Alloy crafts exceptionally engineered products that inspire delight and loyalty in the people who use them. We collaborate with top designers to bring their vision to life by applying creativity, experience, and sound engineering principles to solve difficult problems. Product engineering is what we love to do. And it’s all we do. That means we focus all our hiring, training and investments on being the best product engineering firm we can be.
We worked closely with iBeat and Ammunition in evaluating different component configurations to optimize the user experience and maintain the design vision. A large, full-round, AMOLED display was selected for clarity and to enable a larger touch interface. A machined metal front bezel provided a premium appearance and durability. An injection molded main housing allowed us to cost-effectively insert mold electrical contacts for battery charging and antennas. With both mechanical and electrical engineers under one roof, Alloy was able to meet challenging schedule and size requirements by quickly iterating design changes at the interface between PCB design and enclosure geometry. The electronics were split into two PCBAs to maximize space in the housings – a main PCBA just below the display and a smaller sensor PCBA nested into the curved bottom of the housing with the battery sandwiched in between. We took advantage of the FPC connecting the two boards to mount some of the taller electrical components in a pocket of available space next to the battery and reduce the product’s overall thickness.
Alloy brought in an RF specialist to design the LTE and GPS antennas and simulate the RF performance of the whole system. The trace antennas were designed as FPCs that were insert molded into the compliant wrist straps. The ends of the straps were captured by lugs that were screwed onto the main housing, pressing the respective contacts together to connect the antenna FPCs to the RF paths on the main PCBA. With injection molding capability on site, Alloy was able to rapidly iterate the design to optimize the band for reliability, comfort, and antenna efficiency. Tested RF performance was remarkably close to the simulations and passed FCC certification.
Alloy selected the lowest power microcontroller capable of driving the beautiful AMOLED display and architected the system such that it was powered down the majority of the time. For always on sensor processing, an Ambiq Apollo series microcontroller was selected as its subthreshold region transistor design provided a lot of processing capabilities for the lowest power consumption.
Before squeezing all the electronics into a 42mm diameter watch, Alloy began by designing a non-form-factor prototype of the main PCBA almost 20 times larger. This allowed us to more quickly and effectively evaluate and debug the circuitry and options for different cellular modules, batteries, touch panels, antenna designs and other components. This also provided an early platform for firmware development by iBeat’s in-house team. Alloy similarly developed a business-card sized, wrist-wearable, sensor PCBA that iBeat used to develop algorithms for the optical heart rate sensor. Alloy then reduced the size of both of these PCBAs to fit into the final form factor, connected by a custom designed FPC. Alloy completed the dense, 10 layer HDI PCB layout in-house, working with our RF consultant to optimize the antenna feed paths, PCB materials, and stackup for maximum efficiency and signal strength at both the prototype and production manufacturers.
The housing assembly required several different sealing strategies. The heart rate sensors were directly exposed through a hole in the bottom of the main housing to get as close as possible to the skin and improve performance versus putting them behind a window. Robotically dispensed epoxy was used to seal around those sensors. The user interface button made use of a flexible rubber membrane to allow the button plunger to actuate a switch inside the watch. The display window required precision machined surfaces and special adhesive to bond it to the bezel. The most challenging seal was between the bezel and the main housing since the large display component left only a thin area around the edge to bond. It took a lot of refinement of the surface finishes, bonding materials, and processing to develop a reliable, repeatable seal for production.
The heart-rate sensor requirements were not achievable in any off-the-shelf modules at the time. Alloy designed multiple, quick iterations of prototype PCBAs with various sensor components and adjustable placements for iBeat’s data scientist to perform experiments and determine the optimum solution for the final design.
The fundamental lid concept is novel: rotating the upper ring counter-clockwise lowers the central plug and enables drinking from anywhere around the edge of the lid, removing the need for a specific sipping location. Rotating the ring clockwise raises the central plug, sealing the contents inside. Accomplishing this motion in a constrained space is deceptively complex, as the outwardly simple plastic parts need to maintain their attachment, position and seals while moving. They must also assemble easily and be robust to repeated usage and abuse. Alloy developed a design that utilizes a helical track to generate the relative motion between the upper ring and central plug, along with additional snap and bayonet attachments to keep the parts properly located.
Keeping the main components sealed throughout their range of motion was a central challenge. Alloy developed custom seals that accomplished this, designing a redundant pair of seals for the most critical leak path and accommodating a part tolerance range that the manufacturer could achieve. The seal design also eliminated spray-back from the pressure of a heated liquid inside the bottle and created a level of thermal insulation that was higher than originally specified.
Alloy was able to maintain the clean exterior aesthetic, in keeping with the visual quality of the Purist brand, while enclosing all the mechanical complexity inside the lid.
Given the moving parts’ sealing, life cycle, and temperature range requirements, this lid required testing to prove out long-term performance. Alloy designed a custom cycle tester to do this, incorporating a torque-limited belt drive system to allow a single motor to cycle three lids open and closed at the same time. In addition to the full mechanicals, Alloy included an Arduino with custom software and additional electronic peripherals to provide easy and flexible control of the tester.
Drivers and commercial fleets rely on ChargePoint charging stations throughout the world in climates ranging from searing heat and sun exposure to driving rain and icy cold. Alloy was tasked with ensuring that the external enclosure strategy and detailed part design met the specifications required for extreme conditions. One of the most challenging aspects of this requirement was managing water ingress from driving rain or hosing off, especially considering the extensive venting, large fans, and resulting air flow needed for the cooling systems. Alloy created concepts and prototypes for interlocking joints, seals, drainage, and baffles. We developed detailed test plans, conducted extensive environmental testing onsite, and worked with vendors to select qualified part materials. After our team incorporated test results and vendor feedback into the final design, the charging station ultimately met internal product specifications and passed testing requirements set by external regulatory organizations.
Alloy was tasked with designing a mechanism which allowed a service technician to reliably make all connections to the power modules with one motion. The system also needed to disconnect all high voltage connections upon opening for operator safety. Each individual connection had its own X, Y, Z, and tilt tolerances in addition to the large tolerance between the module and the system. The design accounted for these tolerances with individual part float and centering mechanisms for each connection. After initial prototyping, we studied the system through detailed force-displacement testing of each connection to identify areas that required improvement. By adjusting specific tolerances, staggering the force peaks, and adjusting spring forces, Alloy was able to meet ChargePoint’s specified reliability, regulatory and usability needs.
ChargePoint defined a set of specifications based on potential product failure modes. Alloy helped develop and run an extensive suite of analyses and validation tests to meet those specifications. Part and system design work was coupled with FEA modeling and hand calculations to ensure the subsystems met the required safety factor. Analyses included part abuse loading, high force winds, vandalism, cyclic wear on moving parts, part tolerance, and thermal expansion. To validate this work, we designed and built test fixtures and tested full prototypes of these designs. Changes based on validation testing were incorporated into the final part designs. The final proven design met an extensive set of requirements ensuring product safety and reliability.
Alloy worked with a growing multi-disciplinary ChargePoint team to develop the Express 250. This complex product had tight release timelines and many risks requiring mitigation. We helped ChargePoint with standards and processes to enable high-quality, efficient communication and cross-functional collaboration. We also led an integrated team through multiple overlapping product builds at their onsite manufacturing facility. This work helped us build trusting relationships and enabled ChargePoint to deliver high quality products on tight timelines.
Each product in our portfolio is so much more than the object in the photograph. It’s the culmination of a story that involves building relationships, sharing hopes and dreams, understanding business objectives, ah-ha moments, tough choices, and passion to get everything just right. We look forward to building many more success stories for our clients in the years to come.
Alloy has been involved in bringing all of Beats’ over-ear and on-ear headphones to market. Initially we provided architectural CAD for the manufacturers to detail with our oversight. Over time, we have owned the mechanical design further into the process, providing tool-ready geometry backed up by several rounds of prototyping to ensure a robust design. The result has been faster overall development times, tighter fit and finish, better integration of acoustic and electrical requirements, and increased durability.
Famous musician/producer Dr. Dre, Ammunition Design, and Monster Cable partnered to kick off Dre’s audio product line with headphones destined to disrupt an entire industry. We were initially brought in to refine the factory’s first pass at the layout. But it soon became clear that we needed to rebuild it from the ground up. We developed a unique gimbals architecture, nesting the ear cup pivots inside the iconic tear-drop headband to reduce the overall thickness. Dr. Dre himself insisted on the folding feature, challenging us to integrate the hinges with hidden wiring into the existing headband thickness. We oversaw every mechanical detail and refinement over the 2+ year process, including several trips to overseas factories.
Beats’ next task was to shrink down the Studio architecture into a lighter, passive, lower-cost headphone. We embraced the challenge by slashing the number of parts and eliminating almost all of the screws. We developed a robust plastic headband that no longer required metal reinforcement. We came up with a fun way to slide, hook and snap the parts together for easy assembly. And we introduced cast metal parts for the hinge and trim to improve the fit and finish.
For the professional musician, DJ and recording engineer, Beats Pro combines a larger, more powerful driver in a super robust package. We developed a bomb-proof mechanical design using die cast aluminum hinges, a stainless steel headband, and formed aluminum ear cups, all optimized to maintain a reasonable weight. Two of the key challenges were the detented hinges that allow the user to pivot the ear cups away from their ears and the unique ear cushion design that forms itself around the edges of the ear cup and dual audio jacks.
In collaboration with the renowned DJ, David Guetta, Beats set out to create a lighter, on-ear headphone dedicated to the hardcore DJ. Like Pro, the headphones needed to stand up to serious abuse and offer the rotating ear cups for single ear listening. This time we developed a cool mechanism that combined the sliding for size adjustment and fore-aft rotation of the ear-cup. The plastic headband required extensive analysis and material testing to achieve proper stiffness and durability.
The Executive headphones introduced a more sophisticated appearance and fold-flat design to the family. Previously, we needed to include both vertical and horizontal rotation in the ear-cup to allow it to conform to wearer’s head. This time we put the vertical hinge up in the headband, allowing the ear cups to rotate flat against the collar bone while being worn around the neck or fit into a slim case appreciated by travelers.
Alloy’s primary responsibility on the project was development of the I/O and battery doors. Both doors needed to be as thin as possible, latch securely closed, yet easily open with a button release. Through extensive CAD architecture studies, tolerance studies and prototyping, Alloy helped drive the battery and connector locations in the camera as the door design developed. The battery door is sprung open for ease of access and the I/O door is detachable for accessory compatibility by utilizing a snap-on hinge. Alloy delivered production-ready designs for both doors, which were validated by a mechanically functional prototype of the camera.
One of the key challenges with the ultra-thin doors was fitting a one atmosphere seal within the thickness. Alloy designed both doors with over-molded radial seals that evolved through a series of analysis followed by quick-turn prototypes and then high-fidelity prototype testing. A cycle test fixture was designed and built by Alloy for opening and closing the doors thousands of times and then validating their water resistance.
GoPro returned to Alloy to design a detachable lens cover mechanism that needed to be difficult to detach accidentally yet easy for the user to intentionally remove and replace. Additional constraints were minimal part count and tool-less operation. Alloy’s engineers developed and prototyped multiple concepts for the mechanism, ultimately settling on a simple, easily-tuned design that shipped with the camera. The pull-and-twist-to-remove design uses stainless steel wires to generate a spring force against cam surfaces that orient the rotation of the cover and bias it down against the camera body.
The first work Alloy did on the Drone was in the arm hinge assembly. Focus was initially placed on the hinge architecture where we explored a variety of locking, detent, and friction mechanisms all while balancing ease-of-use with flight dynamics. Detailed design work included creep and wear analyses.
With the hinge design set, Alloy worked with the GoPro team to define, develop and refine an overall arm design which married aerodynamic, EE, ID and manufacturing requirements. Alloy worked closely with GoPro’s aero and ID team to define a low-drag, stiff and aesthetically pleasing arm profile. Alloy explored an array of manufacturing processes and assembly configurations to generate an easily mass produced, high yield design. We utilized comparative structural and resonance FEA to shorten design optimization loops for weight, stiffness and durability. When engineering test samples took flight, GoPro’s team gathered real-world flight results to validate and improve our FEA. With tight communication and a thorough design-analyze-test feedback loop we matured a complex electro-mechanical-aero design in progressively shorter design cycles.
Alloy was responsible for the design and development of the landing gear assembly. We initially focused on the folding mechanism, and explored various methods for deploying and locking the legs in order to achieve both the usability and robustness goals. The leg design required an embedded sensor which had strict positioning requirements with wire routing that passed through the hinge. The assembly also needed to be user replaceable in case of damage.
As the first point of contact with the ground, the landing gear needed to withstand both vertical and horizontal impacts. Alloy optimized the design and material selections for the landing gear assembly via FEA in order to meet these requirements. We also carried out physical testing in order to validate drop and cycle life performance.
Alloy worked in collaboration with GoPro’s gimbal development team on the mechanism for securely attaching the removal camera gimbal to the drone including electrical connections and vibration isolation. The cantilevered position of the camera at the front of the drone provided a challenge for the damped isolation mounting. Through a thorough process of concept development, analysis, modeling, prototyping and testing, the design was able to meet the high standards set for the video image quality, which has been highly regarded.
Launching a complex product like a mass-production consumer drone is no small feat. It requires focused engineering work across an array of disciplines. Schedules must be aligned. Costs must be optimized. Risks must be mitigated. On the mechanical design, Alloy worked with GoPro to tightly integrate our team members and, in concert, drive the mechanical development. We married our processes and standards for mechanical development with GoPro’s own tried and true development approach. This integrated system delivered high-quality concepts, designs and prototypes within tight timelines keeping the overall project on track.
Key Improvements:
The ERA charging case came with a number of its own challenges, including the need for a solid and satisfying over-center mechanism for the rotating connector within a very tight space. We created breadboard prototypes in our shop to give us a first pass torque target for the over center mechanism. 2D CAD sketches at scale enabled us to quickly determine the maximum spring length differential within the available space. We then explored different approaches for the spring, including custom wire-forms that could fit around other required components. In the end, we fit a single extension spring that nailed the desired feel.
The next challenge was figuring out how to assemble that spring in a small space with limited access. We designed a small assembly fixture out of a couple of machined and 3D-printed parts for assembling our prototypes. It allowed us to sequentially secure the first end of the spring, tension the spring, and then secure the second end of the spring. The fixture worked so well, the design was carried over into production nearly verbatim.
Our first collaboration with Jawbone was for their Jawbone II headset. At the point we were engaged, the design was about to be released to tooling. We were able to flag a number of potential issues ahead of time, as well as provide extensive support on the ground in Asia during production refinement and ramp.
The effort involved balancing numerous competing constraints against a tight deadline. One key challenge was the main patterned cosmetic surface of the product, which served as a flexure for two different switches. Tolerance analysis and refinement of location features and assembly processes helped dial in the fit to where both switches passed a high bar for tactile response.
The project started out with exploring a rectangular in-wall speaker with a static acoustic lens. After getting that design pretty far along, the client realized that they needed to go to market with a round ceiling speaker at the same time. However, due to more varied positioning on ceilings, the lens angle on that model would need to be adjustable. That tapped into the client’s dream of making the lens “close” and be visually quiet when off and then elegantly reveal itself when on. So rather than developing two very different lens systems for each speaker, we proposed developing a single motorized lens module that could assemble into either speaker system. This would improve the consistency of the sound, look, and experience of the different models while minimizing duplicated development of the critical component.
We used a custom stepper motor to allow precise positioning and variable speed control. We included a slip clutch to prevent damage from manually over-riding the system. Isolation mounts and motor driver programming were optimized to minimize vibrations from the motor.
One of the typical problems with architectural speakers is how they transmit vibrations directly into the walls, coloring the sound. This was a particular challenge with these high powered speakers with excellent low frequency production. Many architectural speakers have an open back, using the space between studs as their acoustic chamber. That’s simply too uncontrollable. We developed sealed rear enclosures, stiffened with glass fibers and generous ribbing, that pocket into the walls to create a consistent acoustic chamber and minimize air movement in the walls. We then mechanically isolated the front housing and drivers from the rest of the enclosure with rubber and foam mounts to minimize transmission of structural vibrations.
When you have several hundred watts of power inside a sealed enclosure that’s inside an insulated wall, where does the heat go? We already knew we wanted the front housing to be very stiff for acoustic reasons. So we saw the opportunity to make that part an aluminum die-casting and use it as a heat sink as well. We then developed an aluminum sheet-metal structure to mount the electronics and transmit their heat around the drivers and to the front enclosure.
