Cox Models

Lore & Background

The company, originally named The L. M. Cox Manufacturing Co, Inc., was founded in 1945 by the machinist Roy Cox in Placentia, California. Cox's first products were wooden pop guns, produced in his home garage. When metals became readily available in 1947, Cox turned to new products, beginning with a diecast metal car, which was developed into a 'whip car'. Cox Manufacturing enjoyed large postwar growth due to production of miniature model internal combustion engines and control line model aircraft, moving to a new factory in Santa Ana, California, in 1963. Roy Cox retired in 1969 and sold the company to Leisure Dynamics. A major step toward radio controlled hobby business happened in 1976 with the acquisition of the radio manufacturer 'Airtronics'. By 1983, Leisure Dynamics was facing bankruptcy, and engineer William Selzer joined with a local businessman to purchase the Cox company, forming Aeromil Engineering Company, which changed the name to Cox Hobbies, Incorporated in 1984. In January 1996, Estes Industries purchased Cox Hobbies and relocated operations to Penrose, Colorado. In February 2009, Estes sold surplus Cox inventory to private buyers. After Hobbico's bankruptcy in 2018, MECOA purchased Cox Hobbies in its entirety in 2019, relocating assets to Irwindale, California.

Reader's Guide

Cox Models holds a significant place in the hobby industry as one of its oldest and most iconic multimillion-dollar companies, renowned for miniature internal-combustion engines. The company's history reflects the evolution of the hobby from wooden pop guns to diecast cars, tether cars, control line aircraft, and eventually radio-controlled models. Cox's reed valve engines, particularly the .049 cubic inch variants, are noted for being nearly indestructible, with high production volume engines needing no break-in except for a one-minute rich run. The company's products, such as the AMC Matador police car from the TV series Adam-12 and the PT 19 flight trainer, helped spread the hobby. The acquisition of Airtronics in 1976 marked a major step into radio control. Despite ownership changes—from Leisure Dynamics to Aeromil, Estes, Hobbico, and finally MECOA—the Cox brand and its legacy of durable, high-volume engines have persisted. The relocation of assets to Irwindale, California, amid the COVID-19 pandemic, underscores the enduring value of the Cox product line, trademarks, and original tooling.

Did You Know?

• The company's first contribution to tether car hobby was a cast aluminum midget racer powered by .09 and .15 engines by Cameron Brothers.
• The PT 19 flight trainer taught many people control line flying without risking their own creations.
• Cox reed valve engines are nearly indestructible and need no break-in except for a one-minute rich run.

Origins in a Placentia Garage

Roy Cox grew up around his father's bicycle shop, an environment that naturally cultivated his fascination with mechanical devices. In 1945, he founded The L. M. Cox Manufacturing Co. in Placentia, California, beginning with wooden pop guns built in his home garage. Wood was his material of choice not out of artistic preference but because metal was scarce during World War II. Once metals became plentiful in the United States by 1947, Cox pivoted toward diecast metal products, developing a tethered whip car that could be swung in circles at high speed. The broader hobby scene was already buzzing with nitro- and gasoline-powered tether cars featuring .60 cubic inch engines reaching 100 mph. Cox's first foray into that world was a cast aluminum midget racer powered by Cameron Brothers engines from Chino, California, displacing just .09 and .15 cubic inches. This modest beginning planted the seed for what would become one of the hobby industry's most enduring names.

Postwar Boom and Product Diversification

Postwar demand for miniature internal-combustion engines and control line model aircraft propelled Cox Manufacturing into rapid expansion. By 1963, the company had outgrown its earlier quarters and relocated to a new 80,000-square-foot factory in Santa Ana, California. Within just a few years, three successive expansions pushed the facility to 225,000 square feet, and the product catalog ballooned well beyond engines and aircraft. Cox added slot cars, model rockets, HO scale model trains, and even a full-sized, one-horsepower gasoline-powered chain saw to its lineup. Roy Cox retired in 1969 and sold the company to Leisure Dynamics, a hobby conglomerate that further broadened the range with kites, toy walkie-talkies, and yo-yos. A strategically significant move came in 1976 when Cox acquired Airtronics, a radio manufacturer, positioning the company squarely in the emerging radio-controlled hobby market. This era of aggressive diversification cemented Cox as a multimillion-dollar enterprise and one of the oldest continuously operating names in the hobby world.

A Brand That Kept Changing Hands

The Cox name has passed through more owners than most hobby companies, reflecting the turbulent economics of the industry. When Leisure Dynamics teetered toward bankruptcy by 1983, engineer William Selzer—designer of the beloved Babe Bee .049 aircraft engine—teamed with a local businessman to buy the company, rebranding it Cox Hobbies, Incorporated in 1984. Operations grew but became scattered across multiple leased buildings, prompting a consolidation into a single Corona, California facility in 1990. In January 1996, Estes Industries of Penrose, Colorado, purchased Cox Hobbies and relocated operations to Colorado, shifting marketing toward mass-market products sold in chain and discount stores. By February 2009, Estes sold surplus Cox inventory to private buyers, and the model train line went to Wm. K. Walthers. Hobbico ultimately acquired Estes and its subsidiaries in late 2009. After Hobbico's 2018 bankruptcy, MECOA purchased Cox Hobbies in its entirety in 2019, obtaining all molds, machinery, tooling, and engineering drawings, which were later relocated to Irwindale, California amid pandemic disruptions.

Reed Valve Engines and Iconic Models

Cox's reed valve engines earned a reputation for near-indestructibility, a claim backed by their construction philosophy. The crankcase, cylinder, and fuel tank are all produced from forged stock rather than the more fragile cast alternatives, and the needle valve and carburettor sit behind the cylinder where crash forces are already dissipated before reaching them. This design allowed high-volume production engines to skip a traditional break-in period, requiring only a one-minute rich run before full operation, and ensured that any piston would fit any cylinder of the same size. The .049 cubic-inch displacement glow fuel models became iconic, powering control line and radio-controlled cars, airplanes, and other vehicles from the 1950s onward. The PT 19 flight trainer introduced countless newcomers to control line flying without the risk of losing their own builds, while its all-metal reed valve engines with rubber spinners often survived crashes to be reused in balsa models. The TD-1, with its white plastic body, aluminum wings, and machined crankcase, was a 1950s favorite. Even odd-looking powered Frisbee craft and three-line Skyraider models carried the Cox name into the hands of generations of hobbyists.