OpenScout

Choose a chassis before pricing it

The build uses 20 × 20 mm aluminum extrusions in 200 mm and 300 mm lengths, acrylic panels and a revolute hinge. Its instructions list four 90:1, 12 V geared motors with encoders, 112 mm wheels and their adapters. The complete parts list depends on that configuration; changing the frame or drive components changes the build rather than merely changing its appearance. [S001] [S005]

Upstream's $350 headline and 15 kg payload figure are project claims, not a current quotation or a load test performed for this profile. The detailed parts list still leaves some fastener information and wire or breadboard quantities unspecified. A delivered budget needs those gaps resolved, as well as current prices, fabrication and shipping. [S001] [S005]

STEP assemblies, DXF panel files and an illustrated assembly manual are present in the preserved archive. This establishes available design artifacts, not verified dimensions, successful machining or fit. The selected hardware guide is the starting point for assembling a configuration-specific checklist. [S004] [S005] [S012]

Match the wiring to the controller

The electronics route uses an Arduino Mega, two L298N motor drivers, a radio receiver, a 12 V lead-acid battery, a 10 A circuit breaker and a buck converter. The overview calls for the Mega because the encoders and receiver need enough interrupt inputs. The wiring guide gives motor lead colors, receiver channel pins and separate front and rear driver connections. [S001] [S006]

The upload guide points to Software/simple_pid.ino in Arduino IDE. That sketch samples encoder counts and uses a per-motor PID controller to drive the wheels. Its geometry, encoder-count conversion and receiver pulse limits are fixed values in source, so alternate motors or a resized frame require checking those values before assuming equivalent behavior. No firmware upload or radio-control test was performed here. [S008] [S009]

Reconcile the PID instructions with the sketch

The tuning guide describes comparing target and actual motor speed in the Arduino serial plotter and adjusting proportional, integral and derivative gains. It reports a derivative gain of 1 for the authors' implementation. The active sketch instead defines DGAIN as 0.015 and passes that value into each motor controller during setup. The constructor's default derivative value of 1 is overwritten there. [S007] [S009]

The sketch also actively prints throttle and steering values, while the target and measured wheel-speed print statements are commented out. Its serial output therefore needs adjustment before it can supply the speed comparison described in the tuning guide. That adjustment was not made or tested here. [S007] [S009]

These are distinct source values, not interchangeable recommended settings. A builder should retain the selected sketch revision, confirm the physical wheel and encoder configuration, and tune against the documented measurements. This review identifies the discrepancy but does not establish which gain works on a particular build. [S007] [S009]

Several licenses need a clearer artifact map

The overview lists GPL v3, CERN-OHL-W and CC BY-SA. The preserved files contain GPL v3, CERN-OHL-W version 2 and CC BY-SA 2.0 texts. The hardware license file is actually named OSH LICENSE, although the README's link targets LICENCE. The source therefore preserves the terms even where that relative link is wrong. [S001] [S003] [S004] [S010] [S011]

The overview does not precisely allocate all three licenses to individual mechanical, electronics and documentation artifacts. Those layers retain an explicit licensing gap in this profile. Purchased components and external tooling also remain separate from the project source. No assembly, electrical, tuning, terrain or payload test is claimed. [S001] [S004] [S005]