The Actobotics kit from ServoCity ( is a fixed-pitch, channel-based building system using imperial units. Its 1.5” c-channel and ball-bearing based motion system allows teams to iterate and build mechanisms entirely from kit parts.

Special Considerations#

  • Actobotics’ channel hole pattern has many more mounting holes than a Tetrix channel, so it offers more flexibility in terms of mounting.

  • Actobotics uses imperial units across the board, allowing for clean spacing and fitting. However, most other kits use metric.

  • Actobotics can interface with other kits such as REV through a variety of Pattern Adapters.

  • ServoCity offers a 25% off discount for all FIRST® teams making, pricing competitive:

Notable Components#

  • Mini-channel is offered in addition to the standard size channel for non-structural components.

  • Actobotics’ X-rail extrusion system offers immense adjustability and flexibility as it adds a extrusion component to a channel-based kit.

  • To complement the structural offerings, Actobotics uses a series of clamping hubs and a robust 1/4” steel D-shaft.

  • The Linear Motion Kit uses X-rail extrusion to build extending mechanisms.

  • The Servoblocks, which prolongs the life of a servo, are recommended for all teams, regardless of kit. However, Servoblocks seamlessly interface with the Actobotics ecosystem.

  • Actobotics furthermore offers motion options such as bevel gears and Linear Actuator kits (using lead screws) for specific use cases.


Actobotics is a solid choice for new teams, offering a reliable base kit with many options to expand upon.

Kit of Parts#


  • Actobotics provides a great value fixed pitch build system that is generally easier to assemble than extrusion-based systems which require cutting extrusion to length.

  • Actobotics has the patented Servoblocks, which help drastically increase servo life by protecting it from shock loads. More information may be found in the glossary.

  • Actobotics is easily compatible with other build systems such as REV’s kit using adapters which can be found on the Servocity website.

  • Actobotics is more sturdy than TETRIX in terms of drivetrain flex and has more support options to prevent structural bending.

  • The clamping hubs offered are more reliable than set screws, as clamping engages the shaft in more places than a set screw (one face). As discussed in the TETRIX section, set screws in particular are vulnerable to loosening, especially without application of Loctite.

  • Actobotics’ motion system is very robust and relies on ball bearings, which have a lower coefficient of friction than bushings. Actobotics is compatible with the 5mm hex used by REV with their adaptable hubs.

  • Actobotics also allows for face mounting of motors as opposed to clamp mounting.


  • Actobotics is not very cheap, so its cost may be prohibitive for some teams with a low budget. Note that with the 25% off FTC team discount, Actobotics can be cheaper than TETRIX. The only cheaper build system is REV.

  • The XL belts from ServoCity are not great. It is recommended that belts are purchased from ServoCity instead, which may necessitate the use of 3d printed pulleys. There also isn’t a large amount of space inside the channel for a belt or chain run, vastly limiting the size of the pulleys.

  • Channel takes up more space than extrusion, so mechanisms can be a bit larger with the Actobotics kit. To remediate this issue, ServoCity sells mini-channel which is a similar size as extrusion.

8644 Brainstormers' Relic Recovery robot

An example of a successful Actobotics based robot, 8644 Brainstormers: 2018 Winning Alliance Captain (Detroit), Relic Recovery#

9971 LanBros' Rover Ruckus robot

Another successful Actobotics based robot, 9971 LanBros: 2019 Winning Alliance Captain (Detroit), Rover Ruckus#

9794 Wizards.exe's Rover Ruckus robot

9794 Wizards.exe used both Actobotics and REV extrusion to build their Rover Ruckus robot#