3 Ways 3D Printed Tooling Is Speeding Automotive Prototyping

The end-use applications for additive manufacturing in the automotive market are still limited, partly as a result of the high volumes needed for ongoing vehicle production. But while AM may still be in the early stages of finding its footholds in automotive part production, there are many roles for the technology behind the scenes, in the development and tooling stages.

Even automotive prototyping requires significant volumes, enough that could even be considered “production” quantities in other contexts. To accommodate for comfort, safety, crash and other testing, an automaker might require up to 200 or so identical parts.

Catalysis Additive Tooling, based in Westerville, Ohio, just outside of Columbus, has developed a method for 3D printing of durable, yet affordable tooling, suitable for making automotive prototype parts of many different materials and needs.

This hydroforming tool for an automotive heat shield (described further in Point 3, below) was created through 3D printing sand, infiltrating the sand with resin, and coating the surface to prepare the tool for a prototype manufacturing run. Source: Catalysis Additive Tooling

The company, which we first covered in 2018, was founded by automotive engineers Darrell Stafford and Rick Shibko, who saw prototype automotive tooling as a particular need that could be filled additively. To reduce costs and speed delivery for these tools, Catalysis Additive Tooling has the form 3D printed in sand at a manufacturing partner, and then infiltrates the sand form with resin. The resin “glues” the sand together, making the form durable, and seals and smooths the surface; the material can be further finished to create a tool suitable for thermoforming, vacuum forming and other applications.  

Here are three ways Catalysis’s strategy is being used in automotive development today:

1. Foam Seating

On the right, foam seating made on 3D printed tooling for part testing. The component on the left is a thermoformed part that goes on the back of the seat. 
Source: Catalysis Additive Tooling

The sand-based tooling is suitable for molding of foam materials, enabling automakers to quickly achieve test-ready seating, faster than they could with machined aluminum tooling, which can take several months to produce.  

In one example, Catalysis produced foam seating tooling for the Ford Bronco in just 3 weeks. To machine a tool from billet would have taken 6-8 weeks and cost about $25,000; the sand printed tooling could be made in 3 to 4 weeks, and costs between $10,000 and $12,000 per tool.

Catalysis Additive Tooling has also gone into production with this solution for a different transportation application — the company recently won a job to produce 25,000 seat cushions for end use in golf carts.  

This NVH panel (used to reduce sound in car interiors) was formed using a resin-infiltrated sand tool. Source: Catalysis Additive Tooling

2. Noise, Vibration and Harshness (NVH) Panels

These sound deadening panels are found under interior carpeting, in vehicle sidewalls and in trunk and storage spaces. Made from 1"-thick sheets of nonwoven polypropylene, NVH panels are typically heated and formed in a 250-ton press, then trimmed before installation.

3D printing of the tooling makes it possible to deliver molds for this process more quickly, so that OEMs can iterate through more designs in the same amount of time. Catalysis recently began experimenting with adding water cooling lines through the tools to help control the temperature and pull heat from the tool in use.

A compression forming set for NVH noise-damping parts. Source: Catalysis Additive Tooling

3. Heat Shields

Sheet metal components like this automotive exhaust heat shield (shown here untrimmed) can be made using the bladder hydroforming process. While offering a slower cycle time than stamping, hydroforming can be well-suited to producing smaller prototype quantities of sheet metal parts. Source: Catalysis Additive Tooling

These aluminum sheet metal components are found throughout vehicles — each car can have as many as 10 or 12. In production, heat shields are typically produced through stamping. But Catalysis has adopted a different approach for prototyping these shields: bladder hydroforming. This process is similar to stamping in that it requires a tool, but only half: The metal is pressed into shape by a large liquid-filled bladder capable of producing up to 11,000 psi.

Bladder hydroforming is common in aerospace, but its slower cycle time (about 2-3 minutes per part) has mostly kept it out of automotive production applications. However, coupled with 3D printed sand tooling, the process is an effective way of producing prototype heat shields or even larger sheet metal parts. Only one half of the form needs to be produced up front, and the cycle time is not a major impediment if only 60 to 120 parts might be needed.

What Is Bladder Hydroforming?

Bladder hydroforming is a method of forming material, typically sheet metal, using a die and a bladder filled with hydraulic fluid. The bladder presses the room-temperature metal onto the die to shape it. A simplified schematic of the process is shown below: 

Source: Luigi Chiesa, Wikimedia Commons

There are a few challenges with using bladder hydroforming to prototype heat shields, body panels and other parts that will go on to be made via traditional stamping in mass production. In a stamping press, force is applied straight down so that some areas are addressed before others, whereas with bladder hydroforming, the bladder contacts the entire form at once. “You are uniformly crushing the material onto the tool,” Shibko says. But Catalysis is working to demonstrate that the process produces parts equivalent to stamping, and is collaborating with a partner to bring a large hydroforming press online that can handle larger parts for prototyping.

“This is an enabler for a regular stamper making heat shields in mass production,” Shibko says, because this capacity will enable stamping companies to outsource much of the product development stage to Catalysis and its hydroforming partner. Stamping operations can keep focusing on high-volume production, versus swapping test tools in and out for smaller prototype runs.

Crossing Borders, Pushing Boundaries

While Catalysis Additive Tooling remains headquartered in Ohio, the company recently licensed its technology to a partner in Europe to make the solution available to a larger manufacturing base. Located in Düsseldorf, Germany, innoMold is currently operating the process under the name Catalysis Additive Tooling GmbH and serving Tier 1 automotive suppliers throughout the region.

The company is also exploring what its resin-infiltrated sand solution can do. Prototype and production runs with this tooling have reached into the tens of thousands, but so far the company does not believe it has found the limits.

“Everything has a failure mode somewhere,” Stafford says, “but we don’t know where that is yet. We haven’t hit it.”