Designing the caster placement
The motors and wheels are near the robot’s front. The caster balances the back, making it a three-point design with two wheels to drive. Batteries are heavy, so putting the caster under and behind them will help balance the robot. We can use the battery box to guide the placement of the caster.
We need to create a LowerParts sketch to place the caster and bolt holes. I’m using a Pololu ¾ inch caster and will use its datasheet/specs as a guide. If you have a different caster, please check its specifications. Pimoroni has a dimensional drawing of this part.
The following screenshot shows the sketch we will make:
Figure 3.21 – The caster sketch
The annotated sketch shows three new circles for the caster’s holes and outline. To sketch this, follow these steps:
- Add the rear line of the chassis as external geometry.
- Draw a circle for the caster outline, with its middle on the vertical...
