https://github.com/TheRobotStudio/SO-ARM100

Standard Open Arm 100

• For the SO‑101 docs, follow this page further.
• Here can you find the SO‑100 docs which is depreciated.

You have two options:

• Build it yourself
  • Source the components from the Bill of materials.
  • 3D print the parts (or order the 3D printed parts), explained in Printing the parts.
  • Follow our Assembly Guide.
• Buy a kit
  • Buy assembled arms or a parts kit from one of the vendors here.
  • Optinally follow our Assembly Guide.

After sourcing all parts you can setup your SO-101 with LeRobot tutorial.

This repository also includes a range of optional hardware designs such as a raised leader base and different camera mounts. Here you can explore the full list.

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You can find all optional for SO-100/SO-101 kits here:

• from PartaBot 🇺🇸 US (They include assembled versions, and also sell LeKiwi and Koch robots)
• from Seeed studio 🌍 International or 🇨🇳 China or Aliexpress (They include 3d printed kits)
• from WowRobo 🌍 International or 🇨🇳 China (They include assembled versions)

Additionally you can find SO-100 follower arm kit (without leader arm) on Phospho. It can be especially useful if you own a VR headset.

The follower and leader arm for this teleoperation setup will almost the same off the shelf parts (except for the motors). If you plan on creating the classic teleoperation set up to be used with the LeRobot library please buy from the Parts for Two Arms below.

We only have links for US, EU and CN for now. If you find links for other countries, please create an issue or PR so that we add them to the list. Note that prices and items may vary depending on geographic location.

Part	Amount	Unit Cost (US)	Buy US	Unit Cost (EU)	Buy EU	Unit Cost (RMB)	Buy CN
STS3215 Servo 7.4V, 1/345 gear **2	7	$33.9	Alibaba	€12.2	Alibaba	￥97.72	TaoBao
STS3215 Servo 7.4V, 1/191 gear **2	2	$33.9	Alibaba	€12.2	Alibaba	￥97.72	-
STS3215 Servo 7.4V, 1/147 gear **2	3	$33.9	Alibaba	€12.2	Alibaba	￥97.72	-
Motor Control Board	2	$10.6	Amazon	€11.4	Amazon	￥27	TaoBao
USB-C Cable 2 pcs	1	$7	Amazon	€7	Amazon	￥23.9*2	TaoBao
Power Supply	2	$10	Amazon	€15.7	Amazon	￥22.31	TaoBao
Table Clamp 4pcs	1	$9	Amazon	€9.7	Amazon	￥5.2*4	TaoBao
Screwdriver Set1	1	$6	Amazon	€9	Amazon	￥14.9	TaoBao
Total	---	$470	---	€226.3	---	￥1343.16	---

2: You can buy all six STS3215 servos needed for the SO-101 leader arm
(3 × 1/147 gear, 2 × 1/191 gear, 1 × 1/345 gear) in a single bundle on Alibaba.

Part	Amount	Unit Cost (US)	Buy US	Unit Cost (EU)	Buy EU	Unit Cost (RMB)	Buy CN
STS3215 Servo 7.4V, 1/345 gear	6	$33.9	Alibaba	€12.2	Alibaba	￥97.72	TaoBao
Motor Control Board	1	$10.6	Amazon	€11.4	Amazon	￥27	TaoBao
USB-C Cable 2 pcs	1	$7	Amazon	€7	Amazon	￥23.9	TaoBao
Power Supply	1	$10	Amazon	€15.7	Amazon	￥22.31	TaoBao
Table Clamp 2pcs	1	$5	Amazon	€8	Amazon	￥7.8	TaoBao
Screwdriver Set1	1	$6	Amazon	€9	Amazon	￥14.9	TaoBao
Total	---	$242	---	€124.3	---	￥682.23	---

1: You do not need to use this exact screwdriver set, but it is highly recommended to have phillips head screw driver sizes #0 and #1 for easiest screw installation and removal. These are both standard sizes which will likely appear in most small screwdriver sets.

A variety of 3D printers are acceptable to print the parts necessary of the follower and leader arm. Follow the steps below to ensure a good print.

The STL files provided are ready to print on many FDM printers. Below are the tested and suggested settings though others may work.

1. Material: PLA+
2. Nozzle Diameter and Precision: 0.4mm nozzle diameter at 0.2mm layer height or 0.6mm nozzle at 0.4mm layer height.
3. Infill Density: 15%
4. Sample Printers: Prusa MINI+, UP Plus 2, Creality Ender 3, Bambu Lab A/P/X-series

1. Ensure that the printer is calibrated and the bed level is correctly set using the printer specific instructions.
2. Clean the print bed, making sure it is free from dust, or grease. If cleaning the bed using water, or other liquid, dry the bed.
3. If your printer recommends it, use a standard glue stick and apply a thin, even layer of glue across the print area of the bed. Avoid clumping or uneven application.
4. Load the printer filament using printer specific instructions.
5. Ensure the printer settings match the ones suggested above (most printers have multiple settings so choose the ones that most closely match).
6. Set for supports everywhere but ignore slopes greater than 45 degrees to the horizontal.
7. There should be no supports in the screw holes with horizontal axes.

1. In the Gauges folder, there are two types of gauges, one to check the size of print against a standard 4x2 lego block and one against a STS3215 servo.
   1. If you have a STS3215 servo, print:
      1. Gauge Zero
      2. Gauge Tight
   2. If you have a standard lego block, print:
      1. Gauge Zero
      2. Gauge -0.1
2. Test the gauge 0 against your given object (Lego or Servo). The fit should be similar to this tutorial.
3. If the fit is appropriate, go onto Step 4, otherwise, change your printer settings and try again or create an issue.

All the parts for the leader or follower are for easy 3D printing already contained in a single file, correctly orientated for z upwards to minimize supports.

1. For printer bed sizes of 220mmx220mm (such as the Ender), print these files:
   • Follower
   • Leader
2. For printer bed sizes of 205mm x 250mm (such as the Prusa/Up):
   1. Follower
   2. Leader

This table contains all individual files:

Table

Common Parts

Part	Link
Base_motor_holder_SO101.stl	Base_motor_holder_SO101.stl
Base_SO101.stl	Base_SO101.stl
Motor_holder_SO101_Base.stl	Motor_holder_SO101_Base.stl
Motor_holder_SO101_Wrist.stl	Motor_holder_SO101_Wrist.stl
Under_arm_SO101.stl	Under_arm_SO101.stl
Upper_arm_SO101.stl	Upper_arm_SO101.stl
Rotation_Pitch_SO101.stl	Rotation_Pitch_SO101.stl
Wrist_Roll_Pitch_SO101.stl	Wrist_Roll_Pitch_SO101.stl
WaveShare_Mounting_Plate_SO101.stl	WaveShare_Mounting_Plate_SO101.stl

Leader‑Specific Parts

Part	Link
Handle_SO101.stl	Handle_SO101.stl
Trigger_SO101.stl	Trigger_SO101.stl
Wrist_Roll_SO101.stl	Wrist_Roll_SO101.stl

Follower‑Specific Parts

Part	Link
Moving_Jaw_SO101.stl	Moving_Jaw_SO101.stl
Wrist_Roll_Follower_SO101.stl	Wrist_Roll_Follower_SO101.stl

1. After the print is done, use a putty knife to scrape the the parts off the print bed.
2. Remove any support material from parts.

Go here: Printing services

Extend your SO‑100/SO‑101 with these add ons

Add‑ons

1. Mount Helper

Print the handy mount jig for easier alignment during assembly.

→ View README

2. Overhead Camera Mount

For bird’s‑eye views in single or bi‑manual setups.

→ View README

3. Raised Leader Base

Lift your leader arm for low‑ground tasks.

→ Download STL

4. Tactile Sensing (AnySkin)

Add touch sensing to your gripper.

→ Find on WOWROBO

5. Wrist‑Mount Cameras

Webcam (Vinmooog)	32×32 UVC Module	32×32 UVC Plug‑on	RealSense D405
Instructions	Instructions	Instructions	Instructions

For debugging, any Windows PC can connect over USB to program the servos and to debug or do tests. To do so download Feetech Software. For Ubuntu, you can use FT_SCServo_Debug_Qt. Note: This step is not necessary as motors can be configured using the LeRobot Library, but this can be helpful for debugging.