CHAPTER 19 ■ WHEELSUltrasonic cleaning machines vibrate with ultrasonic (above human hearing) waves. Millions of tiny
bubbles form and pop, scrubbing every crevice of the immersed material.
Use either the cleaning solution designed for the machine or some water with a few drops of liquid
dishwashing soap. Ultrasonic cleaning machines do a fantastic job of scrubbing by themselves. However, the
surfactants in cleaning solutions significantly improve performance by binding the loosened particles to the
fluid, so that they don’t return to the object being cleaned.
Isopropyl or rubbing alcohol may degrade certain rubber and plastics over time. It’s best to avoid using
alcohol on wheels, just in case. You can clean circuit boards using 99% pure isopropyl alcohol. It’s available
at drugstores and supermarkets. Don’t use “rubbing” alcohol or anything less than the full 99% purity, as
oils, perfumes, or damaging chemicals may have been added.
Rolling Along
There are other ways of providing movement for your robot, such as tractor treads and legs. But, wheels are
more likely to result in a successful design when you’re first starting out in the hobby.
Over the years, you’ll probably amass a collection of wheels, just as you’ll amass a collection of motors
and other parts. When a robot idea strikes, you can then lay out the major parts in front of you, swapping
pieces until the robot’s body matches the fuzzy blueprint in your head.
If you’ve chosen LEGO wheels or wheels that have a standard hub, it will be easy to swap different sizes
and shapes, even after the robot is finished. That allows for rapid prototyping and experimentation. In the
next chapter, you’ll learn how to make a coupler to connect any standard LEGO wheel to a motor shaft.
Figure 19-15. Ultrasonic cleaner (middle) with cleaning solution (left) and 99% isopropyl alcohol (right)