Non-standard mechanical design involves a wide range of work, because the nature of the profession is to solve all aspects of the problem, so non-standard designers are required to have a wide range of knowledge and knowledge. The more knowledge, the more effective the work, the more knowledge, the more experience, the more ways to solve the problem, the faster and more accurate. The following are major mistakes that cannot be made in non-standard mechanical design.

1. Design against the permission of laws and regulations

2. Matters not in conformity with the contract or decided by internal meetings with customers and companies

3. No design basis (excluding experiential design or feasible innovative design or inventive design)

4. Failure to meet functional and productive requirements

5. can not be disassembled

6. Major mistakes in selection

7. Making mistakes in material selection of important components

8. Major errors occurred in the formulas and parameters in the calculation book.

9. Major errors in size, elevation, coordinates, etc.

10. Serious interference

11. Excessive affluence in equipment capabilities

12. There are potential safety hazards