Hexapod - Assembly Instructions
The 6 legs of the Hexapod are grouped 3 per side. The right hand (RH) and left hand (LH) legs are a mirror image of each other. Right hand and left hand are always when looking from the back of the hexapod.
The leg assembly is created with 5 printed parts. COXA, FEMUR (x2) TIBIA and Swing Bracket.
The process is the same for the RH and LH legs with just the mirror image applying
The asembly instructions below show the RH legs.
Step 1: Femur Arm - Bearing Side Assembly
The femur bearing side is assembled as shown in the diagram below.
The M5 washer is important to ensure free movement of the bearing.
To aid the bearing fitting into the 3D printed parts its helps to lightly heat the area with a heat gun before pressing the bearings in. this will avoid any load on the 3D printed part which can lead to the part cracking. To ensure a good fit of the bearing an M5 bolt, large washer and nut can be used to press the bearing into the hole by tightening the bolt.
The M5x30 bolt is secured into the bearing in the Tibia and COXA with a nylon M5 lock bolt. Be careful not to over tighten the nut so the arm can move freely.
Step 2: Fan & TIBIA Servo Install
The 30mm fan is attached to the front of the COXA and a 25KG servo to the TIBIA.
The TIBIA 25KG servo can now be installed.
Before attaching the servo arm to the TIBIA we need to ensure the servo is correctly aligned. Attach the 25KG servo to the breakout board and ensure 2S (7.2V) power is running to the servo. The servo will move to the start position. Now the servo arm can be attached using the guide mark on the TIBIA. (Yellow Dotted Line). Do not install the central screw in the servo arm.
Step 3: COXA Assembly
Before installing the bearing in the COXA, lightly warm the area with a heat gun. This will ensure the bearing is inserted without the part cracking.
Attach the servo wire extension wire to the TIBIA servo. Route the cable as shown through the COXA. Also route the 30mm fan wire as shown.
The 35KG servos can now be installed in the COXA. The servo wires should also be routed through the COXA as shown. (no need for any extension cables as the wires are long enough) . To ensure the servo head is in the correct position attach the servo to the breakout board and start the Arduino sketch.
Do not install the central screw in the servo arm.
Step 4: FEMUR Servo Side Install
The FEMUR servo side arm is attached using M3 bolts. The bolts go into the servo head. The arm is then connected to the servo arm using the 4 additional attachment points.
Step 5: Swing Bracket Assembly
Lightly heat the swing bracket bearing hole before pushing in the bearing assembly
Feed all the servos wires through the small hole on in the swing bracket.
By tipping the Swing bracket push it onto the COXA servo head.
To secure the swinging bracket to COXA an 18mm M5 bolt is used.
IMPORTANT: An M5 washer must be positioned between the Swinging Bracket bearing and COXA to ensure a free bearing movement.
To make this possible the swinging bracket can be turned 90degrees to allow access.
This can be a little tricky but with some long nose plyers and patience totally possible :)
The Swinging bracket servo arm can now be secured
Now repeat 2 more times for the RH side and 3 times for the left (mirror)