How to Build a Low Cost 3D Printer From Scrap Electronics

Introduction

3D printing technology allows you to create physical objects from digital files. While commercial 3D printers can be expensive, you can build your own basic 3D printer from scrap electronics and hardware for under $100.

Building your own 3D printer is an enjoyable DIY project that lets you learn about electronics, 3D modeling, and manufacturing. This article will walk you step-by-step through sourcing components, assembling the frame, wiring up the electronics, calibrating the machine, and printing your first models. With some creativity and patience, you'll have your own desktop 3D printing system up and running in no time.

Sourcing Components

The most important parts of a 3D printer are the frame, axes, extruder, and electronics. Here's what you'll need to source for your build:

Frame and Axes

The frame provides the structure to mount the other components. The axes allow motion in the X, Y and Z dimensions. Good options include:

• Wooden Frame: Use scrap wood beams for a simple frame. MDF or plywood boards also work.
• Metal Bars: Scrap aluminum extrusion is perfect for a sturdy frame.
• Threaded Rods: Use 8-10mm threaded rods cut to length for the X and Y axes.
• Smooth Rods: 8-10mm smooth steel rods are needed for smooth linear motion.
• Stepper Motors: NEMA 17 motors from old printers or CNC machines are ideal for driving the axes.

Extruder

The extruder pushes out thermoplastic filament to build up layers. Parts needed:

• Hot End: This melted the filament. Salvage form old printers or purchase cheap online.
• NEMA 17 Motor: To drive the extruder.
• Filament Drive: Use a salvaged part or 3D print your own. Grips and feeds the filament.

Electronics

The electronics control all components and motion. Key components:

• Control Board: An Arduino or Raspberry Pi serves as the main controller.
• Stepper Drivers: Translates signals from controller to drive motors. Repurpose from old equipment or purchase inexpensive online.
• Power Supply: A 12-24V supply capable of at least 15W will run the printer. An old laptop power adapter is perfect.
• Heater Cartridge: Heats up the hot end. Can be pulled from an old 3D printer.
• Solid State Relay: To control power to heater cartridge safely.
• Microswitches: Endstops help home the X, Y and Z axes.

Assembling the Frame

With the components sourced, it's time to assemble the frame:

• Cut the wooden beams, aluminum extrusions or acrylic sheets to the required lengths for the base and uprights using a saw.
• Use bolts, screws or glue to join the frame components together. Try to ensure the frame is square and rigid.
• Insert the 8-10mm smooth rods into the uprights with bearing mounts as guides. Use set screws to hold in place.
• Insert the 8-10mm threaded rods and secure with couplers or collars. These allow vertical movement.
• Mount the stepper motors to drive the X, Y and Z axes via timing belts, gears or directly driving threaded rods.
• The frame assembly provides the core structure and motion system. Make sure alignments are square and motions are smooth.

Adding the Electronics

Now it's time to wire up the electronics for motion control and heating:

• Mount the Arduino or Raspberry Pi controller at the base of the frame. This provides the brains of the printer.
• Connect and configure stepper drivers to translate signals from controller to motors.
• Connect power supply to controller and stepper drivers. Ensure voltages are correct.
• Connect heater cartridge and thermocouple to hot end.
• Wire up solid state relay between heater and controller to allow temperature control.
• Connect endstops/microswitches to stop axes motion at ends.
• Neatly route and strain relief all wiring from controller to motors, hot end and endstops.

With the electronics installed, the printer can now be controlled to move the toolhead and extrude plastic!

Configuring and Calibrating

Some key configuration steps are required to calibrate the printer before printing:

• Install firmware: Firmware translates GCode into motion. Install Marlin or Repetier onto the control board.
• Tune stepper motors: Adjust stepper driver current for optimal torque and minimal heat.
• Calibrate steps/mm: Find the optimal steps/mm for each axis for accurate motion.
• Level build platform: Use paper to get a 0.1mm first layer height across the bed.
• Calibrate flow rate: Adjust extruder steps/mm for the filament to get the right amount of plastic flow.
• Tune temperatures: Set nozzle and bed temperatures for good first layer adhesion.
• Test print: Try printing a benchmark model like a cube to validate everything works.

Getting the calibration right is crucial before starting on your own prints. Take the time to dial in settings and alignment.

Modeling and Printing Objects

Once configured, you're ready to start printing objects! Here's a quick overview:

• 3D Model: Design models in CAD or 3D sculpting software. STL format is commonly used.
• Slicing: Software like Cura takes 3D models and 'slices' them into layers to generate printer toolpaths in GCode.
• GCode file: This file contains all motion and extrusion commands for the model. It's saved to an SD card or sent directly to the printer.
• Start print: The printer heats up, homes axes, and starts depositing layers according to GCode!
• Finished object: Models are built up from thin layers of plastic. Parts can have complex geometry and custom designs!

With your DIY printer up and running, let your creativity run wild to design and fabricate your own parts and gadgets. Have fun printing!

Improving Print Quality

Here are some tips for troubleshooting and improving the quality of your printed parts:

• Slow print speed: Faster printing can cause inaccuracies. 30-60mm/s is a good range for quality.
• Cool parts with a fan: Adds cooling to help plastic harden and maintain print geometry.
• Verify filament diameter: Make sure your slicer matches your actual filament diameter.
• Clean/level build surface: Get bed leveled and free of oil/dust for filament to stick properly.
• Adjust extruder tension: Calibrate the right grip force on filament to prevent slipping.
• Tune temperature: Adjust nozzle and bed temp to improve first layer adhesion.
• Upgrade firmware: Newer Marlin or Repetier firmware can enhance print quality.
• Stabilize frame: Add braces or triangulate frame to reduce vibration and resonance.
• Enclose printer: An enclosure helps maintain stable temperature.
• Validate XYZ steps: Double check steps/mm for each axis are properly calibrated.

Don't be afraid to experiment with settings and hardware tweaks. Desktop 3D printing is a constant learning process!

Conclusion

Building your own 3D printer from scrap parts is an incredibly fun and rewarding maker project. By understanding key components and how to source, assemble, configure, and operate the printer, you can fabricate your own low cost 3D printing setup. Let your creativity run wild to design imaginative models and bring your ideas to life! With some persistence and ingenuity, you'll be producing great printed parts in no time. Happy printing!