Author: McMahon, Pat

How to Build your Infrared Hexapod Robot

Pat McMahon– V4– 2/4/2017

Design Brief – Using a laser Cutter, design and cut out the Hexapod Parts on Acrylic or ply, constructing your Infrared Controlled 14M2 Picaxe Hexapod Robot.

Note – The photos taken in this “How to Build” are using 3 mm thick Plywood. The same can be done using 3mm coloured acrylic on the Laser.
cutter, like the green acrylic Hexapod in the photo below.

3 mm Plywood

3 mm Acrylic

Below are some of the Production Steps, you can use your own design, Tick off each box as you complete a task and Document it.
Tools Required– Soldering Iron, Side Cutters, Pointy Nose Pliers, Phillips Head Screwdrivers, Glue, Tape.
NOTE– Nyloc nuts are supplied to lock without over tightening, leave all connections free of any friction, back off all tightened nuts.

Check, you will need M3 Pan Head Metal Threads & nuts.
8 – M3x 35 mm
10 – M3x 16 mm
20 – M3x 10 mm
38 – M3 Nyloc Nuts

Carefully using a Stanley Knife / PVC Pipe cutter, cut

7mm diameter Plastic Riser Tube Spacers-
8 x 24 mm long Spacers
2 x 10 mm long Spacers

Design & Cut your Laser Parts.
(300 mm x 40 mm x 2 mm)

Glue the 8 Outer Link Arms to the 4 Outer Legs, ensuring perpendicular and pushed firmly home. ( Super Glue for Ply or “Weld On 16 “ for Acrylic )

Press fit the 2 Centre Spacer Blocks in Bottom Plate

Top

Bottom

Insert 12 M3 x 10 in Top & Bottom Plates, using Servo Motor rubber mounts to hold in place.

IMPORTANT-
Ensure servos are mounted under Top Plate and between Bottom Plate, Servo Brand sign to the front, wires to the rear.

Top Side

Page 2

Pat McMahon– V4– 2/4/2017

Mount & fasten the 3 Servos
Ensure servos are in between the Top & Bottom Plates.
(40mmx20mmx39mm)
Servos, correct side up

Pass Servo leads through the spacer blocks

Attach top to base with press fit.

Ensure top & bottom plates are parallel.

Run leads out rear top plate hole & Mark servo No’s.
& Cut ~120mm from the plastic end & mark the white/yellow wire with marks for servo No 1, 2 or 3.
Cut 140mm from the plat

3

1

2

Use M3 x 35 Metal Threads & nuts, to fasten the 8 plastic spacers.

Don’t over tighten.

Make up 2 opposite inner Hook assemblies using M3 x16 metal threads & nuts, with the heads facing towards the front.

Ensure both Hook link Arms are in between the spacer Blocks, in similar relative positions & fasten loosely.

Attach 4 outer leg assemblies with 8 -M3 x 10 & Nuts Ensuring they are mounted under the Top & Bottom Plate, freely.

CCck for ease of swing

Ensure ease of swing by backing off the nut adjustment.

Page 3

Pat McMahon– V4– 2/4/2017

Rotate Servo Arm until two holes line up.

Use Servo supplied self tappers to fasten Servo Arms.

Don’t fasten arms to servos, until you turn on the microcontroller to centre. Servo shaft has 24 splines,
15 degrees for each spline rotation.

Attach the 6 connecting rods, perpendicular as below.
Keep as horizontal as possible, top of legs, bottom of arms.

Pass all the wire leads, out rear opening before connecting and soldering.

To fit wire rods, you will need to temporarily remove the servo arm & replace when rods are in the holes, in place.

Bottom
of Arms

Top
of Legs

If inserting LED’s, temporarily solder & build on top, connecting wires, insulate, remove & insert with tape underneath.

LED’s up side down

Insulate with tape

Remove & insert LED’s from underneath & tape up

Solder Black /Brown negatives (3 Servo + 2 LED + 1 extra PCB Wire) all 6 together.

Solder Red positives (3 Servo + 1 extra PCB Wire) all 4 together. Keep White/Yellow output wires single & separate, ensuring marked with servo No’s, 1, 2 & 3.

Note—The reason for grouping all the wires together and only having 1 set of Extra PCB wire is because all 6 won’t fit into one PCB Doughnut pad.

Trim and put tape or Heat shrink around the ends of the wires, to stop shorting.

If using Heat Shrink, heat to Shrink with mini blow torch.

Skip pin 0, putting the servo output signal white/yellow wires, servo 1 in pin 1, servo 2 in pin 2 & servo 3 in pin3.

Solder positives from LED’s into C.0 (front LED’s) & C.1 (Back LED’s)

Pin 1, 2 & 3
(Not pin 0)

Pin C.0

Pin C.1

Page 4

Pat McMahon– V4– 2/4/2017

Solder Extra PCB wires in PCB.

Insert the extra Red PCB wire to one of the Positives (+)

Insert the Black extra PCB wire, in the Negative(—) doughnut pad, through the tug hole.

Replace screw and spacer. It should be a tight fit to stop the Battery Box moving around.

Remove back right screw & insert the 6v Battery Box ( with batteries installed, & turned off) between legs, switch end first, feeding + & - up through back opening.

Slide in Battery Box filled with 4 x 1.5 V AA Batteries.

Join the Battery Box + & - wires to the 14M2.

After ensuring all wires are connected together & protected, using two 10mm long plastic riser tube spacers, attach 14M2 with two M3x16 screws and nuts.

Program using Picaxe “Programming Editor”.

Test your program and adjust the throw of the servos in the program, for correct leg movement.

Once you have mastered the movement, try programming the Universal Remote M for the actions below-

Forwards (infra=116)

Left (infra=52)

Right (infra=51)

Back to Centre
(infra=101)

Backwards (infra=117)

Note—The Infra= commands above, are for the Universal Remote M (LR-LCD 708E). If you are using a different Universal Remote you will need to find and change the infra= commands.

Well Done!
Congratulations for persevering to build, test, modify and program/code your own Infrared Controlled Picaxe 14M2 Hexapod Robot.

Page 5

Some additional Hints that might help students minimise any possible errors.

Pat McMahon 8/9/2024

A closer view for the correct connection of the linkage Rods. You need to first hook the linkage Rods to the outer legs as shown. Then with the servo arm removed, twist it so as to fit the Rods to the end to the servo arm. Once inserted and the servo is at the neutral 90 degree, press the arm on the servo and fasten it with the servo screw.

A closer view for the correct connection of the L shape underneath acrylic middle leg. Using M3 16mm bolts with the heads to the front and the L Shape facing to the rear, loosely secure with the M3 Nyloc Nut, ensuring free movement.

A closer view for the correct connection of the underneath linkage Rods. You need to first hook the linkage Rods to the L Shape acrylic as shown. Then with the servo arm removed, twist it so as to fit the Rods to the end to the servo arm. Once inserted and the servo is at the neutral 90 degree position, press the arm on the servo and fasten it with the servo screw.

A closer view for the correct connection of the acrylic arm to the servo horn (Disc). Using the screws supplied with the servo, connect the top hole of the acrylic arm to the centre hole on the top of the disc. Align and repeat for the remaining others as below.

Unfortunately some Screws supplied are too long and stick out, stopping the rotation of the servo when attached, hence possibly burning out the servo
Using a Dremel or similar device, trim the excess end of the screw.

A closer view for the correct connection of the acrylic arm to the servo horn (Disc).

Page 6

Helpful Equipment when Building your Hexapod Robot

Pat McMahon V1 10/9/2024

A Servo Tester checks the correct operation of the servo movement and more importantly, the resting or 90 degrees position for the correct alignment of the Servo Arms to the Linkage Rods.

A 5.5mm Hex Socket for the M3 Nyloc Nuts makes assembly of the 38 x M3 Nuts with a Phillips head screwdriver at the other end, a lot easier.

If for some reason it is necessary to remove one of the servo motors, once the Hexapod is fully assembled, I have made a special tool. It holds and stops the M3 Nut from rotating in tight places, for removal and assembly, hence being able to remove and replace the Servo if necessary.