robotic snail

Line Trace Snail Kit Review

Assembly Time: 2-3 hours
Skill Level: Intermediate

Have you ever wanted a pet snail that would follow your command? Well, now is your chance! Construct your very own robotic snail that can move wherever you tell it to go! This snail uses a light detection sensor that can identify a black line that you draw with a marker. With this capability, you can also race two or more snails! This easy-to-build snail is perfect electronics project for everyday fun!

Materials included in kit:
1 Snail base
1 Snail cover
1 Sensor unit with attached motors and wires
2 Battery Terminal A
1 Battery Terminal B
2 Battery Terminal C
1 Tube of grease
2 Tires
2 Worm gears
7 Tapping screws
2 Rivets
1 Metal shaft
1 Plastic rivet
1 Rubber tubing
2 Gears
2 Gearshafts with attached gear
A1 - A12 Pieces
snail parts
snail schematic

Building the snail kit

1. Carefully take out all the parts from the box and snap off the plastic parts from the holder. (Remember which number on the plastic holder corresponds to which part.) (WARNING: ALL PARTS ARE VERY FRAGILE AND COULD BREAK EASILY.)

2. Place the worm gear on the peg of each motor. (There should be about 3 mm of space left between the worm gear and the rest of the motor. You can use the gap in the base of the snail for measuring as seen in the picture.)

mounnted worm gear
3. Attach a tire to each A8 piece. Then insert a rivet in each gear (already attached to the gearshaft) in the opposite direction of where the gearshaft is pointing. (See diagram.) Next, attach a gearshaft to each A8 piece. With all of those parts together, insert the rivets into the A4 and the A5 pieces. (You may need to use needle-nose pliers to press the A4 and A5 pieces into the rivets.)

snail chassis schematic
4. Insert the metal shaft into part A10. Then insert each side of the metal shaft into a gear so the knob of the gear is touching part A10. Next, place each side of the metal shaft into the slots on the snail base. (See diagram.)

5. Insert each battery terminal A piece into the slits in the battery slots. Next, insert each battery terminal C piece with the dot in the top left corner of the pieces in the little slits at the end of the battery slots. (You may have to press down on the battery terminal C pieces to get them into the slits. They should also hold the battery terminal A pieces into place.) Then insert battery terminal B into the slits on the other side of the battery slots so the knobs are facing into the battery slots.

6. Place the contraption that you made in step 3 into the snail base by inserting the metal bar into the slots with the wheels pointing out. Next, place the A6 and the A7 pieces on the space that holds all metal bars. (The location should be obvious due to the matching shape.) Then, using a Phillips head screwdriver, screw 1 tapping screw in the holes of each A6 and A7 piece until they are tight.

7. Place the A12 piece on the front of the snail base by inserting its tab into the slot. Next, use a Phillips head screwdriver to screw a tapping screw through the slot of the A12 piece and through the hole of the snail base.
assembly schematic
snail base assembly

adding snail chassis and sensor base
attach sensor 8. (This is a complex procedure, so make sure to look at the pictures for help.) Flip the snail base over. Insert the sensor base of the sensor unit into the opening in the snail base. With 1 A2 piece over each hole of the sensor base, screw a tapping screw through all holes. Then insert the plastic rivet into the other hole on the front of the snail base. (It should snap in.)
9. With the main base of the sensor unit in place, fit the white wire in the compartment of the A12 piece. Then screw a tapping screw into each hole of the main base of the sensor unit until it is tight.

10. (Make sure the gears of the wheels are pointing in opposite directions to make the snail look cool as it moves.) Place the motors in the slots so the R motor is on the right side of the snail base and vice versa. Next, gently position the two plastic A4 and A5 pieces down over the sensor unit. Then, place the A3 piece over the two motors and insert it into the slot between the two motors. (Make sure the perpendicular piece from the A3 piece is pointing towards the front of the snail base.)

11. Snap the A1 and A2 pieces into place on the front of the snail base.

snail's eye assembly
12. Take off the rubber covers of the red and black wires. Insert the metal part of the wires into their specific holes of the battery terminal A pieces. With scissors, cut two 3mm long pieces off of the rubber tubing. Push a 3mm long rubber tube onto each metal knob to cover the metal part of the red and black wires.

13. Place AA batteries into the battery slots in their specific direction.

14. Insert the A9 piece into the hole of the snail base when not needed. Snap the snail cover into place as shown.

wiring schematic and parts

Operating the snail kit

completed robotic snail 1. Lift tires 0.5cm off of a white surface.

2. Turn the red switch to the "on" position.

3. Use the A9 piece to turn the sensor adjuster all the way counter clockwise. (The right wheel should be spinning.)

4. While still on, slowly turn the sensor adjuster clockwise until the right wheel stops spinning and the left one starts to spin.

5. With a fat marker, draw a line on the white paper. (The black line has to be at least 3mm thick. Also, curves in the path have to be gradual turns instead of sharp ones.)

Notes • Lasts for 2 - 3 hours.
• If snail stops operating, check the black rubber tubes that hold the red and black wires into place. They must be fully on the metal knobs.
• Yes, the noise is annoying, but have you ever heard a snail make that kind of noise? I think not!
• Before each use, always adjust the sensor adjuster with the A9 piece.

This project was assembled by Ari Dubinsky. Ari is attending Cal Poly San Luis Obispo, pursuing a degree in Electrical Engineering. Ari has teamed up with Jameco to accelerate his learning as well as to lend a helping hand to a major electronics distributor. His interests include shredding on the guitar, martial arts, and music production.