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MECHANICAL ENGINEER & PRODUCT DESIGNER
contact: alec@alecmataloni.com
RECENT PROJECTS: CLASSIFIED
BUSBARS - ITAR CONTROLLED
I would love to share my favorite projects with you here from my tenure at Methode Electronics; however, the vast majority of my work with them is regulated by International Traffic in Arms Regulations (ITAR). I'm able to say that the products which I have designed are currently powering mission-critical hardware located on naval vessels, space exploration vehicles, and fighter jets. Through these projects, I have learned how to properly design solid state electronic devices that will last for decades. I work on products held to high standards, which include intricate braze & solder joints, Gold and Silver plating, and the tightest tolerance requirements.
HEXBUG TOYS: CUDDLEBOTS GARDEN GO-AROUND
CUDDLEBOTS GARDEN GO-AROUND
CUDDLEBOTS GARDEN GO-AROUND
During my tenure at HexBug, I was able to work on the popular Cuddlebots line of toddler toys. In this "Merry-Go-Round"-inspired playset, a flower shaped handle sits atop a grassy exterior, hiding an internal planetary gearset which spins each of the smaller flowers when rotated. Each "Merry-Go-Round" flower cup has a stem which is a powered axle, and has a hidden cam follower at its base. This feature follows a barrel cam wave pattern about the central axis of the toy, allowing the cups to rotate while also rising and falling on the cam slope.
This design is manufactured in the thousands of units, so every technique used to fabricate the assembly has to be quick and inexpensive. The green structure of this product is made using injection-molded polystyrene, while the white plastic gears inside are injection-molded POM ( aka acetal), which is chosen for its self-lubricating properties. The flowers atop the assembly are molded from a TPE (thermoplastic elastomer), which adds to the toy's organic aesthetic and enhances play opportunities. It is held together with a combination of snap fits, self tapping screws, and a quick-dry structural adhesive. These construction methods allow for quick assembly by the operator.
This product needs to look smooth and commercial-ready, so ejector pin location marks are located out of sight; for example, either inside the plastic green shell, or under the petals of the TPE flowers. Note the surface finish differences on the assembly: the bumblebee was given a glossy finish, while other surfaces were not. It is a small, molded part of a simple shape, so the cost to polish the mold for this component to a glossy finish is less severe than it would be for a larger injection molded part like the grassy knoll. The grassy knoll was given a matte finish, which can be achieved with a paper polish of the mold surface or a bead blast. The molds themselves were made from tool steel, which is hardened, then eroded into shape. This is done by running a high voltage across a copper electrode which has been fashioned into a positive impression of the molded part, a process called spark erosion (aka sink EDM).
It is a very simple mechanism from a design sense, but I am proud to say that this is my first product to ever be sold at a major retailer. It's a great feeling to work with talented industrial designers and their artistic models, and then translate those models into a real product that is sold nationwide.
SENIOR DESIGN
ROBOT LIFT GEARBOX
ROBOT LIFT GEARBOX
This gearbox was designed using a combination of 3d printed and machined components. It is a two-stage gearset with a 3d printed 18T output pulley. The pulley's interface with the brass second stage gearset utilizes heat-staking, which is a process that consists of melting plastic pegs to expand their diameter. This creates a tight fit between the pegs and the component it interfaces with.
There are no moving "live" driveshafts in this gearbox design; rather, the first stage output and the second stage gearset have bearings pressed into them. Each gearset rotates on a structural "dead" axle. This is advantageous to my design, as I needed to integrate the powertrain components into the structure of the gearbox in order to keep weight at a minimum.
When designing this gearbox, one of the key factors in my design choice was runtime. As a former robotics student, I knew firsthand that the quality of a mechanism's manufacturing methods should be driven by the service life of the mechanism. The longevity of this 3D printed heat staked pulley design is dubious at best; however, I needed to create a "quick and dirty" way of axially engaging the pulley through the brass gears which would last through the testing stage and during the presentation only. I also designed the gear spacing center-to-center distance to be .003" larger than the calculated "ideal" value. In industry, gearboxes are generally designed for thousands of hours of runtime with tightly meshed gears, and it will take many days of continuous operation for the meshing gears to properly "wear in" to each other. Adding this extra slop to the gearbox shaft-to-shaft center distance will shorten the service life of the gearbox, but allow it to spin with little resistance as soon as it is assembled.
ROBOT LIFT ASSEMBLY
ROBOT LIFT ASSEMBLY
This mechanism is custom designed to lift a 40lb payload from shelves up to 30" tall while mounted upon a lidar-guided "Turtlebot" robotics platform.
The main structure consists of 2" x 1" 6061-T6 rectangular extrusion with a .062" wall thickness. It is riveted together with aluminum gussets and 3/16" aluminum rivets, and creates a structure rigid enough to resist a severe bending moment while carrying the 40lb payload.
A machined and 3D printed gearbox drives a 5mm pitch Gates timing belt. The belt is anchored to a rolling carriage constrained by the aluminum frame. The carriage rests on steel roller bearings, which gives it the ability to move with low friction compared to the more primitive solution of plastic sliding blocks.
I thoroughly enjoyed working on this project because it allowed me to explore some methods of design with which I had little experience. It was the largest assembly I have ever designed in Creo Parametric. I wanted to know how far I could push our school's arsenal of 3D printers, utilizing components made with Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS). As one of the few lab technicians at the university's rapid prototyping lab, I was able to design, program, and print the parts I used in this assembly myself.
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