Butler Bot

I am a grade 11 student at Oak Bay High School and for my robotics class, I wanted to recreate a spider robot I saw on Aliexpress but with my own twist. After some brainstorming, I loaded up fusion360 and came up with the "Butler Bot", a Bluetooth-controlled crawling robot that can carry things in its hat and wave to you.

Tools:

3d Printer (150*150mm minimum)

needle nose pliers

small screwdriver

android smartphone

wire cutters

sandpaper

Materials:

SG90 servo x8

arduino uno x1

mini breadboard x1

HC-05 bluetooth module x1

12mm googley eyes x2

3.7v Batteries

DuPont connector kit

breadboard wires

hot glue

double sided tape

white and black 3d printer filament

Download and print out all the stls linked below, I printed all my parts at 10% infill to keep everything light

(BB= butler-bot LF= left front RF= right front LB= left back RB= right back)

You will need: 2 of each legs, 2 of each joints, 1 body, 1 hat top, and 1 hat body.

Once you have all your printed parts, remove the supports and clean up all the holes and pegs with a bit of sand paper (just enough that everything moves smoothly)

Once you have all the prints cleaned up, start by putting the servos into place. The wires go through the holes and the drive shaft should be aligned with the peg underneath, then screw them down. (fig1) (fig2)

Next, attach the joint to the leg. The thickest part of the joint should be facing upwards and the flat part of the leg should be facing downwards. When you screw on the servo horn, make sure the servo is positioned at 0 degrees and the bottom of the leg touches the bottom of the joint. (fig3)

After that you are ready to attach the joint to the body. Make sure the servo horn on the leg is facing inwards. Position the body servo 90 degrees, put the joint on at 90 degrees, screw the horn down then add a dab of hot glue to secure the horn to the joint. Repeat the same process for the other 3 legs being mindful of correct orientation. (fig4)

To keep everything organized, use a dab of hot glue to secure the servo wires to the inside of the body, make sure you leave some slack on the leg servos to allow them a full range of motion. After all the wires are secured cut them down to a uniform height, I cut about 5cm off the leg servo wire, and 10cm off the body servo wire (enough that all the wires can still reach the arduino and not take up a ton of space). Once you have your wires cut put male DuPont connectors on all the ends so they can plug straight into your arduino. (fig5) (fig6) (fig7)

Next its time to set up your breadboard, follow the layout in fig8, fig9, fig10.

follow the layout in fig1. You should end up with something like fig2.

download the arduino IDE and the code provide below when you finish installing the arduino IDE, open the butler bot code and upload it to your arduino.

To set up Bluetooth you first need an android phone. go to the play store, search "Bluetooth electronics", and download the one made by keuwlsoft. Open it and click edit on a blank panel. On the right-hand side of the screen, there will be a menu, scroll through and look for "pads". Click on pads and drag a "+" shaped pad onto the workspace. (fig1)

Once you have it in a spot you like click on it and press edit. Change "Up" to "F", "Right" to "R", "Down" to "B" and "Left" to "L", scroll down a bit and select "send continuously while pressed" then press "OK". (fig2) (fig3)

Scroll through the menu again and look for "switches". Click it and drag a switch of your choice onto the workspace. Like the pad click edit on it, change "turn on text" to "W" and leave "turn off text blank". Select "repeat send whilst switch is on" and change the delay to 10000ms. (fig4) (fig5)

When you have the app all set up, you can go ahead and pair, then connect your HC-05 Bluetooth module. (fig6) (fig7)

You're almost there! now it's time to put the googley eyes and hat on. To attach the hat put some double-sided tape where the hat touches the body. Put the googley eyes wherever you feel fitting. To control your bot, firstly make sure the battery is plugged in and charged. Then open the app and connect to your HC-05, when it is connected click on the panel you just made, press "run" and have fun!