Diffirient Lounge
The Diffrient Lounge Chair represents Humanscale’s commitment to human-centered design. During my time as a Design Engineer Intern, I worked under a Design Engineer III to support the product through all phases of development.
Beyond daily engineering responsibilities such as part iteration, drawing updates, and cross-functional coordination, I took ownership of several high-impact projects that are highlighted below.
Tapered Bearing Test Jig
The Challenge:
The tapered bearing supporting the Lounge Chair needed to undergo cycle testing. However, the final tooled components were still in production.
The objective was to design and manufacture a jig that accurately replicated real-world loading conditions in parallel with production to decrease delays.
Design Strategy:
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The jig mounted to a 5 star base for compatibility with internal test equipment
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A 400 lb load replicated user + chair forces
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The central post matched the final spindle geometry
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A precision taper replicated the star base interface
Impact
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Three full test cycles completed over three weeks
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Bearing validation before tooling arrival
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Decreased project timeline
Manufacturing
Full ownership from end to end
Key Aspects
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Press-fit bearing race interfaces to mirror final assembly
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Load distribution plate with wooden extension
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Custom removal tool for rapid race extraction during repeated test cycles
Plastic Friction Ring
The Problem:
The tapered bearing allowed the 100+ lb chair to rotate too freely. The existing metal tolerance ring caused squeaking and required extensive break-in before smooth motion.
The goal was to design a plastic friction ring that delivered immediate smoothness, eliminated noise, and maintained long-term durability.
My Approach:
I prototyped multiple materials and geometries in-house, testing materials, interference and rotational feel.
Key Areas:
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Plastic materials
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Cross-section geometries and interference
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Spindle redesign
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Tolerance compensation
Machined prototypes used for UL test builds
The Solution:
Key Aspects
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Wavy profile to absorb tolerance from contact surfaces
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Oil-impregnated plastic for self-lubrication
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Redesigned spindle for larger ring thickness for durability
Design approved for production -> four-cavity injection mold
Impact:
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Eliminated squeaking
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Removed break-in cycles
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Improved user and product feel
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Production-ready tooling release