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From a blank screen.
To a working robot.

Two complete builds show every component addition, wire and program from a zero-part workbench. Male narration, on-screen text, captions and exact saved projects are included. Idle gaps are trimmed and playback is paced to the explanation. Three earlier project tours remain below.

Projects are saved as portable JSON files. Your current workbench state stays in this browser; these videos do not imply cloud project storage.

4:18 / MALE NARRATION / ENGLISH CAPTIONS

Build an ESP32 emoji robot from a blank workbench

COMPLETE BUILD FROM ZERO PARTS

A complete zero-part build: enclosure, power, ESP32, servo, face, all eleven wires, controller code and a real runtime recording.

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Read the complete transcript and chapter guide

01 · Start with zero parts

This is a complete Spark build, beginning with an empty BotSims workbench. We add every component individually, connect every wire, write the controller and run it. The recording keeps all build operations, with pauses trimmed and playback paced for this explanation. No robot preset or assembled module is imported.

02 · Find the parts

Open Components to browse the library. Search narrows the list, and the model badges distinguish behavioral components from geometry. Spark needs an enclosure, a two cell battery, a five volt regulator, an ESP32, a servo and an OLED face. We will use the supported virtual interfaces.

03 · Add the enclosure

Search for Emoji enclosure and press Add. This is the first component in an otherwise empty scene. New loose parts start on the ground. Inspector shows dimensions, mass, position and physical attachment. The yellow enclosure will support this small tabletop companion.

04 · Mount battery and regulator

Anchor the enclosure to the world for a stationary desktop demonstration. Choose On Emoji enclosure in the new component placement selector. Add the battery and regulator separately. Use Inspector position fields, in metres, to arrange them. A physical mount makes parts move together; it never creates an electrical connection.

05 · Install ESP32, servo and face

Add the ESP32 DevKit, position servo and OLED display one at a time. Set their positions using the same Inspector fields. Attach the display to the servo so its motion can be previewed. The rest of the electronics remain mounted on the enclosure. Fit brings the whole assembly into view.

06 · Switch to precise wiring

Open Wiring. All electrical components already appear because they belong to the project, but none has a complete circuit yet. Canvas supports dragging or clicking pins. For this first build, choose List and expand Connect using pin selectors, which makes exact terminal selection straightforward.

07 · Connect all power and grounds

Connect battery positive to regulator input, and battery ground to regulator ground. Connect the regulator five volt output to the ESP32 supply, servo supply and display supply. Connect each device ground back to battery ground. These eight connections establish the supply rails and a common reference. Do not feed the display directly from the battery.

08 · Add I squared C and servo PWM

Connect ESP32 SDA to display SDA, and SCL to SCL. Connect virtual servo channel one to the servo PWM input. The completed robot now has eleven wires. Canvas shows the finished network, and the wiring status reports no modeled electrical conflicts or unwired parts. Virtual aliases are not verified ESP32 hardware pin assignments.

09 · Write the controller

Open Code and replace the starter program. The step function stops the wheels, checks for brownout, cycles three face expressions and commands the installed servo by its exact part identifier. A sine wave changes the normalized servo target smoothly. Log messages appear only when the expression changes. The source is included in the downloadable project.

10 · Enable motion of attached parts

In the servo Inspector, enable Move attached parts and choose the Y motion axis. This explicit switch previews the mounted face turning with the servo. It is forward kinematics: collision shapes and inertia remain at the reference pose. It does not prove actuator torque, dynamic joint loading or a physically balanced mechanism.

11 · Run the new robot

Hide the side panels to give the robot more room, select Front view and press Run. This is the actual robot that we just assembled and wired. The display changes expressions and its servo turns the face. Physics runs at one hundred twenty steps per simulated second; the isolated JavaScript controller runs twenty times per simulated second.

12 · Save the finished project

Pause and choose Export project. The portable robot JSON contains all six parts, eleven wires, physical attachments, servo preview settings and controller source. Auto save protects the current project in this browser; an exported file lets you restore it later or on another device. Open or download this exact finished build below the video.

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3:36 / MALE NARRATION / ENGLISH CAPTIONS

Build a two-wheel rover from a blank workbench

COMPLETE BUILD FROM ZERO PARTS

Start with nothing and add ten parts, all twelve wires and a drive controller. Watch the finished rover drive, turn and reverse.

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Read the complete transcript and chapter guide

01 · A second empty workbench

Now build a different robot from zero: Trailblazer, a two wheel rover with a passive front caster. The workbench starts with no components and no wires. We add the mechanism, power system and controller individually, then show every connection and the working drive program. No assembled preset is loaded.

02 · Add and raise the chassis

Search Components for Rover chassis and add it. Raise its center to sixty five millimetres using Position Y, entered as zero point zero six five metres. This leaves clearance for the drive wheels and passive caster. Choose On Rover chassis so the following parts can be physically mounted.

03 · Assemble motors and wheels

Add two geared DC motors and name them Left drive motor and Right drive motor. Place them on opposite sides of the chassis and rotate their long axes across the robot. Add two ninety millimetre rubber wheels with their centers forty five millimetres above the ground. Set each physical parent to the chassis; electrical wiring comes later.

04 · Add caster, battery and regulator

Add a ball caster near the front to complete the support arrangement. Add the two cell battery and five volt buck regulator separately, then arrange them on the chassis using Inspector. Every component contributes mass. A rover that looks assembled still needs a valid power circuit and correctly connected motor channels before it can drive.

05 · Install ESP32 and H bridge

Add an ESP32 S3 virtual controller and a dual H bridge. The controller sends low power direction and PWM commands; the driver supplies motor power from the battery. Fit the assembly, then open Wiring. Hide the side panels if you want more diagram space. All six electrical devices appear automatically.

06 · Wire the supply rails

In List view, connect battery positive and ground to the regulator. Connect the regulator output and common ground to the ESP32. Connect battery positive to the H bridge motor supply, and connect driver ground to the same common ground. These six wires keep the logic supply regulated while the driver uses the battery rail.

07 · Connect both motor channels

Connect ESP32 PWM left to driver PWM A, and PWM right to PWM B. Connect A plus and A minus to the left motor terminals. Connect B plus and B minus to the right motor. All twelve connections are now present. Return to Canvas and arrange the diagram to review the complete circuit and its validation status.

08 · Program forward, turn and reverse

Write a step function with a twelve second repeating sequence. Both motors at positive PWM drive forward. Opposite commands turn the rover. Both negative commands reverse it, followed by a brief stop. A brownout or low battery check commands zero. Log each mode transition. This is a timing demonstration, not autonomous obstacle avoidance; this robot has no range sensor.

09 · Watch real drive simulation

Return to Assembly, fit the robot and press Run. The wheels develop traction through ground contact, and the battery solver includes the motor load. Watch the rover drive, turn and reverse while the view follows it. This run uses the exact ten components and twelve wires that were added during the recording, rather than a substitute preset.

10 · Export and reuse the build

Pause and export a robot JSON backup. The saved project contains the completed mechanism, supply circuit, motor channels and controller. Use the Open project button below to inspect this exact build, or download the file before experimenting. For obstacle avoidance, add and wire a supported range sensor, then extend the controller using the documentation.

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2:43 / MALE NARRATION / ENGLISH CAPTIONS

Build, wire and run an inspection rover

A complete tour of Sentinel: assembly groups, named electrical pins, the patrol controller, live telemetry and a portable project backup.

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01 · Open the saved robot

Welcome to BotSims. Let us explore Sentinel, an inspection rover with twenty six parts and fifty two wires. Open this tutorial's saved project using the button below the video. If another project is open, the workbench asks before replacing it. Keep a backup of your own work first. This project is a reusable starting point, and every part remains editable.

02 · Understand the assembly

Start in the three dimensional assembly. Orbit to inspect the chassis, drive wheels, camera mast and sensor placement. Hold the middle mouse button and drag to pan. The assembly tree explains how parts attach. Groups collect related components; enter a group to focus on its members. The inspector shows dimensions, mass and supported parameters. A detailed shape does not mean that every physical effect is modeled.

03 · Follow the wiring

Open Wiring. Electrical components appear automatically with named pins. Follow battery positive into the regulator and motor driver, and trace the common ground. Controller signals connect to the driver's two channels. To create a wire, drag from a pin toward another compatible pin and release on its snap target. Read the connection diagnostics before running. Validation covers the supported interfaces; it is not a complete circuit design certification.

04 · Read the controller

Open Code to inspect the included virtual JavaScript program. Sentinel reads its range sensor, patrols forward, then reverses and turns near an obstacle. It stops when required sensor data or power is unavailable. This code runs in a bounded browser worker. It is a high level teaching interface, not an emulator for Arduino, ESP firmware or arbitrary native code. You can edit the behavior and use the console to inspect its state changes.

05 · Run and inspect evidence

Press Run and return to Assembly. Watch the actual rover move and compare its battery voltage, current and speed in live telemetry. The differential drive model couples supported battery and motor behavior with mass and traction. Pause before editing. Use the panel controls to hide the inspector, telemetry or console when you need more room. The robot should answer an engineering question, such as how a heavier payload affects acceleration, rather than simply look animated.

06 · Save and continue

Finally, pause the simulation and export the project from the file controls. The workbench saves current working state in this browser, while the downloaded robot JSON is your portable backup. Keep that file before switching devices or clearing browser storage. The tutorial page also offers the reviewed project download and a written transcript. Continue with Reach for a moving arm, or Kestrel for a drone packaging and wiring study. Each project explains its own modeling limits.

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2:15 / MALE NARRATION / ENGLISH CAPTIONS

Program a two-joint bench arm

Inspect an anchored arm, trace two servo channels and run a bounded joint sweep with moving links. Includes the saved project and model limitations.

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Read the complete transcript and chapter guide

01 · Open Reach

This is Reach, a saved two joint bench arm project in BotSims. Open the tutorial project and confirm replacement only after saving your current work. The anchored base supports a shoulder, upper arm, elbow, forearm and gripper layout. This walkthrough uses real workbench captures and an editable project you can download.

02 · Inspect the hierarchy

In Assembly, inspect the attachment tree. The upper arm follows the shoulder, and the forearm follows the elbow. That hierarchy determines which links move when a servo target changes. Select a component to read its mass and parameters. Orbit and pan to check clearances. Group isolation helps you concentrate on the mechanism without losing the rest of the project.

03 · Trace servo power and signals

In Wiring, trace the battery into the regulator. Both servos share a supported five volt supply and ground. The controller uses independent named servo channels for shoulder and elbow commands. These channels are virtual aliases. They do not certify a specific board's pin mapping, current capacity or peripheral configuration. Review warnings and verify the real component datasheets before building hardware.

04 · Inspect the program

Open Code. The program commands a small sinusoidal shoulder and elbow sweep and logs approach, reach and return stages. Targets are angles in radians. The program keeps wheel drive at zero and stops issuing arm targets if power is unavailable. Change one amplitude at a time so that the result stays understandable.

05 · Run the joint preview

Press Run and watch the links move in Assembly. This is a kinematic preview: commanded angles change link poses. It does not solve inverse kinematics, dynamic joint torque, moving link collisions, object grasping or a production pick and place cycle. Static load estimates remain tied to the reference pose. Use the preview to study structure and control logic, and use a suitable dynamics tool for those additional questions.

06 · Keep a portable copy

Pause, inspect the final state and export the project. The saved tutorial JSON includes the full assembly, wiring and controller, so you can reopen and revise it later. The documentation provides this video, captions and a transcript. You now have a second kind of robot project with a different and explicitly documented simulation scope.

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2:27 / MALE NARRATION / ENGLISH CAPTIONS

Archive: mapping drone airframe design tour

Earlier layout-only walkthrough, recorded before the flight release. Its no-flight statements describe the archived version. Current drone presets fly using the new generic model; see the Drone flight guide.

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01 · Choose a mission and shape

Meet Kestrel, a mapping drone design study in BotSims. The drone collection also offers a cargo hexacopter, a guarded inspection quad, a coaxial octocopter, an agricultural layout and a winged vertical takeoff concept. Their shapes are different because their packaging questions are different. Open Kestrel's saved project to follow this walkthrough.

02 · Inspect the airframe

Orbit the grounded X frame and inspect the four booms, landing skids, outrunner motor layouts and two blade propellers. The forward camera and raised navigation receiver illustrate sensor placement. Select components to review dimensions and mass. The navigation receiver is a placement part, and the rotor geometry does not generate lift. This simulator does not currently implement flight dynamics.

03 · Isolate a subsystem

The project groups the airframe, propulsion layout and avionics. Enter a group to work on a smaller subsystem, then return to the full robot. Right click a part to inspect available actions, including compatible model replacement where supported. Review retained and dropped wiring whenever you change a model. A visually similar component can have different electrical interfaces.

04 · Trace the ESC topology

Open Wiring. The four cell battery feeds the distribution board. Its positive rail branches to four electronic speed controller layouts and the five volt regulator. Trace ground, the named controller signals and the three phase connections from each speed controller to its motor. The distribution board provides ideal continuity. Speed controller current, motor commutation, thrust and hover endurance are not computed.

05 · Run an honest design preview

The included program deliberately keeps the drone stationary and logs the model scope. It does not pretend that a ground robot drive command can fly an aircraft. You can inspect the supported powered camera and inertial sensor observations while studying component mass and packaging. The design is useful for assembly and wiring planning; it does not prove flight stability, lift margin, navigation accuracy or airworthiness.

06 · Save and compare variants

Export the project to preserve the airframe, wiring, groups and program. Compare it with another drone preset, such as Porter's cargo geometry or Halo's protective ducts. Keep payload assumptions visible, especially for the agricultural tank. Every tutorial includes a downloadable project, male narration, readable captions and a transcript. Use the guide's accuracy chapter to choose the right model for the question you want to answer.

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