Design for Manufacturing Starts on Day One
There always needs to be a balance between speed to prototype and taking the time to design parts with their manufacturing intent built in. Here’s how I approach DFM, and I hope that it can help others who may just be starting out.
I like to use the phrase “Do it nice, not twice.” It might sound silly, but it works.
Not doing DFM from the start can come back to bite you, big time. Everything from part fitment to part function is reliant on how that actual part gets manufactured. You cannot beat physics. Are you designing a part that experiences a certain load during operation? Your method of manufacturing, material options, and manufacturing limitations are all at play. Are you designing a part that physically moves during operation? CNC’ing it versus casting is going to have a massive impact. Yes, it is great to learn fast, but in my experience small modifications to parts (especially ones that move and interact with other parts) can cause big surprises unless you design them out of the gate with the features they need to be made in the real world at scale.
Sometimes engineers and designers skip this step because they think it will save them time. You may get to a prototype faster than if you skipped the steps necessary to do DFM, but what happens when the prototype works, and then the manufacturable version doesn’t?
Your pre-tool MVP has to be prototyped with basic DFM’d features. Molding strategy, drafts, wall thicknesses, split lines, accommodations for lifters, etc. I have seen too many companies (especially startups moving fast) get burned when they design a prototype not understanding this, and then throw it over the wall to a CM for manufacturing. Sometimes parts can’t be made at all, and it requires time for a redesign. Every time you redesign something, there is always an opportunity that a new issue can be lurking. Now you need an entire extra prototyping cycle, because going into EVT without any verification and validation is incredibly risky.
DFM gets easier if you design cleanly. There are so many wonderful CAD tools out there these days that make modeling easy. Model clean. Keep structure, and build your tree so that any modifications to the parts and assemblies you design carry through without blowing anything up. I know the Move Face tool is fast, but paying now is often better than paying later.
As you gain more experience, this method may add an extra couple of hours to the front end, but it can save you months and an immeasurable amount of money on the back end.
Do it nice, not twice.