comparison · Source researched

SO-101 follower or leader–follower: what changes in the parts list?

The documented leader–follower setup adds a second arm with mixed servo gearing and a second controller connection. A follower-only list omits that input arm; decide how you will command the follower before ordering.

For: Builders planning a first source-documented robot configuration

Scope: Source research only; pinned configuration and recorded cost inputs. Current seller prices, electrical validation and physical reproduction are outside this guide.

By Open Source Robotics editorial team · Sources checked 2026-10-07 · Updated 2026-10-07

Choose the control setup before ordering

For the documented two-arm teleoperation setup, you move the leader and the follower reproduces its motion. A follower-only purchase leaves out that physical input arm. Choose the pair if your intended workflow is the upstream leader–follower setup; choose follower-only only after identifying how you will command it. This comparison does not establish an alternative controller or a trained policy. Hardware instructions

What changes in the parts list

The pinned hardware README distinguishes these quantities. “C001”, “C044” and “C046” identify different listed servo variants; buying twelve identically named servos does not reproduce its mixed leader configuration. Hardware BOM Leader joint table

The leader joint table assigns 1/191 gearing to shoulder pan and elbow flex, 1/345 to shoulder lift, and 1/147 to wrist flex, wrist roll and gripper. That distribution accounts for the six additional motors in the pair. Assembly instructions

Do not turn the quantity table into a power recommendation

The hardware README discusses both 7.4 V and 12 V follower variants and a different supply for the 12 V option. This guide covers the quantity comparison for its nominal 7.4 V configuration. The retained cost excerpt lists a 5 V supply and a generic control board. Electrical compatibility and the exact controller identity remain unverified in this guide. Confirm the exact motor and controller specifications before powering a setup. Hardware voltage note Retained cost inputs

What is shared, and what the budget still needs

The October 4 cost sheet lists the host computer and suitable screwdrivers in its requirement layers. A printer is required only for self-printing; the sheet also identifies printing services as an alternative. Owning suitable equipment changes what you need to buy. The assembly instructions call for M2×6 and M3×6 screws, while the reviewed cost sheet leaves their complete sourcing unresolved. Printing, fasteners, delivery and tax deserve their own checks rather than disappearing behind the servo count. Cost scope Assembly fasteners

The existing cost sheet has separate follower and pair configurations, with dated inputs and explicit scope notes. Use it to inspect scope and quantities; this guide has not refreshed seller prices and makes no current checkout-price claim. Open the SO-101 cost breakdown.

Check your chosen configuration

Write down follower-only or leader–follower, the exact servo codes, and the hardware/software revisions before assembling a shopping list. Then compare that list with the pinned assembly guide. Motor IDs and baud rates are configured before the documented assembly workflow; a matched list of purchased components is only one stage of the work. Motor setup

This is a comparison of source documents and recorded sourcing inputs. We have not assembled, powered or calibrated either configuration, and cannot report its build time or task performance.

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