Gravity Bugs: Step-By-Step Guide

Before you begin:

Take out the plastic frames and parts from the box.

Take a moment to look closely at the plastic frames and notice that each section has a number that corresponds to the number of the part. Remove all the parts from the frames only when they are needed. 

Also take a moment to distinguish the fully threaded screws (you should have seven) from the half-threaded screw. This will be useful later!

Gather the other items you will need for this assembly:

  • Small Phillips head screwdriver
  • Diagonally cutting pliers or scissors and nail file.
  • AAA battery

Important tips:

  • Remove all the parts from the frames only when they are needed. 
  • You must carefully cut the plastic parts out of their frames with diagonal cutting pliers or scissors (cutting tool).
  • Remove excess material (burrs) from the parts before assembling them. Normal scissors do not cut as precisely as diagonal cutters, so you might have to file some of the rough edges down with a nail file.

Note: It is especially important to remove burrs from the gray gear pieces. Burrs are pieces leftover from removing the parts from the frame that will cause resistance, preventing the gears from rotating freely. This can cause the gears to come out of alignment, or worse, cause the gears to wear each other down.

Time to build! For a complete Step-By-Step Assembly Guide you can follow along with the video in its entirety OR jump to a specific step below.

STEP 1

Carefully remove part 22 from the green plastic frame with a cutting tool. Then, remove all burrs completely with a cutting tool.On the battery box (part 22), pay attention to which side is positive and which side is negative. 

 

Identify the parts of the motor and switch circuit. It is important that the battery box be assembled in the following order:

  1. positive terminal (attached to red wire)
  2. negative terminal (attached to black wire)
  3. switch
  4. motor


Insert the red wire into the channel on the left side of the battery box, next to the ⊕ battery symbol. 

Make sure the round protrusion of the positive terminal is facing inward.

STEP 2: 

Remove part 14 from the gray plastic frame.

Use one of the prongs of part 14 as a tool to push the positive terminal all the way into the slot.

When you are done with this step, approximately ⅛ inch of the metal tab should be sticking out of the slot.

STEP 3:

Use part 14 to bend the metal tab toward the outer edge of the battery box.

STEP 4:

Insert the black wire into the channel on the other side of the battery box, next to the ⊖ side of the battery box. 

STEP 5:

Use part 14 to push the negative terminal all the way into the slot. 

STEP 6:

Use the tool to bend the metal tab toward the outer edge of the battery box.

STEP 7:

Insert the switch into the hole.

Make sure the wires are not twisted here. The red wire should be on the side of the positive terminal and the white wire should be on the side of the negative terminal.

STEP 8:

Insert the white wire into the channel in the battery box. Use part 14 to push the wire all the way down, so that it fits snugly in the channel. 

STEP 9:

Place the motor into the motor compartment above the white wire. Slide the motor toward the center of the battery box until it meets the resistance of the box. 

After this step, the motor gear should turn freely and should not touch the white wire. If the wire is in the way, go back to step 8.

Set this subassembly aside.

STEP 10:

Remove the four suction cup caps (part 6) from the blue plastic frame, and remove any burrs.

Confirm there is no dust or debris in the tops of the green suction cups.

Place the green suction cups in the blue suction cup caps.

Check the bottoms of each of the suction cups. There should be an even gap between the suction cup and the cap.

STEP 11:

With a cutting tool, carefully remove the four part 20 pieces from the green plastic frame, then remove all of the burrs. 

Align each part with the top of each blue suction cup cap and press firmly, until you hear a click.

STEP 12:

Remove parts 4 and 8 from the blue plastic frame (there are four pieces of each part), then remove all of the burrs.

Make sure part 8 is fully inserted into the top of the suction cup.

Place the parts flat on the table, with the green suction cup facing up. Place part 4 in the circular opening in the suction cup with the flat side down, as shown.

STEP 13:

Take out four fully threaded screws. Be careful not to use the half-threaded screw.

With the parts flat on the table, make sure there is no gap between the blue plastic parts. Then screw together.

Repeat for the remaining three feet. Set these subassemblies aside.

STEP 14:

Assemble the head by connecting parts 2 and 19 as shown. Set this subassembly aside.

STEP 15:

Remove part 1 from the blue plastic frame, and remove any burrs. 

Attach part 1 to part 14 as shown. Be sure to have the symbol on part 14 facing upward. The notch on part 1 lines up with the notch on part 14.

Part 14 is used to help you align the gears. Set this aside for now. 

STEP 16:

Remove part 5 and part 11. (Notice part 5 has four protrusions, whereas part 1 does not).

Attach part 5 to part 11, as shown. Be sure to have the symbol on part 11 facing upward. The notch on part 5 lines up with the notch on part 11.

Part 11 is used to help you align the gears.

STEP 17:


It is very helpful to work on a tabletop. Orient the part so that the notch is closest to you.

Place the two long metal rods and the short metal rod into the holes on part 5, as shown.

STEP 18:

With your cutting tool, carefully remove P5 and two part 10 parts from the gray plastic frame. 

Carefully remove any burrs. You may need to use a nail file or sandpaper to smooth the edge of the gear pieces.

Note: The edges of the gear pieces need to be smooth and free of burrs for the Gravity Bug to function properly.

It is best to trim burrs with your cutting tool parallel to the burr, as shown.


Take a moment to notice the subtle differences between parts 9, 10 and 13. 

  • Part 10 has both circular and rectangular columns
  • Part 9 has only a circular column
  • Part 13 has only a rectangular column

Place the circular column of part 10 into the hole of part 11 as shown. Repeat on the other side. The rectangular columns of part 10 should be facing up at this point.

Place the P5 gear on top of the short metal rod. 

STEP 19:

With your cutting tool, carefully remove two part 9 parts from the gray plastic frame. Carefully remove any burrs. 

Place the circular column of part 9 into the hole of part 11 as shown. Confirm that the gears lie flat.

Place a white gear (P6) on top of the long metal rod in the middle of the gearbox. 

Make sure the gears are correctly seated. At this point, the teeth of P5 should mesh with the teeth of P6 and the gears should turn easily.

STEP 20:

With your cutting tool, carefully remove two part 12 parts from the gray plastic frame. Carefully remove any burrs.

Place part 12 with the gears facing down on the blue pegs of part 5.

Place the second white gear (P6) on top of the long metal rod furthest from you. 

At this point, the second white gear should mesh with the teeth of the first white gear, and all three gears in the middle of the gearbox should turn together.

In addition, the teeth of part 12 should mesh with the teeth of parts 9 and 10, but the gears will not turn, because they are locked in place by the alignment tool (part 11). 

STEP 21:

Remove the two part 3 parts from the blue frame and place them on top of the blue pegs of part 5 as shown.

Place the third white gear (P6) on the long metal rod in the middle of the gearbox as shown.

The teeth of the third white gear should mesh with the teeth of the second white gear, and now all four gears in the middle of the gearbox should turn together.

STEP 22:

Insert the battery box into the body frame. Orient the battery box so that the motor is on the right and the switch is on the left. The battery compartment should be facing outward. Make sure the tabs on the sides of the battery box slide into the grooves of part 5. At this point the tabs on the battery box will be half covered by the frame.

Use a screwdriver to tuck the wires inside the frame and move them out of the way of the holes. This will ensure that the wires are not pinched when you close the frame later.

STEP 23:

Remove the two part 15 parts and insert them into the rectangular holes of part 10.

Place the fourth and final white gear on top of the long metal rod furthest from you. 

Make the teeth of the fourth white gear mesh with the teeth of the third white gear.

STEP 24:

You must assemble the parts in the correct order for this step. 

With your cutting tool, carefully remove the two part 13 parts and the two remaining part 12 parts from the gray plastic frame. Carefully remove any burrs. 

With the rectangular columns facing down, place the part 13 parts on the rectangular rods (part 15).

Then, place part 12, with the gears facing up, on top of the blue plastic pegs (part 3).

The teeth of part 13 parts should mesh with the teeth of the fourth white gear. The gears will not turn at this point because they are locked in place.

STEP 25:

With your cutting tool, carefully remove the two remaining part 10 parts from the gray plastic frame. Carefully remove any burrs. 

With the rectangular columns of part 10 facing down, place on the rectangular rods (part 15). The circular columns of part 10 should be closer to the middle of the gearbox.

At this point, the teeth of part 10 should mesh with the teeth of part 12. Check to see that everything is in place. The gears will not turn at this point because they are locked in place.

STEP 26:

 

With your cutting tool, carefully remove the two remaining part 9 parts from the gray plastic frame. Carefully remove any burrs. 

Place the circular columns of the part 9 parts into the holes of part 14. Press the gears firmly into place (this can be a tight fit).

STEP 27:

Before putting the two blue body pieces together, double check that the wires from the battery box are tucked in.

Place the upper body half on the lower body half. 

Make sure...

  • The groves on the upper body half slide onto the tabs of the battery box
  • There are no gaps between the halves of the body
  • No wires are clamped

STEP 28:

Remove the alignment tool (part 14) by lifting straight up so that you don’t disturb the gears.

STEP 29:

Find the three remaining fully threaded screws and screw them into the holes on the top of the body.

Don’t over-tighten the screws. If the gears don’t turn when you test after step 32, loosen these screws a little.

STEP 30:

Remove the second alignment tool (part 11).

STEP 31:

Insert a AAA battery with the correct polarity (+ and -). Note the polarity markings inside the battery box.

Turn the switch on to make sure the gears turn. The four grey circular columns on each side of the body should now be moving in unison. 

STEP 32:

Remove part 23 and insert the tabs of the battery compartment cover into the slots of the battery box.

Now it’s time to use the half-threaded screw!

Screw the battery compartment cover to the battery box with the half-threaded screw.

STEP 33:

Remove parts 16 and parts 18 from the green frame, then remove any burrs. Also remove the eight locking pins (part 7) from the blue frame.

Attach the two legs with four locking bolts onto each side of the body.

STEP 34:

Lock each bolt in place by using one prong of part 14 as a screwdriver. Turn the bolt counterclockwise until it clicks to lock it. (Turn the bolt counterclockwise to unlock.)

You might find it necessary to use part 11 one side to lock the gears in place while you secure the legs.

Repeat steps 33 and 34 on the other side.

STEP 35:

Attach the four suction cup feet to the legs. Pay attention to the direction of the arrow pattern on the tops of the feet when sliding the feet onto the legs.

Turn on the gravity bug to test that the legs move. If the legs don’t rotate when the power is on, don’t panic! Disassemble the model, carefully trim the burrs from the gray gears and reassemble. You can do it! 

STEP 36-37:

Attach the two remaining legs (part 17) to either side of the body.

STEP 38:

Attach the head on the side closest to the switch.

Pay attention to the direction. The largest circle on the head should be pointed toward the top of the bug.

STEP 39:

Attach the green outer shell (part 21) to the two blue pegs on the bug’s back.

Pay attention to the orientation. The pointed part of the green shell should point to the bug’s head.

You are done!

To get the best performance out of your Gravity Bug, try adding a drop of oil to each of the eight gears that connect to the legs. Olive oil will work fine.

Experiment with your Gravity Bug

First, test out your Gravity Bug on a smooth, horizontal surface, like a tabletop. Turn it on and it should walk forward.

Then, stick it to a smooth, vertical surface like a large glass window. Press the suction cups firmly to the surface. The surface must be extremely smooth.

Make sure the surface is clean and dust-free. Cleaning the suction cups or the surface with water can also improve the robot’s grip.

Turn on the switch and watch the robot climb. Keep your hands below the robot to catch it if it falls.

Experiment to see which surfaces your Gravity Bug can climb!

If you’re still having trouble…

Our tech support team would be glad to help you!

USA: support@thamesandkosmos.com or 1-800-587-2872

UK: support@thamesandkosmos.co.uk or 01580713000