Designing for Additive Manufacturing – DFAM

Designing has always been around for as long as there has been innovation around. We have used basic sketches to create ideas for products, for mechanisms, overall to create solutions for our own problems of the world. Everything that you see physically in your day to day life has been through at least one round of design iteration. Why? Because innovators are always looking to go that extra mile to make their product look and function as they desire and more.

Designing has many types. Say, for a simple shirt, a 2D design sketch of the TOP VIEW is enough. Well many of the houses that have been built have sufficed with 2D drawings itself. And for decades, engineers and manufacturers have used 2D drawings to create innovations in what we now call the “industrial age”. 3D designing is another step from the already proven 2D drawings. 3D gives the accuracy and that added view to boost your confidence in your own design (not that it is needed but it is good to have). 3D Designs help machines understand how to fabricate with high precision and also increase your throughput and reduce your rejection rate.

3D Designing is only required if you want to have a machine do your fabrication work and not a human. Because machines do not read 2D drawings, humans do. Say, you are fabricating a simple L Bracket, the human operator understands your requirement and reads the 2D drawings to make it as per your requirement and if that L bracket were to fit snugly into an already existing part you must have drafted your tolerances right or you must give the other part to the human operator to fabricate it manually. But, if you want to use a machine to fabricate, it only understands 3D Design that you provide as input and depending on how accurate the machine fabricates and the tolerances you have given, you will have to go through 1 or many fabrications until you have the right fit.

As you can see, 3D designing is CRITICAL for new age manufacturing. And so we have a simple guideline we follow to ensure the minimum number of iterations to achieve the right fit.

All you need to do is answer four simple questions to understand the suitable technology for fabrication or as we call it “DFAM QUESTIONS”

  1. Is it for end use or for prototyping?
  2. If it is for end use, what environment will it be in?
  3. Is it a core, functional part of the mechanism or is it an enclosure?
  4. How big is the part?

Answering these questions, in turn tells us our DFAM values, what are the DFAM values you ask?

They are – two main design values or as we call it “DFAM Values” to keep in mind while designing for any fabrication processes, they are:

  1. Minimum wall thickness
  2. Tolerance

There will be many more things to keep in mind but these primarily dictate how your end product will turn out to be.

Here is a case study of SWAMY TECH Engineers doing a manual reverse engineering of a printer panel from scratch.

First we need to answer the DFAM questions

  1. Is it for end use or for prototyping
    – End Use
  2. If it is for end use, what environment will the part be in ?
    – Room temperature use as a flap to refill papers
  3. Is it a core, functional part of the mechanism or is it an enclosure?
    – Not the core part, but a good to have part
  4. How big is the part?
    – 18in * 5in * 5in

This helped us decide to go for FDM or FFF 3D Printing. Answering these questions, in turn tells us our DFAM values,

  1. Minimum wall thickness – 2mm
  2. Tolerance – 0.3 to 0.4mm

Since this was manual reverse engineering we need to have good tools.

  1. Vernier scale
  2. Angle measuring scale
  3. Metal scale
  4. Transparent scale
  5. Patience (Lots of it)

Design Upgrades | Software used : FUSION 360

It took us 3 days and we had the final design ready and once the necessary design upgrades were done as per the client’s request, we proceeded for 3D printing with our in-house 400*400*400 3D printer, we used white PLA as it was best suited for the application and overnight the print was ready.

In 5 days from requirement to delivery – That is the speed of technology, the right tools and knowledge.

Thank You

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