Advanced Robotics with the Toddler (Paralax, student guide, v1.3, 2004)

Chapter #1: Assembling the Toddler Robot · Page 19

Install two ball joints on the tilting servo control horn (Figure 1-16). Use the outermost two holes for these ball joints.

Figure 1-16

Install ball joints on servo horn.

Page 20 · Advanced Robotics with the Toddler

Step #14: Install Tilting Rods

The following parts are required for this step:

•(2) .090” diameter 5.4” stainless steel rod, 2/56 thread on each end

•(4) ball joint plastic cups with 2/56 thread

Thread two plastic ball joint cups onto the ends of the 5.4” stainless steel rod. Place the rod next to the control horn and foot for sizing. To properly position the ball joints make the finished piece about 1/16” longer than it needs to be as the robot stands straight up; this ensures that the out step of the feet will be firm on the ground and aids with turning.

When you’ve got the length about right, snap the rod onto the foot and servo control horn (Figure 1-17

.

Figure 1-17

Install tilt rods.

Chapter #1: Assembling the Toddler Robot · Page 21

Repeat for the other side.

There is an easy way to remove the ball cups from the ball joint. If you need to make adjustments simply place a screwdriver between the ball cup and the Toddler’s foot and carefully pry (snap) it off. It should pop off and can be pressed back on after you make a few turns to adjust.

Toddler Tuning Tips: Toddler functions best when its body is shifted slightly toward the rear feet. Also, with both servos centered verify that the Toddler’s feed are flat on the ground or that the outsteps are angled slightly downward.

When you’re done with this step your robot should look like the one shown in Figure 1- 18. The Toddler functions best when its body is shifted slightly toward the rear feet.

When you pick up the robot, verify that the robot’s feet are flat on the ground, or that the outsteps are angled slightly downward. Electronically center the servos with the BASIC Stamp again if needed to tune the hardware again.

Page 22 · Advanced Robotics with the Toddler

Figure 1-18

Final installation of tilt rods

Step #15: Install Battery Pack

The following parts are required for this step:

•Battery pack

•(2) 4/40 3/8” long flathead countersunk machine screws

•(2) 4/40 nuts

Stand the Toddler up on its feet.

Install the plastic battery pack using two 4/40 3/8” flathead screws and nuts (Figure 1- 19). The flathead screws will be countersunk into the battery pack when tightened. The screws should be out of the way of the batteries.

Page 24 · Advanced Robotics with the Toddler

Step #16: Install Standoffs

The following parts are required for this step:

•(4) 1” female/female 4/40 standoffs

•(4) 4/40 ¼” panhead machine screws

Using four 4/40 ¼” screws install the four 1” standoffs on the top plate (Figure 1-20).

Figure 1-20

Install standoffs on top plate.

Chapter #1: Assembling the Toddler Robot · Page 25

Step #17: Connect Toddler Board to Battery Pack

The following parts are required for this step:

•Toddler BASIC Stamp printed circuit board

The battery pack’s white lead connects to the Toddler board’s + terminal. The other lead connects to the – terminal. Using a screwdriver secure both wires (Figure 1-21).

Figure 1-21

Connect Toddler board to battery pack.

Page 26 · Advanced Robotics with the Toddler

Step #18: Install 4 AA Batteries

The following parts are required for this step:

•(4) AA batteries (not included in your kit)

Install 4 AA batteries (Figure 1-22). Slide the Toddler’s switch to Position 1 to verify that power is properly connected. The green power light will turn on.

Figure 1-22

Install 4AA batteries.

Chapter #1: Assembling the Toddler Robot · Page 27

Step #19: Mount Toddler Board

The following parts are required for this step:

•(4) 4/40 ¼” panhead machine screws

Using four 4/40 ¼” panhead machine screws mount the Toddler board on the top of the standoffs (Figure 1-23). Connect the bottom servo (stride) to P12 on the Toddler board. Connect the front servo (tilt) to P13 on the Toddler board.

Figure 1-23

Completed Toddler

Page 28 · Advanced Robotics with the Toddler

Step #20: Center Servos Again and Make Adjustments

As a final step, repeat Step #3 to center the servos. The Toddler should stand flat on the ground with both feet aligned. When you pick the robot up, the feet outsteps should be slightly tilted downward. Adjustments can be made to the ball joints. The easiest way to remove the ball joint from the socket is to carefully pry it away from the foot with the screwdriver. Toddlers also walk best when their legs are not vertical – tilt them back one or two degrees so the center of gravity is closer to the middle of the feet.