Hardware Builder · NPI Engineer · Irvine, CA

Kai-Hung
Chuang

Builder Who Closes the Gap

A decade of independent execution owning the gap between new designs and first working hardware. Self-funded from day one — every prototype had real consequences, every production decision had to justify itself against cost and time. Business Administration degree grounding engineering decisions in economic reality. Hands-on across CNC machining, composites, welding, additive manufacturing, and electronics integration.

7Days to functional prototype
14Days to production approval
$0New tooling or CapEx
$600KContribution margin added
24,000Units shipped on schedule
Hunter Douglas $6M Rescue — Final production window cling with four honeycomb swatch columns fully expanded, zero-CapEx solution shipped 24,000 units on schedule

$6M launch. 60 days out.
Client design failed. No CAD. No budget.

Hunter Douglas's halo product was 60 days from a nationwide retail launch. 24,000 books mid-production. The accessory they'd developed for two years failed validation at the final hour with no native CAD and no specs provided. The Business Administration degree kept the solution grounded in economic reality. The engineering background built it. Both were required to ship.

Full documentation: every prototype stage, the 20+ failed concepts, the parking lot breakthrough, the 20-minute proof-of-concept, and the path from physics validation to 24,000 production units.

Core Projects

Portfolio — CNC mill — aluminum bracket machining in progress
01Machining · Automation · First Principles
The Mill Trilogy

Three X2 mini mills. Learned manual milling on the first. Built a super mill with DRO from digital calipers, ball screws, and a car window motor power feed. Then machined every bracket for the CNC conversion on the machine I built. The tooling built the tooling.

CNC ConversionManual MachiningGeckodriveDRO BuildSolidWorks
Portfolio — Printhead assembly or billet aluminum fixture
02Product Development · NPI · Production Scale
LulzBot Printhead — 2,000+ Units

Ground-up redesign of a deployed industrial platform. Custom billet fixture to machine hobbed drive gears. Scaled to 2,000+ units across three SKUs. Out-competed the OEM's own subsequent release in the aftermarket.

Iterative DesignBillet FixturingDFMBOM Management
Portfolio — S2000 fender flaring or CF trunk on car
03Fabrication · Composites · Full Stack
S2000 Fabrication Program

Metal shaping, 9-part mold making, vacuum-bagged carbon fiber, backyard paint booth. Every part built because the commercial option was too expensive, too ugly, or didn't exist.

Metal ShapingCF LayupMold DesignPaint
Portfolio — Custom upper control arm or SolidWorks geometry model
04Mechanical Engineering · First Principles
Suspension Geometry Correction

Lifted the Tacoma. Lost steering return. Modeled factory suspension in SolidWorks, calculated the correction delta, turned new ball joint couplings on the lathe, milled pockets into factory arms. Factory spec on first alignment attempt.

SolidWorksLatheMIG WeldingSuspension
Portfolio — FPV goggle system internals or assembled unit
05FPV · Airframe Design · Systems Integration
FPV Platforms + Goggle System

Five airframe iterations across full build-fly-evaluate cycles. Complete custom goggle system built from component level when commercial options failed requirements. Full stack owned: operator interface through airframe.

Airframe DesignPCB ReworkFlight TestLCD Integration
Portfolio — Voron build — wire routing detail or full machine
06Machine Design · Open Source
Voron Architecture Contribution

Proposed rotating the flying gantry 180°. The Voron team incorporated it. Every Voron built since uses the layout I suggested. Reverse-engineered their entire STL library to parametric CAD to implement my own improvements.

CoreXYOpen SourceWire RoutingSolidWorks
Portfolio — Installed nav unit — finished result in dash
07Systems Integration · Electronics
Vehicle-Integrated Compute — 3 Generations

Three cars, three packaging constraints. Body filler bezels to CAD-designed enclosures. Custom firmware, relocated hardware, context-aware automation, NFC data transfer. Each generation solved what the previous couldn't.

PackagingCustom FirmwarePCB ReworkThermal Mgmt
Portfolio — Nozzle cam installed — live view output or optics detail
08Sensor Packaging · Optics · Thermal Management
Nozzle Camera System

Miniature sensor payload operating at 250°C proximity in continuous kinematic motion. Hacked endoscope optics repositioned for thermal isolation. Redesigned SMD LED illumination. Community-adopted standard. Later commercialized by others.

OpticsThermal MgmtMiniaturizationSMD Electronics

Build Depth

Not every build needs a full page. Click any item to open the full engineering record.

Portfolio — Racing cockpit — completed build
Racing Cockpit + 20K Units
Designed the cockpit. Community validated demand. Scaled accessories to 20,000+ units worldwide via outsourced supply chain.
MIG WeldingVendor MgmtCommercial Scale
+ Open engineering record
Portfolio — Amuse bumper — mold parting lines
Amuse Bumper, 5-Part Mold
Repaired a damaged $2K Japanese tuner bumper. Analyzed draft angles to reduce planned 9-part mold to 5 parts, then pulled clean on the first demold.
Mold DesignFiberglassPattern Making
+ Open engineering record
Portfolio — PVC vacuum chamber — finished
Vacuum Chamber, $20
Scrap PVC turned on the lathe. Degassing chamber for $20. Later repurposed as a pressurized oil transfer pump.
LatheConstraint SolvingTool Building
+ Open engineering record
Portfolio — Custom leaf pack — painted and assembled
Tacoma Leaf Spring Pack
Two custom packs from $50 salvage springs bracketing spring rate uncertainty. Free lift. Sold the spare.
Spring Rate CalcSuspensionFabrication
+ Open engineering record
Portfolio — Sheldon lathe — restored and repainted
Sheldon Lathe Restoration
Complete teardown, gear restoration, precision alignment, repaint. Functional before. Precise after.
RestorationAlignmentMechanical
+ Open engineering record
Portfolio — CF trunk — finished on car
Carbon Fiber Trunk, 1.77 lb
Two-part mold from OEM plug, full carbon layup, no fiberglass sandwich. 1.77 lb finished weight.
Carbon FiberMold MakingWelding
+ Open engineering record
Portfolio — DDR dance pad — completed build
Arcade DDR Dance Pad
Picked up three non-working commercial pads from two brands. Fixed them, tried both, disappointed in both. Built a better one from scrap wood and a salvaged PCB instead.
Sheet MetalPCB IntegrationScrap Build
+ Open engineering record
Portfolio — Headphone amp — point-to-point wiring
Headphone Amplifiers
cMoy, PIMETA, tube amp, point-to-point with extreme wire routing discipline. Where the Voron wiring aesthetic originated.
Point-to-PointAnalog ElectronicsSoldering
+ Open engineering record