Limbi 2019: Assembly Instructions

Authors: Noah Roth, and Ridel Samonte

  1. Parts List
  2. Instructions


This blog post will contain a list of the components required for assembling the Limbi arm, as well as a detailed instruction manual.

Parts List:



  • L2
  1. Top
  2. Bottom

  • L1 and L3 x2
    1. Top
    2. Bottom

  • L0 and L4 x2
    1. Top
    2. Bottom

  • L2 Braces x2

  • L1 and L3 Braces x4

  • Ball Casters x4

  • Servo x6

  • Circular Servo Mount x4

  • Cross Servo Mount x2

  • Cross x2

  • Dock 1 x2

  • Dock 2 x2

  • Cube (Cross Section showing cuts for magnets) x2

  • PCB

  • Push-Pull Solenoid Valve x2

  • Modular Contacts x4


The Limbi arm is symmetrical about the center of limb L2 as can be seen above in the 2D reference. The instructions below shall guide the user to assemble one side, the opposing side will follow the same process.

Step 1)

First install the PCB on the L2 bottom layer using the 4 screw holes located at the corners of the shield.

Step 2)

To install the servos at the ends of L2 (joints 2 or 3) simply place inside the cutouts on either end and mount onto the top layer using the servo mounting screws.

Step 3)

From this point forward the servos shall be assumed to be in place but will not be shown in the images for better clarity.

Once the servos have been mounted in their proper positions the side braces should be mounted at either end utilizing the press fit. For more details regarding press fit please the related blog post. The hooks on the side of the side braces are for cable routing purposes.

Step 4)

We will now begin to mount the next limb L1 or L3. First connect the top layer to the circular servo mount by utilizing the screw holes that have been drilled into piece. The general orientation can be seen below.

Step 5)

Next we attach the bottom layer of L1 or L3 as well as the 2 ball casters that are mounted to the bottom layer for stability and minimization of friction. The ball casters are mounted at opposing ends via the screw holes that go into the bottom layer of the L1 or L3 limb.

Step 6)

You will notice that the bottom layer at the ends of L2 has a cylindrical protrusion that functions as a swivel for the next limb. When attaching the next limb be sure to align the swivel and the hole on the bottom layers as is shown below.

Step 7)

Mount the servo using the in the cutouts in a similar fashion to step 2.

Step 8)

Mount the braces on the sides of L1 or L3 using the press fit method similar to step 3.

Step 9)

Now mount the top layer of L0 or L4 to the circular servo mounts at joints 1 or 4 using the same method outlined in step 4.

Step 10)

The top and bottom layer of L0 or L4 should be oriented as seen below. The docking servo at the end of the arm will be mounted vertically as is shown utilizing the mounting screws. Be sure to mount the swivel at the bottom correctly as well.

Step 11)

We will now mount the docking “cross” component to the servo by utilizing the cross servo mount. This will mount in a fashion similar to step 4 and step 9. The push-pull solenoid valve is mounted on the cross such that the pin extends outside of the hole facing away from the arm as can be seen below.

Step 12)

To assemble the docking layers 1 and 2 we shall first ensure that the modular contacts are properly in place for both the power and ground connections that will be made as the cross locks into place. To mount the docking layers together the press fit method is used at all for corners, as can be seen below.

Step 13)

To ensure proper module-to-module docking ensure that the magnets are properly secured in the 4 place holders within the module block.

This completes the assembly process of one end of the Limbi. Simply repeat the process from step 2 onward for the opposing side for total assembly.