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Machine-translated by Robotheca from the original in Chinese (opens in a new tab). License: MIT (opens in a new tab).

Atlas Rover Mk.1 V1.0 Assembly Guide

Coordinate System

X-axis: positive forward, negative backward
Y-axis: positive left, negative right
Z-axis: positive upward
Origin: center of the bottom mounting plate

Hierarchy Structure

Base layer: 18650 battery box, motor branch switch, boost module, wiring harness fixation.
Drive layer: four N20 motors, two DRV8833 modules, four 64T gear wheels.
Middle electronic board: PCA9685, wiring distribution, recommended external car lights/RGB.
Front layer: ESP32 dual-eye main control board, fixed with M2 brass standoffs; speaker placed at the rear or bottom of the front.
Brass cage frame: 2.0 mm brass rods as main beams, 1.5 mm brass rods as diagonal supports.

Reference Image Selection

The reference images show the orientation of the brass cage frame, headlights, dual eye guards, top handle, and rear horn mount.

Mk.1 currently uses four N20 physical motors, but the control remains differential steering on the left and right sides, without adding independent speed control for each wheel, TP4056, MAX98357A, or external microphone.

The brass wheel arches and side rails can create the visual stance of a four-wheel vehicle, but all four 64T gear wheels participate in both support and driving.

Brass Material Requirements

Material	Theoretical Usage	Recommended Purchase	Purpose
2.0 mm brass rod	~2.57 m	Recommended to buy 3 m	Main load-bearing frame, bumper, top handle, wheel arches
1.5 mm brass rod	~1.18 m	Recommended to buy 2 m	Eye guards, diagonal braces, lamp brackets, horn trim
0.8-1.0 mm fine copper/brass wire	~0.6 m	Optional to buy 1 m	Weld point binding, decorative wrapping; not for main structure

Brass Cutting List

Material	Part	Quantity	Length per Piece (mm)	Total Length (mm)	Shape	Notes
2.0 mm	Bottom Side Beams	2	120	240	Straight	One on each side; first assemble the bottom 120 x 90 mm rectangular frame
2.0 mm	Bottom Front/Rear Crossbeams	2	90	180	Straight	Overlap-welded with side beams; leave 2-3 mm overlap allowance at corners
2.0 mm	Middle Layer Side Rails	2	112	224	Slightly Outward Curve	Located on the outer side of the electronics layer; avoid USB-C and switches
2.0 mm	Middle Layer Front/Rear Crossbeams	2	86	172	Straight	Outer frame protecting the chassis control board and two DRV8833 modules
2.0 mm	Top Side Beams	2	105	210	Straight	Narrows toward the front; refer to the top cage structure in the diagram
2.0 mm	Top Front/Rear Crossbeams	2	82	164	Straight	Connects the four corner vertical posts at the top
2.0 mm	Four Corner Vertical Posts	4	58	232	Straight	Transitions from bottom frame to middle/top layers; tack-weld first, then correct vertical alignment
2.0 mm	Front A-Pillar Diagonal Braces	2	72	144	Slightly Curved	Extends from the front bumper to both sides of the "dual-eye" plate, forming the front face as shown in the reference diagram
2.0 mm	Rear Vertical Posts / Speaker Guards	2	58	116	Straight	Provides protection for the rear small speakers and wiring harness
2.0 mm	Front Lower Bumper U-Shaped Bar	1	150	150	U-Shaped Bend	Bent around a 18-22 mm cylinder at both ends; installed below the headlights
2.0 mm	Front Light Bar Crossbeam	1	92	92	Straight	Mounts the WS2812B LED strip or ring bracket
2.0 mm	Rear Bumper U-Shaped Bar	1	135	135	U-Shaped Bend	Protects the rear speakers and charging/programming wiring harness
2.0 mm	Top Handle	1	170	170	U-Shaped Bend	Bent around a 30-35 mm cylinder; legs welded to the top crossbeam
2.0 mm	Left & Right Wheel Arch Guards	2	170	340	Large Arc Bend	Bent around a 34-40 mm cylinder; ensures tires do not rub
1.5 mm	Dual-Eye Guard Ring	2	145	290	Circular Ring	Bent around a 42-46 mm cylinder; only protects the outer edge, does not press against the touchscreen
1.5 mm	Guard Ring Connecting Lugs	4	25	100	Short Straight	Connects the guard ring to the small vertical posts on the front; can be fine-tuned later
1.5 mm	Side Diagonal Braces	6	55	330	Diagonal Brace	Refer to the side X/diagonal rod effect in the diagram; symmetrically arranged on both sides
1.5 mm	Wire Routing/Strap Bridge	6	35	210	Short U-Shaped	Provides fixed points for motor wires, light wires, and speaker wires
1.5 mm	Front Light Small Bracket	2	35	70	L-Shaped	Supports the LED strip from behind; insulate between the light board and brass
1.5 mm	Rear Speaker Guard Strips	4	45	180	Straight	Creates the circular speaker grille effect at the rear as shown in the reference diagram

Mechanical Steps

Stage	Task	Method	Acceptance
0	Prepare Base	Print or trace the `AR-MK1-003_BaseTemplate.svg` to draw a 110 × 72 mm base plate and a 120 × 90 mm outer frame on paper. Compare all brass parts against the paper template before cutting.	Centerline, wheel axle lines, and battery position are marked on the base plate.
1	Drill Base Plate	Cut a 110 × 72 mm FR4/acrylic base plate. Drill M2 standoff holes, battery tie-down holes, and four N20 motor mounting holes/slots.	Sand the plate edges so M2 screws slide in smoothly.
2	Install Power Layer	Mount the 18650 battery holder, four N20 motors, four 64T gear wheels, 5 V high-current boost module, and motor branch switch. Do not install the brass cage yet.	Wheels do not scrape the plate, all four wheels touch the table simultaneously, the battery can be removed, and the switch can be toggled from the side.
3	Weld Bottom Brass Frame	Weld a 120 × 90 mm bottom frame from 2.0 mm brass rod. Reinforce the corners by wrapping 0.8–1.0 mm fine copper wire 2–3 turns before tinning.	Frame sits flat on the table without warping; corners are essentially square.
4	Build Mid-Level Protective Frame	Weld the mid-level side rails and front/rear cross beams at approximately Z = 42–48 mm. This layer protects the bottom control board, front and rear DRV8833 modules, and wiring harness.	Leave at least 3 mm clearance above modules; USB-C port remains unobstructed.
5	Install Electronics Mid-Layer	Secure the XIAO ESP32C3 bottom control board, front DRV8833, rear DRV8833, and 5 V high-current boost module to the mid-level plate or base plate. Insert wires first, then tighten screws.	Driver board solder pads do not contact brass; signal wires have slack.
6	Build Front Face & Dual-Eye Bracket	Install the ESP32 Dual-Eye board using M2 standoffs. Then add the front A-pillar, Dual-Eye guard ring, and front light-bar cross member. Weld the guard ring last to avoid pressing on the display.	Dual-Eye board width is 93.5 mm and may protrude slightly; guard ring does not block the touch area.
7	Build Top & Side Cage	Weld the upper side beams, cross beams, top handle, and left/right wheel-arch rails. Use 1.5 mm brass rod for the diagonal braces; keep them symmetrical left-to-right.	Overall vehicle height is kept around 110 mm; wheels can rotate freely.
8	Route & Secure Wiring	Route battery and motor wires along the inside bottom edge; UART and lighting data lines along the mid-level; speaker wires along the inside of the front or rear. Secure every 30–40 mm with heat-shrink tubing or cable ties.	Wiring does not touch tires and is not abraded by brass edges.
9	Power-Up in Stages	First power only the Dual-Eye main controller; then the XIAO bottom control board; then the front and rear DRV8833 modules with wheels still off the ground; finally connect the WS2812B LEDs and speaker.	No overheating, odors, reboots, or abnormal motor jitter occur.

Bending and Welding Methods

First, draw the 120 × 90 mm outer frame on paper, then attach the paper template to a wooden board or cutting mat.
Use flat-nose pliers and a cylindrical tool to bend the 2.0 mm brass rod into a U-shape, starting from the center line and bending symmetrically on both sides.
Wrap the 1.5 mm eyelet around a 42–46 mm cylinder to form a ring, leaving a 3–5 mm overlap at the cut.
The welding sequence is: bottom frame, vertical posts, middle frame, top frame, front panel, and fine diagonal braces. After welding each layer, place it on a flat table to check for flatness.
For stronger joints and a cleaner look, you can first wrap 0.8–1.0 mm fine copper/bronze wire around the joint 2–3 times before tinning or silver soldering.
If using acid-based flux, apply it only to brass structural parts; afterward, clean thoroughly to avoid transferring acid flux to the electronics board.
Whenever possible, complete all brass welding before installing the electronics board. If repairs are needed later, remove the battery and protect nearby wiring harnesses with a damp cloth or heat shield.

Acceptance Inspection

Wheels must rotate freely without touching the brass chassis.
The front eye ring must not press against the dual-eye main control board.
The USB-C port must accept a plug normally for charging and flashing.
The battery must be removable without desoldering.
Motor branch circuits can be powered off independently.
No exposed positive battery wires may contact the brass chassis.

Files by @davidwang960707-gpu, at commit 675d6f2, read from GitHub in your browser. Hardware license: MIT; software license: MIT. Robotheca doesn't review code: read it before running it.