and possibly many have used for the same purpose. However, below are a few reasons why we have adopted 3D printing to achieve the same and too with an in-house 3D printing setup.

  • Enclosures should be of correct size and serve the purpose well. Generally off the shelf enclosures follow standard dimensions. At a prototype level, we should have an enclosure which just has the correct dimensions and appropriate provisions. At Techolution we developed an edge device for Industries. It has numerous interfaces and outputs. Since the demo kit will be used by sales folks, we need to have it correctly sized so that it can be carried easily, has appropriate vents for air circulation and heat management, enables us to position components (both input and output) and sensors in a most optimum way, hide the interfaces which are generally used by support team(E.g USB ports etc) from users , but can be accessed by support team when needed, provide holes of appropriate dimensions (sub 10mm diameter) for antenna etc. In such requirements, using an off the shelf enclosure might end up spoiling the aesthetics and visual appeal.
  • Components can be made for use cases which are way ahead of time or for unconventional use cases. Assume that you are hacking a robot vacuum cleaner for a function which it is not intended to perform. You need a few extra components to achieve its purpose. As you innovate, and do different trials and improve it, 3D printing helps you significantly.
  • Purpose built accessories: Though if you are buying an existing component in the market, if a specific accessory needs to serve a different purpose as well, how would you achieve it?3D printing definitely helps here.

Decisions to take before printing

In many ways, 3D printing is similar to constructing a house. There are a lot of questions to ask and decisions to make before going to the design itself.

  • Where it is being used: Is the printed object going to be used or be placed(either in transit or usage) in extreme conditions? How it will be positioned. For e.g in our industrial edge use cases, sensing elements should be exposed to the sensing object. In case if the device is to be fitted on the ceiling, it does not make sense for the sensing element to be facing the ceiling. So the engineering team of the product should brief the designers about the end use and goal of the object being printed, where it will be used, how it will be used etc. Are the components being printed withstand the deployment conditions. For e.g, if you are printing a device which will be used in a steel plant, it should be able to withstand high temperatures etc.
  • Scope for future enhancement: Should you need to design the object considering future goals.
  • Hide and Seek : As mentioned earlier, in some cases you might need to expose only a minimum things (E.g only power input etc), but few other ports (e.g USB, HDMI) to be available for troubleshooting, So designer should design it so that installation team or engineering team can access them without removing the entire casing or enclosure etc.

Our Setup

Manufacturer : Raise3D

image credits: www.raise3d.com
lab machine at Techolution
image credits: www.raise3d.com
Lab Machine at Techolution

Large Build Volume

A build volume of 305mm x 305mm x 605mm gives the user the flexibility to print long & large prints for their prototyping.

image credits : www.raise3d.com

Supports Variety of Different Materials

The printer supports a variety of plastics & composites which gives the user the flexibility of exploring into the domain of material science.

image credits : www.raise3d.com

Intuitive User Experience

Visual interface / Rapid reviewing / Visual print progress / Full adjustment control.

image credits : www.raise3d.com

Power Loss Resuming

The printer in the scenario of a power shutdown, it stored the print status in its memory & we can resume the task once the power is back.

High Performance Motion Controller

400 MHz ARM Cortex- M7 32 bit RISC FPU and a 256 micro-steps driver system

image credits : www.raise3d.com

User Interface : Remote administration capabilities

The printer comes with a Raise3D cloud solution, where-in the controlling, monitoring & the complete additive manufacturing project management can be executed by the user through an electronic device with an OS [ Windows, Linux & iOS ]. It also provides a browser based interface

image credits : www.raise3d.com

Time to Print

These are three factors which affect the time required to print a 3D component. They are

  • Size of the components
  • Part placement orientation
  • In-fill density
  • Support structures generation
  • Print speed settings
  • Cost of material usage
  • Virtual simulation of the complete 3D-printing process
  • Time taken for the printc

Key Learnings

  • Since time taken for 3D printing is influenced by a lot of factors, plan ahead accordingly. Once you run a sample run, you can guess some reasonable time for the machines you are using. There are a lot of open source models for you to print.
  • 3D printing is not suited for mass manufacturing. It may at best serve orders for small quantities. Have a road map from prototyping to mass manufacturing
  • If your printer cannot support multiple materials and if having multiple materials is mandatory for the prototype, think of alternatives ahead of time.
  • The 3D printers cannot give high IP rated objects. So if you are using it for deployment in extreme conditions, work with your product engineering and design team to achieve it.
  • While choosing a 3D printer, choose a machine which helps you to monitor the job and its status remotely. This will help the team to be more productive.
  • Have more than one unit of 3D printer if you are using it heavily. We have experienced unplanned downtimes due to filament issues, filament jam etc. Having an extra machine helps to mitigate single point of failure
  • Have enough stock of accessories, tools for maintenance & back-up of parts like nozzles, heat sinks / hot end assembly like filaments etc handy
  • Spare parts / replaceable parts for a product deployed can be 3D-printed by the OEM or even at the end customer due to which the serviceability / maintenance can be carried out in a more efficient way.

Design rules for 3D printing

image credits | www.hubs.com

Factors affecting the quality

Layer Thickness

Let’s take a single layer into consideration. The crucial factor is the layer’s thickness. This determinant is not only connected to slicer settings (that you use to obtain your gcode) but also to the 3D printer you are using. The rule is simple — the smaller layer thickness, the better the quality of a 3D print. Although thin layers will make your print’s walls smoother, you have to bear in mind that it will take a 3D printer much more time to accomplish printing.

image credit | www.hubs.com

Material Quality

This factor may be obvious to some users, but I would like to dig deeper into the subject. Mechanical properties of a material are reflected in a 3D print’s features. There are no illusions — poor material properties will affect the quality of a 3D printed object, especially in a field of impact strength and hardness. Moreover, if a low-grade filament is contaminated, the risk of the extruder jamming is rising.

Printing temperature

This factor is strictly related to the slicer set up that is — most commonly — easily accessible by the user. The temperature of plastic extrusion must be configured differently for every type of material. On the other hand, Zortrax materials can be automatically recognized by the 3D printer — Zortrax M200 will apply the best 3D printing settings as soons as you hook a spool on a holder.

Retraction settings of the Extruder

This feature can be configured in your slicing software. Configuration of material retraction is very important when the extruder needs to travel some distances without actual extrusion. For example, when you are printing fishnet objects and the printhead jumps to perimeters.

Sparse- or Solid-Fill

If you have an enclosed part, like a cube for example, it can be filled solid or Stereolithography and Fused Deposition Modeling allow you to build with a custom interior density using air gaps between the exterior walls. This build technique, called ID-Light, uses less material and is faster, resulting in a lower price compared to a solid-fill, however it can slightly affect overall part strength. We recommend working with a project engineer on these applications.

IoT Solution Architect