Custom-built medium-format 3D printer following Wilson II open-source design from RepRap community. Built entirely from sourced components to understand printer mechanics, firmware, and to have a reliable workhorse for medium-sized parts.

Build Motivation: Needed printer for longer parts at smaller scale—bridging gap between desktop printers (small) and Large Prusa (massive but slow).

Source Design: Wilson II plans (RepRap community + YouTube build guides)

Frame & Motion:

• Aluminum & 3D printed frame (Wilson II design)

• Cartesian motion system (X-Y-Z)

• Linear bearings on smooth rods

• GT2 timing belts (X/Y axes)

• Lead screw (Z-axis)

Electronics:

• Controller: RAMPS 1.4 (RepRap Arduino Mega Pololu Shield)

• Microcontroller: Arduino Mega 2560

• Stepper Drivers: A4988

• Firmware: Marlin

• Interface: LCD controller

Hot End & Extruder:

• E3D-style hot end (or clone)

• Bowden or direct-drive extruder (specify which)

• Heated aluminum bed

• Glass print surface

Power:

• 12V power supply

• Heated bed: High-current circuit

• Safety: MOSFETs for bed/hot end control

Why Source vs Kit:

• Cost savings (~30% vs complete kit)

• Component selection flexibility

• Learning supply chain and part specifications

• Understanding every component's purpose

Sourcing Breakdown:

• Frame/hardware: Local hardware store + McMaster-Carr

• Electronics: Amazon/AliExpress (RAMPS boards, Arduino)

• Motion components: Amazon (bearings, belts, pulleys)

• Hot end: E3D clone

• Print bed: Aluminum plate + heating pad

• Miscellaneous: Wiring, connectors, heat shrink

Build Documentation:

• Followed YouTube build series + RepRap wiki + community forums. Assembled over several weekends, troubleshooting along the way.

Learning Curve:

• First experience with RAMPS boards

• Learned Marlin firmware configuration

• Understanding stepper motor wiring/polarity

• PID tuning for temperature control

• Bed leveling techniques

Upgrade: Heated Bed & Power Management

Problem: Original heated bed setup:

• 12V heated bed connected directly to power supply

• High current through RAMPS MOSFET (risky)

• Slow heat-up times

• Potential for MOSFET failure (fire hazard)

Solution: External MOSFET Module:

• Added dedicated high-current MOSFET

• Routed main bed power through external MOSFET

• Control signal from board (low current)

• Main power bypasses the control board

Benefits:

• Safer operation (reduced fire risk)

• Faster heat-up (better power delivery)

• Protected control board

• More reliable long-term operation

This upgrade addressed a common failure point in RAMPS-based printers.

Second Upgrade: Print Head Refinement

Initial Print Head: Basic hot end and extruder setup—functional but not optimized.

Improvements:

• Upgraded to genuine E3D hot end (better temp control, reliability)

• Improved part cooling fan setup

• Better filament path (reduced friction)

• Optimized retraction settings

Goal:

• Finer layer adhesion

• Smaller feature details

• Better overhang performance

• More reliable extrusion

Result: Achieved improved print quality suitable for detailed parts (small mechanical components, fine features).