Home Cinema Projector
The Beginning
I’ve always loved the idea of a true 4K home-theater setup, but the $2,000–$4,000 price tag for commercial projectors was a non-starter. After binge-watching videos on YouTube, I sketched out my own plan: shrink the cost to ≈ US $500 while keeping native 4K resolution and cinema-grade color accuracy. Eight CAD revisions, a few late-night drilling sessions, and one very bright COB LED later, the journey officially began.
Hurdles Along the Way
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Sourcing high-CRI components on a college budget
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Maintaining tight tolerances across eight stacked chassis layers
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Shedding 100 W of LED heat without cooking the LCD panel
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Removing filters off the LCD panel in order for the 100W LED to pass through
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Finding the right fresnel lens to collimate and bend the light onto the LCD
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Staying under budget as aluminum prices spiked mid-build
Each obstacle forced quick redesigns, late-night soldering, and plenty of trial-and-error.
Overcoming these Hurdles
1. Thermal Management
To keep the high-power LED cool, I mounted it on a repurposed CPU heatsink paired with dual 120 mm PWM fans in a zig-zag airflow path. This prevented noticeable temperature buildup during extended use.
2. Machining & Printing Tolerances
Four chassis layers were cut from aluminum via water-jet and drill-press-aligned for rigidity, while the remaining layers were 3D-printed in PETG for quick iteration.
3. Wiring & Controls
I used pre-made silicone-jacketed 20 AWG and 16 AWG wires for LED and fan connections, keeping the wiring straightforward without integrating advanced control logic. Power runs directly from the constant-current LED driver and fan power source.
4. Cost Optimization
I reviewed my part list against what was actually used. Re-using components I already had (like the CPU heatsink and some aluminum layers) and avoiding parts I didn’t end up needing saved a significant amount compared to my initial budget. For example, the original spreadsheet projected over $900, but actual spending was far lower due to skipped purchases and substitutions.
Results
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Native 3840 × 2160 resolution projected 2 m diagonal from just 2.5 m away
Future Steps
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Upgrade to a 150 W LED for brighter daytime viewing
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Add a full enclosure with magnetic dust filters and a smoked-acrylic lens window
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Integrate Raspberry Pi streaming so the projector is truly stand-alone
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Add a GT2 timing-belt lift to drive all the M6 rods together, moving the optics carriage for sharp focusing
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Relay-gate the cooling loop so the fans and LED power up only when the HDMI signal is live
Additional Photos/Videos
