Auto-assembled, not yet reviewed

SmallRobotArm (Skyentific)

Open-source 6-DoF stepper-driven robot arm by Skyentific.

Dormant. No upstream changes for two years or more. It may still build, but parts, firmware and docs may have drifted.

Last push to SkyentificGit/SmallRobotArm: 2019-09-09 (GitHub, checked 2026-10-01).

Repository activity

Reproducibility80/100Strong source coverage, unverifiedCADBOMWIREFWBUILDLICREPHow it is computed
SmallRobotArm (Skyentific) open-source 6-DoF robot arm, 3D render from AxisTot1 v14.step
simplified 3D ยท AxisTot1 v14.step

About SmallRobotArm (Skyentific)

SmallRobotArm is an open-source 6-DoF robotic arm by Skyentific (SkyentificGit), built around stepper motors. The repository ships Fusion 360 CAD and STL files, PDF mechanical and electronics guides with the original parts lists, and Arduino-compatible C++ firmware. The parts lists date from the original build and are split across the PDFs. The 3D view shows the base and axis subassemblies from the Fusion 360 STEP files, not the complete arm. The repository has not been updated since 2019.

Licenses

Hardware
GPL-3.0
Software
GPL-3.0
Docs
Not published

Degrees of freedom

6 DoF arm 6

Breakdown source

Serial armsource

How to build SmallRobotArm (Skyentific)

5 steps

Steps marked Motari summary condense the linked source; follow the source for exact instructions. Upstream step marks a step taken from the linked guide.

  1. Print the parts

    Print the parts listed in STL/FilesToPrint in the listed quantities. Three arm parts are preferably cut from 3 mm and 4 mm carbon fibre sheet but can be printed from stiff plastic.

    Motari summarygithub.com/SkyentificGit/SmallRobotArm/blob/master/SmallRobo...

  2. Assemble mechanics

    Follow the PDF mechanical assembly guide to build the six articulations and fit the steppers.

    Upstream stepgithub.com/SkyentificGit/SmallRobotArm/blob/cc3e181b607b3196...

  3. Wire the electronics

    Wire the controller and stepper drivers per the PDF electronics schematic.

    Upstream stepgithub.com/SkyentificGit/SmallRobotArm/blob/cc3e181b607b3196...

  4. Flash the firmware

    Upload the C++ firmware from the Software folder to the Arduino-compatible controller.

    Motari summarygithub.com/SkyentificGit/SmallRobotArm/blob/master/SmallRobo...

  5. Calibrate and test

    Start the arm from its folded position. The Simple6DoF sketch enables the joints and drives them open loop to the home position where all joints are 0, then runs its motion sequence; there are no homing sensors.

    Motari summarygithub.com/SkyentificGit/SmallRobotArm/blob/master/SmallRobo...
Print timenot published
Assembly timenot published

Wiring, power and firmware are safety-relevant and shown for reference only. Check them against the source before building.

SmallRobotArm (Skyentific) bill of materials

8 rows

Cost to build

The sources do not publish a cost total. The rows below are what they list, without a sum.

SmallRobotArm (Skyentific) parts, as the source lists them. Prices are the source's, not checked against vendors.

SmallRobotArm (Skyentific) bill of materials
PartQtySpecSourceConfidence
Stepper motor set
61x Nema 8 8HS13-0604S, 2x Nema 11 11HS12-0674S, 1x Nema 17 17HS19-0854S, 2x Nema 23 23HS30-2804S1
StepperOnlinehistorical source PDF subtotal 88.00 (currency not stated in the source PDFs)SmallRobotArmMechanicalAssembly.pdf lines 3-7
high
Timing belt set
52x 87T GT2 2mm 6mm, 1x 139T GT2 2mm 6mm, 1x 128T GT2 3mm 9mm, 1x 152T GT2 3mm 9mm
SDP/SIhistorical source PDF subtotal 36.54 (currency not stated in the source PDFs)SmallRobotArmMechanicalAssembly.pdf lines 9-13
high
Pulley set
53x GT2 20T 2mm 5mm bore plus 2x GT2 3mm 20T 6mm bore
E3D Online / SDP-SIhistorical source PDF subtotal 29.53 (currency not stated in the source PDFs)SmallRobotArmMechanicalAssembly.pdf lines 15-17
high
Bearing set
2021x15x4, 16x8x5, 8x3x3, Q6000 ZZ, Q625 ZZ, Q6001 ZZ, TB51102 bearing groups
HobbyKing / Amazon / HPC Europehistorical source PDF subtotal 50.09 (currency not stated in the source PDFs)SmallRobotArmMechanicalAssembly.pdf lines 19-26
high
Carbon-fibre flat parts
62x Axis3part1, 2x Axis2part1, 2x Axis1part2; can alternatively be printed from stiff plastic
FamousHobby / make yourselfhistorical source PDF subtotal 109.80 (currency not stated in the source PDFs)SmallRobotArmMechanicalAssembly.pdf lines 28-32 and CarbonFibre/Parts lines 1-5
high
Stepper controller option set
6Option 1: 3x TMC2130 + 3x TMCM1110; option 2: 3x A4988 + 3x TB6600
Watterott / DigiKey / HobbyKing / Amazonhistorical source PDF: 333.12 Trinamic option or 49.20 lower-cost option (currency not stated in the source PDFs)SmallRobotArmElectronics.pdf lines 3-9
med
Arduino Mega control electronics
1Optional RAMPS board plus Arduino Mega 2560 or Kingduino Mega 2560
HobbyKing / DigiKeyhistorical source PDF: 44.51 Arduino option or 16.61 Kingduino option (currency not stated in the source PDFs)SmallRobotArmElectronics.pdf lines 11-16
med
Connectors, wiring, fasteners and other hardware
1D-sub 25 connector pair, D-sub cable, detailed mechanical fastener set, magnets, dowel pins, tubes, wires, rubber feet
mixed commodity supplierspartially itemized in source PDFs; electronics screws/other parts not pricedSmallRobotArmMechanicalAssembly.pdf lines 34-68; SmallRobotArmElectronics.pdf lines 18-30
med

Rows from the source's own parts list 3

SmallRobotArmMechanicalAssembly.pdfpdf

Source rowQtyPrice and vendorLine
SmallRobotArm mechanical parts list
mechanical BOM groups with listed quantities
Skyentific / mixed suppliershistorical priced rows subtotal about $313.96 before unpriced commodity items
L1

SmallRobotArmElectronics.pdfpdf

Source rowQtyPrice and vendorLine
SmallRobotArm electronics parts list
6 stepper drivers/controllers plus controller board option and connectors
Skyentific / Watterott / DigiKey / HobbyKing / Amazonhistorical electronics options: about $65.81 cheap option with Kingduino/RAMPS or $377.63 Trinamic/Arduino/RAMPS option
L1

CarbonFibre/Parts@cc3e181text

Source rowQtyPrice and vendorLine
carbon fibre flat parts
2 each of Axis1part2, Axis2part1, Axis3part1
self-fabricatedno price listed
L1

SmallRobotArm (Skyentific) source files

12 files

Files stay in the upstream repository under their own licenses; these links open them there. The 3D model on this page is Motari's conversion of the file named under Simulation.

SmallRobotArm (Skyentific) in simulation

Robot description files a simulator or CAD tool can load, linked at the commit they were found.

No URDF, MJCF, SDF, USD or Onshape model has been found in the sources.

The 3D specimen on this page is converted from Fusion360/AxisTot1 v14.step at cc3e181.

Builds of SmallRobotArm (Skyentific)

0 reviewed

No reviewed builds of SmallRobotArm (Skyentific) yet.

A build log records the evidence (photos, a video, your repository), what the build cost, how long it took and what you changed. Each one is checked by Motari (until a maintainer claims this page) before it shows here, and reviewed builds count toward the reproducibility score.

Sources and provenance

Sources

Last push to SkyentificGit/SmallRobotArm: 2019-09-09 (checked 2026-10-01)

Related links

How this page was made

Assembled from public sources on 2026-06-07, not yet reviewed by the maintainer. Each figure links to where it is stated; a value the sources do not state reads "not published". Last source review: official Skyentific PDFs/source 2026-06-07.

Original files stay intact and separately licensed; Motari adds only the summary on this page. Maintainer? Request a correction or removal.

Badge for the README

Maintain SmallRobotArm (Skyentific)? Show its reproducibility score in the project's README. The badge links back to this page and updates with the score.

Badge: reproducibility 80/100

Markdown
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Not fully met yet: bom evidence (partial). The score is read from the project's own sources, so publishing what is missing is what raises it. A score of 90 or more needs a reviewed build. How the score is computed