Mechanical Design

This section will provide you some of the design criteria’s and consideration you should keep in mind when developing a mechanical system:

• If possible, develop a mathematical model before ordering parts and prototyping. This will help you determine whether the values you have in mind are suitable enough or not.
• Develop a detailed CAD model of your product early. A visual representation helps in determining shortcomings of the model and allows optimization.
• If your system will experience load, it is always helpful to do a quick simulation to determine the stresses in the system. This helps you determine whether your system will able to sustain the loads applied on it and help you optimize the design. It also helps you to remove redundancies which are taking up space or increasing the weight of the system.
• Some of the mechanism that are commonly used are Lead Screw, Rack and Pinion, One Way Clutch, Belt drive, pulley drive, Gear Reduction for higher torque, solenoid actuation for push-pull, Crank and Slider mechanism and extendable linkages.
• Base your design as much as possible on already available parts instead of engineering yourself. This reduces the human error possible and allows you to concentrate on other aspects of design.
• Always keep a high factor of safety in you design, be it mechanical components, motor selection or sensor accuracy. This helps in reusability of material if you make changes in your design.
• Modular design helps a lot when you encounter failure. If you have a failure in a small part of your system, instead of replacing the whole system and rebuilding it, you can just remove that section. This saves time and money.
• Be ready to reiterate the design. It happens that you build a product and it fails in some aspects. You then try to make that design work by making modification to it over and over again. At one point, the design will get saturated and you will never achieve the expected output. It is important to decide early in the development stage that the design will perform as expected or not. If not, reiterate the design and develop the system from a different perspective. It is a lot of work in the beginning but will prove helpful in the long run.
• Try developing simple systems and mechanical designs for your product. The more complex the design gets the chances of failure increases. Number of components and inter-dependencies between them plays an important role in making the design robust. Minimum number of components and as many independent systems as possible help in improving the reliability and robustness of the system.