Legacy flexilla™ cordless grease gun

Legacy Manufacturing was expanding their successful Flexilla™ product line, and the plans included a new cordless grease gun that would be targeted towards industrial customers in equipment, maintenance, and agricultural markets. Legacy retained Design Integrity (DI) in Chicago to assist with the industrial design and engineering development of the new power tool design with a focus on the plastic housing assembly. DI had previously worked with Legacy on a two-stage manual grease gun, but Legacy was looking to develop a cordless gun with new features, including a new, innovative Rapid Reload™ quick change feature for the refill cartridge.


Legacy Manufacturing is known across the industry as a company that makes products of high quality with differentiating features that set their products apart from the competition. The Flexilla™ brand is an excellent example, which includes a sucessful line of hoses and cords targeted for rugged applications that require high durability and benefit from high visibility.

The new cordless gun would leverage the Flexilla™ brand, and it would incorporate a new Rapid Reload™ feature to make it faster and easier for users to remove and securely reinstall the grease cartridge.

Legacy had a plan already in place to develop the pump mechanism, battery, and charger in collaboration with existing component suppliers. DI was retained to develop the industrial design, the engineering design of the two-shot housing, the new Rapid Reload™ mechanism, and the fits between the housing subassembly and all mating parts (including the battery pack, grease cartridge, pump mechanism, trigger switch, and Rapid Reload™).



The DI team started by studying the product requirements and benchmarking existing cordless grease gun designs. Next, the industrial design (ID) was developed with a rugged aesthetic that was suitable for the intended markets. The grips and handle areas were developed with proper ergonomics including comfortable soft-touch areas for customers that use the tool frequently throughout the day.

DI engineers specified the housing wall thickness and glass-nylon material to meet the durability requirements. Each mating component was properly fit to the housing to ensure that the product would meet Legacy’s quality and reliability specifications. The Rapid Reload™ cartridge replacement mechanism were refined to optimize the time needed to refill the cartridge.

DI’s engineering and ID team members worked closely together throughout the design implementation phase to ensure that the final product met the original design intent. The DI team held bi-weekly status meetings with the Legacy team, as well, to keep everyone up to date on developments and to incorporate Legacy expertise into the final design.

Client Benefit

The DI team collaborated extensively with the Legacy engineering staff throughout the program, and the joint project team was able to get the new tool design ready for production tooling release in a rapid timeframe.

DI’s extensive power tool design experience ensured that the final product would meet the demanding needs of the target markets and end users. As the product transitioned to manufacturing, DI engineers were available to assist with the final details.

The new Flexilla™ cordless grease gun was launched successfully across the market. It has been well received by customers, and it is currently for sale at Home Depot, Tractor Supply, and JBTools.com.

Power Tool Experience

The DI team has extensive experience designing new power tools, including cordless, AC powered, and pneumatic tools. Our portfolio includes work for Snap-on, Bosch, Milwaukee Electric, Sioux Tool, ITW-Paslode, Legacy Manufacturing, and Image Industries.

Power tools have a variety of technical challenges due to the nature of product category. The product category involves motors, gears, mechanisms, moving parts, tools and attachments, switches, variable speeds, clutches, a variety of engineering materials, and abusive environments across various market segments. In addition, tools are subjected to wide temperature variations, and they have stringent safety, quality, and reliabilty requirements.

In the cordless segment, our team has worked with various battery platforms including Ni-Cad, Li-Ion, and NiMH. As battery technologies change with improvements to battery life and performance, the charging requirements change, as well. Our team of electrical and mechanical engineers is available to help our clients to navigate the decisions and development challenges associated with new cordless tool platforms.

Reach out via the link below if your company would like to discuss your plans for new power tools with our team at Design Integrity.


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