Tavaro's rapid growth continued through the late 30s as Switzerland mobilized and France and England declared war on Germany. Tavaro lost a contract, and employees, to Hispano-Suiza, but this was offset by others from the Swiss and German governments. An additional workshop was acquired - the former Cinegram watchmaking works at the corner of rues St-Jean and Beau-Site. But this expansion was not painless, and Tavaro's growing pains would prove nearly insurmountable. Tensions were building among the factory's workforce due to low pay and poor conditions, and a recent war profits tax threatened to virtually wipe out the firm's excess capital, at a time when orders had just been placed for new equipment.
Nothing could prepare Tavaro, however, for May 1940 - when France was invaded and defeated, and Switzerland found itself completely surrounded by the Axis. Pending contracts with France, Holland, Norway and Britain were all suspended and many staff were soon laid off. A September board meeting resigns Tavaro to the geopolitics of the era, recognizing the need to do business with Germany. Soon, the Schwob brothers, bearing a distinctively Jewish last name, tendered their unexpected and "regrettable" resignation.
Tavaro's position grew increasingly precarious; the specter of war had created the firm's success, but the realities of war could now be its ruin. Indeed, market conditions during and immediately following the Great War were hardly favorable to the Swiss armaments industry, and nothing indicated this latest conflict would be any different. To survive, Tavaro had to completely upend its business model, fast, at minimum expense - rebuild a factory, train and retain a new workforce, integrate the new business into the civilian economy, create a brand – all very new to management, who were accustomed to the steady bureaucracy of government buyers.
With the rise of the upper-middle class housewife and widely-available home electricity, a concept had developed in the preceding decades: the electric appliance. To succeed in this burgeoning market, with no brand or distribution network to speak of, Tavaro saw they would have to create something distinctive and radical. Entering a sewing machine industry that was particularly conservative, Tavaro bet on innovation.
The Singer 12W224, one of many models of open-arm basting and darning machines that would serve as the inspiration for ELNA
The firm settled on a design by a Spanish refugee in Switzerland, engineer Ramon Casas Robert. Casas, a refugee from the Spanish Civil War, came from a family of seamstresses, and he would later claim inspiration for Elna's design from open-arm industrial darning machines like the Singer 47W70, in widespread use for garment repair. To this end, Tavaro acquired Casas' holding company in Châtelaine, Elna SA (short for Elektrische Nähmaschine). The firm thus also acquired the intellectual property of Mefina SA, which, in turn, absorbed Electrina Holding Company Monte Carlo, whose patents applied worldwide with the exception of Spain, Portugal and Brazil.
Casas designed a product especially for women, many decades before gendered marketing was commonplace. He opined that "when a woman finishes sewing she wants to get the machine out of the way," so Elna was designed to be portable and easily stored. It weighed less than 7kg, thanks largely to a body made from molded aluminium instead of heavy cast iron. Though sewing machines had been traditionally japanned in black with gold decals, Elna was finished in a distinctive matte green, giving rise to the machine's popular English-language nickname, the Grasshopper. Its carrying case even doubles as an extension table, another widely imitated feature that would eventually become an Elna trademark.
At the Elna works in Châtelaine, Casas, appointed technical advisor, is tasked with creating simplifying his patent into an improved model for mass production. The project is huge: developing a prototype, procuring tooling for production of 20 units daily, hiring/training staff, and calculating time of assembly and cost, with a target price tag of 360 francs - 100 less than a Singer at the time. For lack of tools, parts were acquired from around twenty subcontractors - unsatisfactory from the perspective of cost and quality control.
To expand production, Tavaro acquired additional space in Charmilles, an industrial neighborhood of Geneva, for 680,000 francs. The site was given railway access when an additional 17,400 sq.m. was acquired shortly after, and a line of credit of 100,000 francs was approved. Tavaro now had a total of 6,500 sq.m. of space in a four-story factory, with separate manufacturing, assembly and R&D departments. Tavaro also set up a sales company, Tavaro Representation SA, issuing 500,000 francs in shares, to build a network of representatives and salesmen, in Switzerland and abroad.