Robotic Drives & Physics: Robotics, learn by building III

We take a look at the different components and parts in the available kit and explore different options for the parts used in this course.

This is just a walk-through on assembling the table in the Physics experimenter's kit.

To kick off this course, we'll start with simple machines: Levers. Levers and mechanical advantage provide an important and often overlooked aspect in robotics.

We will now build a gear drive on our physics experimenter's board (or on a board, if you're using your own parts) in preparation for the next lessons.

After giving the solutions to the gear drive questions of the previous lesson, you are presented with another mechanical challenge.

After giving the solution to the mechanical mayhem challenge #1, we explore a mechanism called the strap drive.

We'll now apply our knowledge of levers in designing an arm robot to calculate its ratings and reach.

Part 2 in designing an arm robot

Let's now take a moment to learn about the arch nemesis of robotics: backlash. What it is and how it affects our robots.

We'll now take a look at the simple machine the wedge and threads, examining the physics of this very powerful drive mechanism. We will also take a first hand look at its use in an industrial robot.

After learning of backlash (the arch-nemesis of robotics and automated manufacturing machines) here we take a quick look at a couple of solutions that have been presented by engineers over the years.

Let us now explore the basic operation of brushed DC motors, probably the most common type of electric motor you will use or encounter.

After studying how a DC motor works, we take a tour of an electric forklift so we can see first hand the different types of exciter winding DC motors and how to identify them.

So just what is Back EMF anyway? Why should we care?

Now with 3D printable files! Thanks to student Paul March who so kindly produced the files and willingly shared them with all of us. They are downloadable as a ZIP file in the downloads section - thanks Paul!

In this lesson, we'll get a preview of the toggle mechanism which will repeatedly come up in the most unexpected places. Oh, we'll also build a robot gripper using the toggle mechanism.

Let's take a walk through electrical generation as this will be a handy tool we'll use later on - and it'll explain what three phase AC power is, and all of these "angles" they keep talking about in electricity.

In this lesson we'll make use of our gear drive to turn a DC motor into a generator and then look at the possibilities of what we can do with such a system.

In this lesson we'll take a look at how to practically apply regenerative braking in an electric vehicle.

In this lesson, we ask the question "What is a servo?" and explore various feedback methods and some hardware hacker techniques for making feedback devices in your home shop.

In part 2, we will continue to look at various forms of feedback found in servo systems.

We'll explore the first of several motors in the "brushless" category: the stepper motor

Now let's use our Arduino to actually drive our stepper motor around.

A clarification for the wiring on the brushless motors we will use in the next several lessons.

In this lecture we will build the 3 phase H-bridge needed to drive our BLDC as well as look at the Arduino sketch used to drive the motor.

Next we take driving our BLDC to the next level by driving the motor in response to closed loop feedback from the on board hall effect sensors.

We'll take a quick look at the theory behind generating a pseudo sine wave using PWM

They said it couldn't be done! Or maybe they said it shouldn't be done - I dunno, I wasn't really paying that much attention at the time. I did it anyway! Now you're going to do it. We're going to take a standard brushless DC motor and hardware hack it into an AC servo motor which is a very common, precision drive used in industrial robots and automated machinery.

Part 2 of hacking a common brushless DC motor and turning into an AC servo motor. And they said it couldn't be done!

In this lesson we will lay out the demands for the design and construction of a free-floating, submarine ROV to be used as a case study in designing and constructing such an ROV.

We'll take a look at the first physics challenge of designing an underwater robot: controlling buoyancy

In part 3 of this design case study, we will examine the complexities of density and submarine robot design.

In this lesson, we take a look at the physics involved in pressure vessels and specifically the design failures in a submarine ROV and how to get around them.

In this lesson, we explore one of the more esoteric robotic drives called the harmonic drive.

Another esoteric drive mechanism which can be built in your home shop

Your skillset is now becoming dangerous. We gotta talk safety, especially in regards to industrial robots with which hopefully many of you will tangle.

So many students requested information on building electric vehicles that I thought we would take a look at a large, hybrid electric vehicle: A freight train. We'll look specifically at the dynamic braking system as well as the unusual story of a runaway freight train in Ohio which got away specifically because of the dynamic braking system. We'll apply this to electric vehicle design.

We will now further explore the power of AC drive motors in electric vehicles, again looking to freight trains and their fairly recent use of AC traction motors, their advantages and disadvantages.

As we move on into pneumatics and hydraulics, we'll take a quick crash course on safety.

We'll start assembling the backboard parts to use in the next several lessons. Here's part 1.

The stockpile of original pumps I was using has been expended. Here is the updated instructions for the new pump.

Part 2 of the assembly instructions for the backboard in the Physics Experimenter's kit.

Now we'll assemble an air tank for the physics experimenter's kit.

We'll walk through the steps in assembling our power cylinders.

We'll take a look at the specific design of the power cylinders and some parts that were included for future use in your robots.

We'll conduct a tear-down of one of the very first home-built power cylinders I ever made about 25 years ago. I'll walk you through the construction and give tips on how you can build your own power cylinders.

In this lesson we'll learn the physics behind power cylinders, and how to calculate the force they will produce.

A quick introduction to the venerable solenoid which we will use next, and you will encounter often.

Now we'll plumb together our first pneumatic circuit and operate the air cylinders to get a grasp of a basic pneumatic circuit and why it's plumbed the way it is.

We'll now experiment with our air cylinders to see how close we can get to our predicted forces and see and experience the limitations of our predictions.

In this lesson we build and use an air muscle.

An oft overlooked part of robotics design is counterbalancing the weight of the robot itself. Here we'll take a look at why you should at least take it into consideration.

We'll take a brief look at the simple but important physics of springs, and then practical applications of that knowledge including a fairly extensive look into animatronic mechanisms.

We'll take a quick look at another form of positional feedback. A device called a resolver.

After learning what a resolver is, we look at how to use a comparator with hysteresis combined with a microcontroller to calculate our position