# How to design a robot chassis so as to avoid bending issues?

I'm good on the programming, control systems and electronics aspect of robotics, but need help with a problem with mechanical design.

How do I avoid bending of my chassis due to weight? It is a 2 wheeled differential drive robot with a castor wheel in front. Since these are the only three contact points, the chassis is bent along Xand Y axis. What changes can I make to the design to avoid this effect by the bending stress?

• What changes can I make to the design? ... we do not know what your design is ... you provided no information about your robot, other than the number of wheels Jul 19 '20 at 19:40

It is difficult to provide a specific answer due to not knowing details of your design, but consider these factors for the deflection of a beam. They should give you ideas.

For a beam supported at the endpoints, with a load in the center, the deflection increases if:

2. The distance between endpoints increases.

The deflection decreases if the material supporting the load:

1. Has a higher Young’s modulus.
2. Is thicker.

Interestingly, the distance between endpoints very much affects the deflection - all of the other parameters are linear for increasing or decreasing deflection except for the distance. For that parameter, the deflection increases relative to the cube of the distance between endpoints.

So what can you do?