Revolutionizing Mobility with Investment Casting at BraunAbility

Because of the intricate mechanisms needed to allow wheelchair users to enter and exit safely, gaining more space requires intricate modifications to the vehicle’s factory-supplied suspension.

“In the past, Chrysler used a much simpler design, the solid rear axle,” says Sajed Dosenbach, a Design Engineer at BraunAbility. “But in the newer design, the independent rear suspension was a lot more complex.”

Ultimately, this meant the company’s usual in-house fabrication capabilities simply wouldn't be feasible.

Dosenbach knew investment casting would ease the complexity of manufacturing by consolidating parts—not to mention delivering higher strength than sheet-steel stamping—so he gave Signicast a call.

Design for Manufacturability

To implement this new modification, cradle mounts needed to be seamlessly integrated into the Chrysler-designed subassembly beneath the car, resembling the way a trailer hitch effortlessly slides into a sleeve-like hitch receiver. 

Given that this suspension had never been attempted before, Dosenbach had to initiate the process with only an idea, which he then translated into a CAD drawing. It was Signicast’s job to help him transform that idea into the components BraunAbility needed.

Before investing the time and cost of tooling up for a production run, Signicast needed to verify the manufacturability of this entirely new design and ensure it would meet BraunAbility’s rigorous safety and durability testing standards.

In-House Prototyping Capabilities

After running simulations, Signicast’s engineers made CAD models of several design options. Utilizing in-house prototyping capabilities, they transformed 3D printed patterns into production-intent steel prototype parts—exact replicas of the part—on which BraunAbility could perform its real-world tests.

As Dosenbach explains, “That's the best prototype you could ask for because it accurately replicates the final production piece in terms of strength. When prototyping instead of producing a final part, you’re essentially altering the manufacturing method.”

Preventive Prototyping

Most importantly, the ability to revise and improve on the idea using Signicast’s prototyping capabilities led to a successful, workable design.

For example, some test results on the prototype showed that the original design would require greater welding surface area to maintain joint strength. A better solution was to invert a portion of the design—a far easier and more affordable fix during prototyping than after a production run.

After the new design was prototyped in different versions, BraunAbility retested the part—and it passed. “Going through Signicast’s prototyping process was a lot quicker than coming up with a whole new original design, and saved us from wasting money on tooling,” says Dosenbach.

The Most Spacious Wheelchair-Accessible Van on the Road

The BraunAbility Pacifica is gaining traction as the most spacious wheelchair-accessible van on the road. The suspension clearance project, along with

modifications to the interior floorboard, resulted in nearly 20% more space for wheelchair passengers.

“BraunAbility was able to cut inches off the van floor and put their new modified floorboard on,” says Lann Ellis of Signicast. “They’ve captured extra room, and now have the largest cabin space of any modified minivan on the market.”

For Dosenbach, Signicast’s software simulations, real-world prototypes, part consolidation, and in-house machining made the whole project easier to achieve. “The requests I made to Signicast for these parts were very complex on their end. And they always got me what I needed,” he says.

The project also means that wheelchair passengers can now move fully 360 degrees around inside the vehicle’s interior.

And for BraunAbility, that translates to a movement of happy customers.