What is the minimum knowledge required for product designer ?

A product designer might be an expert in a field related to the product, versus the mechanical engineer who analyzes and communicates the product design to the manufacturing and ultimately production engineers.

Mechanically speaking, one should be well versed in geometry and trigonometry, and have good visualization skills, for much (if not most) of the work a product designer will do is done inside the mind, away from the computer.

You need to be able to recognize and work with design constraints, the things that 'must be' as these will have a strong influence on the design. Many times parts will seem to design themselves once all the constraints are understood.

Good knowledge of manufacturing processes and their requirements/limitations is also a must, as it is easy to design something that cannot be cost effectively produced.

And of course being good with a CAD tool is also important.

There are only 123 members in the Japan group. I'm surprised none of them answered though.

With all of the impressive models you have uploaded, you are already a product designer.
If you feel you don't have enough knowledge, then you must have the minimum amount required :) But I think it is safe to say that you are far ahead of many other designers already.

There are many different types of designers.
* One type might dream up impractical objects which are very difficult to produce.
* Another might design beautiful products (Many of your designs are this type).
* Still another might focus on designing objects which can be produced in a cost effective manner.
* Others will focus on a specific industry. Cars, jewelry, furniture...etc

It really comes down to the skills, interests, and knowledge that person has, or wants to learn.

You've designed many beautiful objects. If they can't be manufactured as designed, then they will need to be modified a bit. You can learn to do this, or you could work with a partner who is great at production and manufacturing. They should be very happy to receive your models, and make some minor changes, while still retaining the overall aesthetics.

Make it a point to continually educate yourself on all types of manufacturing processes (cnc, injection molding, 3d printing, welding, etc. ). Make sure you expose yourself to emerging technologies and never stop learning.

You're designs look great from the aesthetic standpoint!

I"d say the minimum knowledge requirement is the minimum knowledge that allows you to create 3d designs that match design inputs.

I printed out your comments and put it on the wall !!

I would appreciate if you let me ask you one more question.
What is the difference between industrial design (product design) and design engineering?

To me anyway:

Industrial design:
This is often the design of objects without regard for the manufacturing process. It is very creative work, and great stuff is developed. But, it can cause a lot of friction.
Industrial designers blame the engineers and manufactures for ruining their artwork. Engineers, designers, and manufacturing plants simply can't create (at a cost effective rate) the vision of the industrial designer.

Design engineering:
is similar to industrial design, but products are designed with a focus on being manufactured.

In large firms I believe they can afford to have a team of industrial design dreamers coming up with fantastic ideas to push the boundaries of what is possible. I'd say that industrial design often achieves the best products since there is often a larger development budget (in time, money, resources) for the project. Plus, if the designers, engineers, and manufactures can all work together, you are getting a lot of input from many experts.

Most small companies are going to have a bigger focus on getting a product on the market fast. They need it designed, and ready to be produced. Not designed, then turned over to an engineering team to figure out how to make it.
Sadly, in very small companies, the designer may also be the engineer, and manufacturing expert. Designs can suffer when resources are so limited.

I'm looking forward to seeing how others define these roles.