Sawppy the Rover open-source 10-DoF rover, 3D render from curio.urdf.xacro

Sawppy the Rover

Rocker-bogie Mars rover model built from 3D prints, 15 mm extrusion and 10 bus servos.

Start the build

What it is

Sawppy the Rover is Roger Cheng's motorized model of the Mars rovers Curiosity and Perseverance, reproducing their six-wheel rocker-bogie suspension. It was inspired by JPL's Open Source Rover and cuts cost by swapping gearmotors, RoboClaw controllers and Actobotics parts for ten LewanSoul LX-16A serial bus servos and 3D-printed connectors on Misumi HFS3 15 mm aluminium extrusion. The repository documents Sawppy V1: STL exports of all 23 printed parts (the editable CAD is a public Onshape document, not a STEP file in the repo), markdown print and assembly guides, a purchased-parts list, a schematic image and a WireViz wiring harness. Control options are the SGVHAK-derived web teleoperation (separate repo), an Arduino Nano wired-joystick sketch in the repo, and community ROS and ROS 2 stacks; the ESP32 code in the repo targets Micro Sawppy, not V1. The repo LICENSE is MIT, and upstream states that the design and build instructions are shared under MIT. The $500 figure is the author's rough US parts budget for a basic rolling chassis, not a priced BOM, and the README describes Micro Sawppy and a future Sawppy V2 as work in progress on the author's blog. The 3D view is converted from the community Curio ROS model (srmainwaring/curio), whose meshes come from the Sawppy CAD, not from this repository.

Licenses

Hardware
MIT
Software
MIT
Docs
MIT

Degrees of freedom

10 DoF driveWheels 6cornerSteering 4

Breakdown source

Rocker-bogieRoversource

Auto-assembled, not yet reviewed

Source record

Sources
511 stars, last push 2025-09-21
HW license
MIT
Cost
$500estimate, basic rolling chassis in parts: Raspberry Pi 3, 10 LX-16A servos, bus board, battery, filament, extrusions, shafts, bearings and hardware; rough US price guideline, upstream says bargain hunters may get closer to 400 USD
Lifecycle
Maintained
Engine
v3.1.1
Checked
Model
curio.urdf.xacro@baec5d6rendered 2026-10-02

Maintain Sawppy the Rover? Claim this page to correct it.

Parts and cost

12 rows

Cost to build

$500USDestimate
  • basic rolling chassis in parts: Raspberry Pi 3, 10 LX-16A servos, bus board, battery, filament, extrusions, shafts, bearings and hardware; rough US price guideline, upstream says bargain hunters may get closer to 400 USD$500estimate

In the source currency, as read on 2026-09-30. Not converted, and not checked against current vendor prices: none of these is a Motari-verified checkout total.

Sawppy the Rover parts, as the source lists them. Prices are the source's, not checked against vendors.

Sawppy the Rover bill of materials
PartQtySpecSourceConfidence
Raspberry Pi 3Budget line includes microSD card, case and a 5V regulator that powers the Pi from the rover battery
1Raspberry Pi 3 with microSD card, case and 5V regulator
vendor not named$50 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 14
high
LewanSoul LX-16A serial bus servoFour steer the corner wheels and six drive the wheels
10LewanSoul (Hiwonder) LX-16A serial bus servo
LewanSoul / Hiwonder$15 each, $150 total upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 15; docs/Parts List.md line 57
high
LewanSoul USB interface boardAlso called BusLinker or Debug Board; one per rover
1USB to serial bus servo interface board
LewanSoul / Hiwonder$10 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 16
high
Misc. electronicsGrouped as one budget line upstream
1Power switch, volt meter, fuse with holder, wires and connectors
vendor not named$20 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 17
high
Battery packUpstream says it allows several hours of operation
15200mAh 2S LiPo battery pack
vendor not named$25 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 18
high
3D printing filamentAbout 3 kg prints all parts; the 23 printed part types and quantities are listed in docs/Parts List.md
31 kg spools
vendor not named$25 each, $75 total upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 19; docs/Parts List.md line 6
high
Aluminum extrusion beamsUpstream notes any 15 mm square beam should work; builders have used MakerBeamXL
17Misumi HFS3 15 mm square: 4 x 385, 4 x 245, 1 x 238, 2 x 182, 2 x 161, 2 x 122, 2 x 117 mm
Misumi cutting service$45 upstream budget figure for cut beamsRoger-random/Sawppy_Rover docs/Price breakdown.md line 20; docs/Parts List.md lines 75-83
high
8mm shaftsDifferential shaft should be steel; the others can be aluminum or steel
158 mm rod cut to 1 x 300, 6 x 50, 4 x 61, 2 x 66.5, 2 x 84 mm
vendor not named$10 upstream budget figure for steel rod stockRoger-random/Sawppy_Rover docs/Price breakdown.md line 21; docs/Parts List.md lines 35-49
high
608 bearingsCommodity skateboard-type bearings are fine per upstream
30608 ball bearing
vendor not named$20 upstream budget figure for the setRoger-random/Sawppy_Rover docs/Price breakdown.md line 22; docs/Parts List.md line 58
high
TurnbucklesLink both rocker-bogie sides to the differential
2Eyes fit M3 fasteners, roughly 5 to 7.5 cm between endpoints; Hobbypark 16617 shown
vendor not named$10 upstream budget figure for the pairRoger-random/Sawppy_Rover docs/Price breakdown.md line 23; docs/Parts List.md line 66
high
Misc. hardwareGrouped as one budget line upstream; docs/Parts List.md itemizes the fasteners
1300 M3x8 socket head screws, 28 M3x16, 300 M3 washers, 300 M3 nuts, 100 M3 heat-set inserts, 100 5/16 in E-clips, 22 M3x8 set screws, 40 #2 1/4 in brass screws
vendor not named$75 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 24; docs/Parts List.md lines 59-65 and 67
high
Laser cut acrylic for equipment bay
1Laser cut acrylic panel
vendor not named$10 upstream budget figureRoger-random/Sawppy_Rover docs/Price breakdown.md line 25
high

Rows from the source's own parts list 46

docs/Parts List.md@16eccd0markdown

Source rowQtyPrice and vendorLine
Clip2n125
88
vendor not listedno price listed
L10
Clip3n20
12
vendor not listedno price listed
L11
Wheel Hub
6
vendor not listedno price listed
L12
LX-16A - Coupler
10
vendor not listedno price listed
L13
LX-16A - Bracket
10
vendor not listedno price listed
L14
Wheel
6
vendor not listedno price listed
L15
Steering Knuckle
4
vendor not listedno price listed
L16
Body Corner
4
vendor not listedno price listed
L17

38 more rows in docs/Parts List.md

How to build

6 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 rover parts

    Print the 23 part types listed in docs/Parts List.md from the STL/ folder (about 3 kg of filament). Upstream prototypes used a 0.4 mm nozzle, 0.3 mm layers, 3 perimeters, 4 top/bottom layers and 30% triangular infill with no supports, first in PLA and then in PETG. Post-process by removing bridge layers, reaming 8 mm holes, tapping or fitting M3 heat-set inserts, and pressing in 608 bearings.

    Motari summarygithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...

  2. Prepare extrusions and shafts

    Get 17 lengths of 15 mm HFS3 aluminium extrusion (cut to length by Misumi or cut yourself). Make the 8 mm shafts: six wheel axle and four steering shafts with retaining clip grooves and set screw detents, two bogie and two rocker pivot shafts with grooves but no detents, and one 300 mm steel differential shaft that needs no grooves.

    Motari summarygithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...

  3. Build the servo actuator and drive modules

    Give each of the ten LX-16A servos a unique bus ID and test it, centre the four steering servos, then fit the printed coupler and bracket. Build four steerable drive modules on steering knuckles and two fixed middle-wheel modules, holding shafts with E-clips and set screws.

    Motari summarygithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...

  4. Assemble the body and suspension

    Fit the corner, bogie and rocker pivot joints, bolt the body box from printed corners and extrusions using the printed M3 nut installation tools, add the differential, then build each bogie and rocker. Mount the rocker-bogie on the body and link it to the differential with turnbuckles; watch the left/right Bogie-Wheel errata.

    Motari summarygithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...

  5. Wire power and servos

    A bare-bones build uses a 2-cell LiPo, power switch, 10A fuse, volt meter and 5V regulator feeding a Raspberry Pi 3, which connects by USB cable to the serial bus translator board; all ten serial bus servos connect in parallel to that board.

    Upstream stepgithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...

  6. Install control software

    Rename servo IDs, then run the SGVHAK-derived web teleoperation on the Pi, or use the Arduino Nano wired-joystick sketch, or one of the community ROS and ROS 2 stacks linked from the README.

    Motari summarygithub.com/Roger-random/Sawppy_Rover/blob/16eccd0e2cf71d2c72...
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.

How reproducible

How confidently this design builds into a working robot, from what its sources publish: each criterion's points, quality tier and evidence.

80/100Strong source coverage, unverified

Engine v3.1.1 at 16eccd0, 2 items reviewed by hand

How this score is computed

Files and sim

14 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.

Simulation

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

The 3D specimen on this page is converted from curio_description/urdf/curio.urdf.xacro at baec5d6.

Builds

0 reviewed

No reviewed builds of Sawppy the Rover 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

Where the facts come from

Last push to Roger-random/Sawppy_Rover: 2025-09-21 (checked 2026-10-02)

Related links

How this page was made

Assembled from public sources on 2026-09-30, 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: 2026-09-30 Roger-random/Sawppy_Rover@16eccd0 README, LICENSE, tree.

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 Sawppy the Rover? 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
[![Motari reproducibility score for Sawppy the Rover](https://motari.io/api/v1/badge/sawppy)](https://motari.io/r/sawppy)
HTML
<a href="https://motari.io/r/sawppy"><img src="https://motari.io/api/v1/badge/sawppy" alt="Motari reproducibility score for Sawppy the Rover" height="20"></a>

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