Project Logs

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• Designing and Machining the Components (My First Fusion CAM Project)

  Gary Alose • 06/03/2026 at 21:34 • 0 comments

  This part of the project was a completely new experience for me. I don’t come from an engineering background, and I’m a senior citizen who learned all of this on my own, without formal training in CAD, CAM, machining, electronics, or pneumatics. I’m not saying that to brag — only to emphasize that if I could figure this out, step by step, anyone with patience and curiosity can do it too.

  This controller wasn’t just an electrical project. It required custom brackets, plates, and machined parts that had to fit into the existing machine with precision. That meant learning Fusion 360, learning Fusion CAM, and learning how to run a full‑size CNC — all at the same time.

  It was intimidating at first, but it turned out to be one of the most rewarding parts of the entire build.

  Designing the Parts in Fusion 360

  Before cutting any metal, I modeled every part in Fusion 360. This was my first real exposure to Fusion’s CAD tools, and I quickly learned how powerful it is to be able to visualize the entire assembly before making anything physical.

  Designing for an existing machine is very different from starting with a blank slate. Every bracket, plate, and mount had to fit within the constraints of the machine I was modifying:

  • Existing bolt patterns
  • Limited space inside the enclosure
  • Interference with moving parts
  • Cable routing paths
  • Pneumatic line clearances

  Fusion let me see how each piece interacted with the others. I could rotate the model, check clearances, and make sure everything would fit before committing to metal. That alone saved me from countless mistakes.

  Learning Fusion CAM — A Trial by Fire

  Fusion CAM was a whole new challenge. The simulations are helpful, but they don’t prepare you for the reality of chips flying, cutters chattering, or end mills snapping because the feeds and speeds were wrong.

  Fusion assumes you already know machining fundamentals. I didn’t.

  The default feeds and speeds Fusion generated were far beyond what my machine could handle. So the early stages were a lot of:

  • Trial and error
  • Adjusting toolpaths
  • Slowing down feeds
  • Reducing stepdowns
  • Breaking a few tools
  • Learning what my machine liked

  Eventually, I started to understand how to tune the toolpaths for my specific mill. Adaptive clearing became my friend. 2D contour became my finishing pass. Drilling cycles finally made sense.

  And slowly, the toolpaths started to look — and sound — right.

  Machining the Parts on the CNC

  Once the CAM was dialed in, it was time to make chips.

  This was my first time machining custom parts on a full‑size CNC, and it was both exciting and nerve‑wracking. Parts that required machining on all four sides were especially challenging. Each side needed its own setup, and everything had to reference the same zero point with precision.

  I learned:

  • How to fixture stock securely
  • How to probe and set work offsets
  • How to maintain consistent zero between setups
  • How to avoid tool deflection
  • How to recover from mistakes

  There’s nothing quite like watching a part you designed take shape in real metal. The first time a part came off the machine and matched the Fusion model perfectly, it felt like magic.

  Assembly — The Payoff

  Once the parts were machined, the assembly was surprisingly straightforward. Because the Fusion model had already proven how everything fit together, the real‑world assembly went smoothly.

  • Holes lined up
  • Brackets fit
  • Clearances were correct
  • Nothing interfered
  • Everything bolted up exactly as planned

  Seeing the physical parts match the digital model was incredibly satisfying.

  Sharing Files (Without Releasing Everything)

  I’m not ready to publish the full Fusion files or CAM setups yet, but I do want to share enough to help others understand the process.

  So in this log, I’ll include:

  • Screenshots of the Fusion model
  • Screenshots of the CAM toolpaths
  • Photos of the machined parts
  • Photos of the parts installed on the machine

  This gives readers a clear picture of the build without releasing the full...

  Read more »

• Full Schematic and Deep‑Dive System Operation

  Gary Alose • 06/03/2026 at 21:03 • 0 comments

  This log presents the complete electrical schematic for the controller and explains how the relay logic, spindle enable chain, and pneumatic controls work together to create a safe, reliable hybrid spindle and toolchange system.
  
  By this point, the earlier logs have covered the manual spindle control, Mach4 integration, high‑level architecture, and pneumatic theory. Now we can finally walk through the wiring and logic that make the system behave like an industrial machine.
  
  Before diving into the detailed operation of each section, it’s helpful to see the entire system laid out visually—how the signals flow, how the relays interlock, and how the electrical and pneumatic sides connect. The schematic below serves as the reference point for the explanations that follow.
  

  Schematic Overview

  The schematic is organized into functional blocks:

  • Manual Spindle Control Arduino Nano, AD9833, manual RUN/STOP, manual direction
  • Mach4 Spindle Control PUL/DIR/ENABLE inputs, opto‑isolated interface, mode switch routing
  • Relay Logic Section Mode selection relay Safety gate relay Toolchange relay Capture confirmation relay Master enable relay
  • Pneumatic Solenoid Control Capture solenoid (Stage 1) Main ram solenoid (Stage 2) Limit switch feedback
  • Power Distribution 24VDC logic 110VAC solenoid power E‑Stop chain Slide interlock

  Each block is electrically isolated where appropriate and tied together through the relay logic that enforces safety.

  Relay Logic — The Heart of the System

  The relay network is what makes this controller fundamentally different from typical hobby CNC conversions. Instead of trusting software, the system uses hard‑wired logic to enforce safety and sequencing.

  Here are the key relays and their roles:

  1. Mode Selection Relay

  Selects which spindle control source is active:

  • NC → Manual enable path
  • NO → Mach4 enable path

  Only one can be active at a time. This prevents cross‑feeding signals or simultaneous control.

  2. Safety Gate Relay

  This relay enforces the global safety conditions:

  • E‑Stop must be OK
  • Slide interlock must be OK
  • Toolchange must be inactive

  If any of these conditions fail, the relay drops and the spindle enable line (blue) is forced LOW.

  This is the electrical equivalent of a “master safety AND‑gate.”

  3. Toolchange Relay

  When the Toolchange switch is ON:

  • The spindle enable path is forcibly opened
  • The capture solenoid receives 110VAC
  • The system enters toolchange mode

  This relay ensures that toolchange and spindle motion are mutually exclusive.

  4. Capture Confirmation Relay

  This relay is controlled by the capture bar limit switch.

  • When the capture bar is fully extended and has physically captured the spindle, the switch closes
  • This energizes the relay
  • The relay then allows power to reach the Main Ram solenoid

  This is the mechanical guarantee that the spindle is secured before the main ram actuates.

  5. Master Enable Relay

  This is the final gatekeeper before the spindle drive.

  It receives:

  • The selected enable source (manual or Mach4)
  • The safety‑gated enable path
  • The toolchange lockout

  Only when all conditions are satisfied does this relay close and send the ENABLE signal to the spindle drive.

  Spindle Enable (Blue Line) — Final Logic Path

  The ENABLE signal to the spindle drive is the output of the entire relay chain.

  It can only go HIGH when:

  1. E‑Stop OK
  2. Slide interlock OK
  3. Toolchange inactive
  4. Mode selected (manual or Mach4)
  5. That mode’s enable signal is active
  6. All relays in the chain are energized

  If any condition fails, the blue line drops to LOW instantly.

  This is why the system behaves safely even if:

  • Mach4 crashes
  • The Arduino locks up
  • A wire breaks
  • A relay fails
  • Power flickers

  The default state is always safe.

  Pneumatic Solenoid Control (Electrical Side)

  The schematic shows two 110VAC solenoid outputs:

  Capture Solenoid (Stage 1)

  Powered when:

  • Toolchange switch is ON
  • E‑Stop is OK

  This extends the capture bar.

  Main Ram Solenoid (Stage 2)

  Powered only when:

  • Toolchange switch is ON
  • E‑Stop is...

  Read more »

• Pneumatics, 5‑Way Valve Operation, and the Toolchange Sequence

  Gary Alose • 06/03/2026 at 20:54 • 0 comments

  The pneumatic side of this controller is just as important as the electrical logic. The toolchange system relies on controlled air movement, mechanical confirmation, and staged sequencing to ensure the spindle is safely captured before the main ram actuates. This log explains the pneumatic components, how 2‑position 5‑way valves work, and how the toolchange sequence unfolds from start to finish.

  Understanding 2‑Position, 5‑Way Valves

  Before building this system, I had to learn how industrial pneumatic valves actually work. The toolchange mechanism uses two 2‑position, 5‑way solenoid valves, which are the standard choice for controlling double‑acting cylinders.

  What “2‑Position, 5‑Way” Means

  • 2‑Position The valve has two stable states:
    • De‑energized (default)
    • Energized (solenoid powered)
  • 5‑Way The valve has five ports:
    • P – Pressure (air supply)
    • A – Cylinder port (extend)
    • B – Cylinder port (retract)
    • EA – Exhaust for A
    • EB – Exhaust for B

  How It Works

  In one position, the valve routes air to extend the cylinder and vents the retract side. In the other position, it routes air to retract the cylinder and vents the extend side.

  This gives full control over:

  • Extend
  • Retract
  • Exhaust
  • Holding position

  It’s the same valve style used in industrial ATC systems, pneumatic clamps, and automated machinery.

  Pneumatic Components in This System

  The toolchange mechanism uses two cylinders and two valves:

  1. Capture Bar Cylinder (Stage 1)

  • Controlled by the Capture Solenoid Valve
  • Extends the capture bar toward the spindle
  • Has a limit switch at full extension
  • Must fully extend before the main ram is allowed to fire

  2. Main PDB Ram (Stage 2)

  • Controlled by the Main Ram Solenoid Valve
  • Performs the actual tool release or clamp action
  • Only energizes when the capture bar limit switch is made

  3. Air Supply

  • Regulated shop air
  • Filtered and reduced to the correct pressure
  • Feeds both valves

  4. Limit Switch (Capture Confirmation)

  • Mounted at the end of the capture bar travel
  • Closes only when the spindle is physically captured
  • Electrically gates the Main Ram solenoid

  This switch is the mechanical guarantee that the spindle is locked before the main ram actuates.

  Toolchange Sequence (Pneumatic Operation)

  The toolchange process is a two‑stage, mechanically confirmed sequence. Here’s how it works from the moment the operator flips the Toolchange switch:

  1. Toolchange Switch ON → Capture Solenoid Energizes

  • The controller energizes the Capture Solenoid Valve.
  • The valve shifts to its energized position.
  • Air is routed to the extend side of the capture cylinder.
  • The capture bar begins moving toward the spindle.

  At this point:

  • The spindle is already disabled by the electrical safety chain.
  • Only the capture bar is allowed to move.

  2. Capture Bar Extends and Engages the Spindle

  As the capture bar reaches the spindle:

  • It physically locks onto the spindle/tool holder.
  • When it reaches full extension, it presses the capture limit switch.

  This switch is the critical mechanical confirmation that the spindle is secured.

  3. Limit Switch Closes → Main Ram Solenoid Energizes

  Once the limit switch is made:

  • The controller now allows the Main Ram Solenoid Valve to energize.
  • The valve shifts, routing air to the main PDB ram.
  • The main ram actuates, performing the tool release or clamp action.

  This ensures the main ram cannot fire unless the spindle is physically captured.

  4. Toolchange Switch OFF → System Returns to Safe State

  When the operator turns off the Toolchange switch:

  • Both solenoids de‑energize
  • Both valves return to their default positions
  • Air is routed to retract the cylinders
  • The capture bar and main ram return to their home positions

  The spindle remains disabled until all interlocks are satisfied.

  Pneumatic Safety Behavior

  The pneumatic system is tied directly into the electrical safety chain:

  • E‑Stop drops both solenoids immediately
  • Toolchange Active forces spindle enable LOW
  • Capture limit switch must be made before the main ram can fire
  • Loss of power...

  Read more »

• High‑Level System Overview

  Gary Alose • 06/03/2026 at 20:43 • 0 comments

  1. Hybrid Spindle Control (Manual + Mach4)

  The spindle can be driven from either:

  • Manual mode using an Arduino Nano + AD9833 pulse generator
  • Mach4 CNC mode using standard PUL/DIR/ENABLE signals

  A 5‑pole mode switch and a set of relays ensure that only one source controls the spindle at a time. Regardless of mode, all spindle commands must pass through the same safety chain before the drive is allowed to energize.

  2. Pneumatic Toolchange System

  The machine uses two 2‑position, 5‑way solenoid valves to operate:

  • The Capture Bar (first stage)
  • The Main PDB Ram (second stage)

  The sequence is:

  1. Toolchange switch ON energizes the Capture solenoid.
  2. Capture bar extends toward the spindle.
  3. A mechanical limit switch confirms the bar is fully extended and has captured the spindle.
  4. Only then does the Main Ram solenoid energize to perform the toolchange action.

  This two‑stage, mechanically confirmed sequence is the same approach used in industrial ATC systems.

  3. Hard‑Wired Relay Safety Logic

  The system uses relays—not software—to enforce safety. This means:

  • The spindle cannot run during toolchange.
  • Toolchange cannot proceed unless the spindle is disabled.
  • The main ram cannot fire unless the spindle is physically captured.
  • E‑Stop overrides everything instantly.
  • Slide interlock must be satisfied before spindle enable is allowed.
  • All relays fail to the safe state if power is lost.

  This architecture ensures that even if Mach4 crashes, the Arduino locks up, or a wire comes loose, the machine defaults to a safe condition.

  Safeguards and Safety Philosophy

  This controller was designed around the principle that no software should ever be trusted with safety‑critical decisions. Every dangerous action—spindle enable, toolchange motion, pneumatic actuation—is gated by physical relay logic and mechanical confirmation.

  Key Safeguards

  • E‑Stop Dominance If E‑Stop is pressed, all solenoids drop and spindle enable is forced low.
  • Slide Interlock Prevents spindle enable unless the slide is in the correct position.
  • Toolchange Lockout When Toolchange is active, the spindle is forcibly disabled.
  • Mechanical Confirmation The main ram cannot fire until the capture bar physically hits its limit switch.
  • Mutual Exclusion Spindle motion and toolchange motion cannot occur at the same time.
  • Fail‑Safe Relay Behavior Loss of power → all relays drop → system becomes safe automatically.

  This is the same philosophy used in industrial machinery: hardware enforces safety, software only requests actions.

  What Makes This System Unique

  This controller stands out because it blends hobby‑grade components with industrial‑grade logic:

  1. Manual + CNC Control Without Compromising Safety

  Both control sources coexist, but neither can bypass the safety chain.

  2. Two‑Stage Pneumatic Sequencing

  Capture → Confirm → Main Ram This prevents accidental tool ejection or firing the ram against a spinning spindle.

  3. Mechanical Confirmation Before Dangerous Motion

  The system waits for a physical switch to confirm capture before allowing the main ram to actuate.

  4. Relay‑Based Logic Instead of Software Logic

  No firmware bug or Mach4 glitch can override the interlocks.

  5. Industrial‑Style Mutual Exclusion

  Toolchange disables spindle. Spindle disable is required for toolchange. Both conditions are enforced in hardware.

  
  

  • What Comes Next
    • Log #4 will explain the pneumatic system, including how 2‑position 5‑way valves work and how the toolchange pneumatics operate.
    • Log #5 will present the full schematic and walk through the relay logic, truth tables, and complete system operation.

• Servo Spindle Upgrade and Closed‑Loop Speed Control

  Gary Alose • 06/02/2026 at 22:56 • 0 comments

  Why the Original Spindle Drive Had to Go

  The mill originally came with a small brushless motor rated at:

  • Power: ~1 HP
  • Torque: 2.9 N·m
  • Top Speed: 2500 RPM
  • No encoder feedback
  • No braking
  • No position control

  While fine for manual milling, it struggled badly once CNC features were added:

  • RPM droop under load
  • Slow acceleration and deceleration
  • No way to verify the spindle was stopped
  • No torque control at low speeds
  • No rigid tapping capability
  • No safe interlock for the pneumatic drawbar

  A custom‑machined serpentine pulley was required to increase spindle speed beyond the original motor’s 2500 RPM; with the new servo and 0.75:1 ratio, the spindle now reaches 4000 RPM.

  Once the pneumatic drawbar and capture slide were added, it became obvious: The spindle needed a real servo system.

  ⭐ The New Servo Motor — 110ST‑M06030

  The upgrade uses a 110ST‑M06030 brushless AC servo, a massive leap in capability compared to the original motor.

  Servo Motor Specifications

  • Power: 2.4 HP (1.8 kW)
  • Rated Torque: 7 N·m (continuous)
  • Rated Speed: 3000 RPM
  • Peak Speed: ~4000 RPM
  • Voltage: 220 VAC (±15%)
  • Rated Current: 6.0 A
  • Encoder: 2500‑pulse incremental optical encoder
  • Protection: IP65
  • Weight: ~5 kg

  This is industrial‑grade hardware — not a hobby motor.

  Pulley Ratio and Final Spindle Speed

  To take advantage of the servo’s torque curve, the spindle was re‑pulleyed:

  • New ratio: 0.75 : 1 (motor : spindle)
  • Motor max speed: ~4000 RPM

  Final spindle top speed:

  4000 RPM (motor)×0.75=4000 RPM spindle

  This gives:

  • Higher top speed than the original 2500 RPM
  • Much stronger torque at low and mid RPM
  • Smoother acceleration
  • Better surface finish
  • More consistent chip load

  Mechanical Integration

  The servo mounts to the head using a custom adapter plate and precision‑bored pulley hub. Key mechanical details:

  • Motor shaft aligned to spindle pulley within a few thousandths
  • New serpentine belt pulley machined for the spindle
  • Belt tensioning system upgraded to handle higher torque
  • Encoder wheel mounted directly to the spindle

  This ensures the servo delivers torque smoothly without vibration or belt slip.

  Electrical Integration

  The servo drive is controlled entirely through digital step, direction, and enable TTL‑level signals, just like a CNC axis. This gives Mach4 direct, closed‑loop control of spindle RPM, acceleration, braking, and position without relying on a 0–10 V analog speed command.

  The wiring includes:

  • Step + Direction (TTL) — Mach4 commands exact spindle RPM by outputting a pulse stream, allowing precise speed control across the entire range.
  • Enable Line (TTL) — The motion controller enables or disables the spindle drive, ensuring the servo cannot start unless the machine is in a safe state.
  • Servo Fault Output — Any servo alarm (overcurrent, overspeed, encoder error, etc.) is fed back to Mach4, immediately halting motion and preventing tool‑change activation.
  • Zero‑Speed / In‑Position Signal — Used by the pneumatic drawbar interlock to confirm the spindle is fully stopped before the capture slide engages.
  • Encoder Feedback — The servo’s 2500‑pulse encoder provides accurate RPM reporting and future support for spindle orientation and rigid tapping.

  This allows Mach4 to:

  • Command exact RPM
  • Verify the spindle is stopped before tool changes
  • Monitor servo faults
  • Synchronize future tapping cycles

  The servo’s dynamic braking stops the spindle in a fraction of a second — essential for fast, safe tool changes.

  ⭐ Why a Servo Makes Tool Changes Safe

  The pneumatic drawbar and capture slide require the spindle to be:

  • Fully stopped
  • Not coasting
  • Not drifting
  • Not rotating from belt tension

  A servo spindle solves all of this:

  • It stops instantly
  • It holds position
  • It reports “zero speed” to Mach4
  • It prevents accidental rotation during tool release

  This is a huge safety improvement over the original motor.

  Performance Improvements

  After the upgrade, the spindle now has:

  • Rock‑solid RPM stability
  • Much higher torque...

  Read more »

• R8 Mechanics, Custom Drawbar, and Capture Slide System

  Gary Alose • 06/02/2026 at 22:39 • 0 comments

  On an R8 spindle, the Belleville washer stack provides the spring force that clamps the tool. In the preloaded state, the five nested Belleville pairs pull upward on the drawbar with approximately 540–1,000 lbs of spring force. This upward force pulls the collet into the spindle taper and securely grips the tool shank.

  When the drawbar is pushed downward, the Belleville washers begin to compress and flatten. As the stack compresses, the upward spring force drops, the taper grip breaks, and the collet opens — allowing the tool to be released. To fully release the tool, the washers must be compressed far enough to remove nearly all of the clamping force.

  Because the washers must be flattened to release the collet, the pneumatic cylinder must generate enough downward force to overcome the spring pack. This is why the spindle must be captured before firing the drawbar.

  Belleville Washer Stack Configuration and Load

  The washer stack uses ten disc springs equivalent to McMaster‑Carr 9712K23 (7/16" ID). These washers are rated for:

  • 270 lb at working deflection
  • 495 lb at flat

  The stack is arranged as five nested pairs:    ()()()()()

  Each () is two washers nested in parallel, doubling the load:

  • One pair:
    • Working load ≈ 540 lb
    • Near‑flat load ≈ 990 lb

  Because the five pairs are in series, the load stays the same, but the deflection increases.

  This means the entire stack produces roughly:

  • ~540 lb at normal working compression
  • Up to ~1,000 lb when approaching flat

  This is the clamping force that holds the tool in the spindle.

  ⭐ Washer Force Justification

  The selected Belleville washer stack provides the ideal clamping force for an R8 spindle. With a total preload in the 540–1,000 lb range, this configuration matches the clamping forces used by successful commercial R8 power drawbar systems, which typically target 700–1,000 lb.

  This level of preload is strong enough to prevent tool pull‑out even during aggressive cuts, yet not so high that it overstresses the R8 collet, spindle taper, or drawbar threads. It also preserves a large release margin for the pneumatic cylinder, ensuring reliable tool changes.

  For this machine and spindle size, the current washer stack provides the best balance of holding strength, mechanical safety, and reliable pneumatic release.

  Custom Drawbar Machined From 7/16"-20 Stainless Rod

  To make the Belleville stack work correctly, the drawbar was machined from a length of 7/16"-20 UNF stainless threaded rod and cut to a precise length. Several critical features were required:

  • Correct overall length so the collet seats properly in the R8 taper
  • Collar positioned to meet the spindle “floor” at the exact point needed for proper washer preload
  • Space for the five Belleville pairs to achieve the ~540–1,000 lb upward clamping force
  • A machined top‑hat feature that:
    • Contains the Belleville washer stack
    • Keeps the washers aligned
    • Provides a flat, hardened surface for the pneumatic ram to push against

  Without the correct length and top‑hat geometry, the washer stack would not preload correctly, the clamping force would be inconsistent, and the pneumatic cylinder would not have a reliable surface to act on.

  Cylinder Force vs. Washer Load

  The pneumatic actuator is a CQ2100x12‑3 three‑stage multi‑power cylinder. At 0.7 MPa (101.5 psi) it produces:

  • ~16,493 N
  • ≈ 3,708 lb of force

  Compared to the washer stack:

  • Washer stack max load ≈ 1,000 lb
  • Cylinder force ≈ 3,700 lb

  This gives a 3.7:1 force margin, ensuring:

  • The Belleville stack can be fully flattened
  • The taper grip breaks cleanly
  • The collet releases reliably
  • There is margin for friction, misalignment, and wear

  Even at lower pressures (80–90 psi), the cylinder still exceeds the washer load.

  Why the Spindle Must Be Captured Before Release

  When the cylinder pushes down on the drawbar, the force is transmitted directly through the spindle. If the spindle is not restrained:

  • The spindle will lift upward
  • The Belleville stack will not decompress...

  Read more »

• Introduction

  Gary Alose • 06/02/2026 at 21:49 • 0 comments

  This project documents the custom pneumatic power drawbar I built for my PM‑25MV CNC mill. 

  Most existing designs either block manual Z‑axis movement (captured‑spindle systems) or require a manual capture slide. 

  I wanted something safer, faster, and fully integrated with my CNC spindle upgrade.

  
  

  What Makes This Design Different

  Other pneumatic drawbars fall into two categories:

  • Captured‑spindle systems — safe, but you lose manual Z travel
  • Manual capture‑slide systems — safe, but require two‑hand operation

  My design uses an automatic pneumatic capture slide with an electrical interlock. The drawbar can only fire when:

  • The spindle power is OFF
  • The capture slide is fully engaged
  • The interlock switch is closed
  • A single momentary button is pressed

  This keeps the spindle safe without disabling manual Z movement.

  
  

  Built to Integrate With My Spindle Upgrade

  This drawbar was designed alongside a major spindle upgrade:

  • 220 VAC 1.8 kW (2.4 HP) servo motor
  • AASD servo controller
  • Custom pulse generator for manual mode
  • Mach4 CNC spindle control
  • New pulley machined for a 1 : 0.75 ratio
  • Increased spindle speed from 2500 → 4000 RPM

  What’s Coming Next

  • Photos of the assembly
  • Pneumatic layout
  • Safety interlock wiring
  • Belleville stack details
  • CAD and machining notes

  📜 LICENSE — CC BY‑NC 4.0

  This project is licensed under the Creative Commons Attribution–NonCommercial 4.0 International License. Commercial use is prohibited. Full license text: https://creativecommons.org/licenses/by-nc/4.0/ (creativecommons.org in Bing)

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