By | Oct 14, 2022 | Categories: All


Today we continue talking about Product Development. Alex Gudilko, CEO of AJProTech, shares our mechanical experience and tips in a series of videos about product development: HOW TO CREATE AND LAUNCH NEW HARDWARE PRODUCTS.

We covered the electrical portion. Let’s go to mechanical. 

Mechanical designFor this one, I’m going to introduce another case study of ours which is the portable water generator, which has a lot of mechanical parts. This is going to showcase our mechanical job the best.

Mechanical design

When you start working on a prototype you need to think how each part is going to be manufactured. So before you start doing any design – divide your product  into pieces and think about how each of them is going to be manufactured.

There are multiple ways to prototype mechanical components. Today we will cover:

Mechanical prototyping

  • 3D printing, 

  • CNC Machining 

  • Silicone Mold.

3D prints are 

  • easiest to get 
  • no startup costs
  • cheap and fast
  • Lower mechanical properties

Quality is on average adequate to the cost. 

CNC machining is a better alternative

  • Higher quality and better look
  • Better mechanical properties
  • Requires special design considerations

When you carve the unit out of a solid piece of plastic, it requires some certain design consideration. For example, how far the mill can go into the plastic. 

Silicone Molding, let’s cover this one in detail

Silicone mold

  • Perfect look
  • Low startup expenses for mold
  • Validate before injection molding
  • 10-100 pcs max

This allows us to create really high quality prototypes without big investment for tooling. The way it works is that you make a master model either CNC machine or 3D printed. Polish it, really make it look nice and feel nice. Then you put it into a solid piece of silicone to create a cavity and then you pour the melted plastic inside that silicon. This way you can create either anywhere from 10 to 100 pieces with really high-quality and low-investment into a tooling. Usually the price for it is below $1000 for small parts. And those components look exactly as the injection molded units but you don’t pay thousands of dollars for the mold.


Once mechanical components are there, assemble modules. This is the time to log down on which components are going to be used eventually, so take your time to validate things here. There are no significant changes for components after the EVT phase.

Prototypes assembly

We recommend doing most of the assembly in house. Don’t involve the CM at this stage. Engineers who are working on a design need to be involved in the assembly. They learn a lot, they see how it can be improved. Really take time to take this expertise in house and see how things get together. 

Firmware and bringup

In parallel with mechanical and electrical design, there should be work on a firmware. Firmware development starts from the ground up from how the device powers up, how the core functions work and you go all the way up to API and connectivity layer. On average we recommend spending at least 30% of time on validation. If it takes you 3 months to develop firmware, allocate at least 1 month for complete testing. Test everything because engineers like to rush into production. Take some time here and really validate things.

Final prototypes

In the end, it's a really rewarding process. You get Final EVT Prototypes that look like final products, they work like final products. They might have some cosmetic defects, they might have some finish differences or color differences but they look really good and you can raise money with those.

Final work like prototype

Another example of EVT prototype for the headphones product. Sometimes it is acceptable to use non final materials if it costs too much to use proper plastic, for example, here we used simple ABS plastic instead of the composite material on a final unit for the sake of time and cost reduction.

Mobile mvp

And finally, many IoT products have some sort of connectivity either mobile app or web app. Create an MVP (minimal viable product), don't spend too much time and money on fancy applications. Just get the work done. Connect, get all sensor data in the app and go from there.

Stay tuned for the next video where we’ll talk about Engineering Validation Tests.

More about our Mechanical design: PRODUCT AND MECHANICAL DESIGN

Create product requirements online: SPECIFICATION WIZARD

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