AUGUST 2016 Additive Manufacturing

FEATURE / Mold Making

56

By Christina Fuges

Macomb, Michigan-based Baker Aerospace Tooling & Ma-

chining started out as a duplicating company. It’s come a long

way since then. In 1998, the company was one of the first in its

area to purchase a five-axis machine. Now, it has 15 five-axis

machines and more than 40 CNC mills in total. Today, the

company is made up of three units—Baker Aerospace Tooling &

Machining is parent to Baker Machining & Mold and Baker 3D

Solutions, the unit leading the company’s advance into additive

manufacturing. The company’s 3D printing lab includes two

EOS M290 direct metal laser sintering (DMLS) machines and

five Stratasys Fortus fused deposition modeling (FDM) printers.

Mike Misener, director of tooling and additive manufac-

turing for the company, says it was demand from customers

that motivated Baker to start experimenting with metal 3D

printing. The company first used metal AM on fixtures that

Conformal Cooling Is a Mold EnhancementPart of what makes conformal cooling so accessible is that redesign

of the mold is not needed. Baker Aerospace Tooling & Machining

collaborates and educates to advance this and other applications of AM.

These 3D-printed conformal-cooled inserts illustrate some of the

AMAM expertise Baker now applies. The company helps to educate iAM expertise Baker now applies. The company helps to educate BAM expertise Baker now applies. The company helps to educate kAM expertise Baker now applies. The company helps to educate liAM expertise Baker now applies. The company helps to educate ThAM expertise Baker now applies. The company helps to educate hAM expertise Baker now applies. The company helps to educate lAM expertise Baker now applies. The company helps to educate dAM expertise Baker now applies. The company helps to educate

customers on misconceptions surrounding conformal cooling,

including, for example, the idea that a whole new tool must be

created in order to use this. In reality, only select inserts of a tool

must be altered, and only in their internal geometry.

were difficult to machine, but easy to print. It outsourced this

work until the company purchased its first EOS metal printer

in December 2015, followed by a second EOS machine this

past February. Prior to those investments, Baker had ventured

into plastic 3D printing and even that process had helped to

revolutionize how it manufactured fixtures. For example, a

typical production fixture that previously had been machined

was so heavy that it took two people to handle it. Printing in

plastic removed 75 percent of the weight while retaining the

same required rigidity and tolerance, allowing this to become a

one-person application.

Collaborative Approach

Earlier this year, Baker joined forces with Excel RP/Excel Glob-

al, a tooling sourcing company, to sponsor the SA Engineering

AM / Conformal Cooling

additivemanufacturing.media 57

Technology Center, a collaboration facility established by

injection molder SA Engineering (part of SA Automotive, a Tier

1 compression molder) for emerging injection mold trends,

located in Livonia, Michigan. The purpose of the center is to

work with OEMs and Tier suppliers to locally promote and

advance R&D in new technologies for injection molding.

The center, which held its official grand opening this

summer, provides a setting where companies with expertise

in services that support injection molding can co-locate to

develop new technologies on 110- to 3,500-ton presses. This

setting promotes accountability and

collaborative development of repeatable

processes for the new technologies, says

Misener. Through this center Baker will

offer its metal 3D printing expertise for

mold-related applications including con-

formal cooling.

Baker’s expertise in building 3D-printed

mold inserts with conformal cooling has

already helped to improve some process-

es under testing and development at the

center. For example, one customer reported

problems it was having with cold spots in a

heated compression mold. Baker evaluated

the customer’s compression molding pro-

cess and recommended conformal-cooled inserts, which would

allow the mold to maintain heat more evenly. Misener says

the customer was skeptical at first, because there is an ongoing

misconception that adding conformal cooling requires design of

a whole new tool to accommodate it.

“What molders don’t realize is that they can take the tradi-

tional insert size and just change the internal geometry to get

the conformal cooling they need,” he says. “You can take an

existing tool with an in-and-out waterline configuration and

design the internal channels without having to disrupt the entire

design. You are only recreating the internal areas of the insert

that are already existing in the tool. You don’t have to reinvent

the wheel. Conformal cooling is a mold enhancement.” Using

mold flow, cooling and warp analysis, Baker showed the custom-

er how to implement conformal cooling in its existing tools.

He says another point many molders don’t know about

metal 3D-printed inserts with conformal cooling is that they

can be used in production—not just in prototypes—if they

are designed correctly. “There are wrong ways of designing

conformal-cooled inserts,” Misener says. He cites two common

design mistakes:

• “Choking down” the insert, or quickly reducing the size of

the internal chamber, which will inhibit fluid flow.

• Designing a 90-degree bend in the cooling channel, which

will also restrict flow. This is conventional thinking based on

drilled holes and sharp bends.

Misener says both of these design mistakes negate the

benefits of conformal cooling. “It is all in how you design con-

formal cooling with the flow of the internal channels to ensure

a constant flow,” he says. “With conformal cooling, you need a

flowing system, not a sharp-corner system.”

He emphasizes the need for both mold flow and water flow

analysis, both tools that Baker uses in designing conformal

cooling for its customers.

Looking Ahead

According to Misener, an emerging use of AM outside of

conformal cooling is on gate inserts. He explains that there

are a lot of conventional, off-the-shelf cashew gate and

tunnel gate inserts that need to be customized, and making

any modifications conventionally on a CNC machine can

be difficult. But a metal additive process allows any type of

gate design or size to be placed. “We can reach any area with

DMLS,” Misener says. “We grow a custom gate insert for

that tool instead of modifying a shelf item. Instead of trying

to make it work the best you can, DMLS lets you make it

exactly the way you want it.”

The company is one of the supporters of the

new SA Engineering Technology Center,

where it collaborates with other companies

to develop and test injection molding tech-

noloies and solutons. Two of the resources

of the center are seen in these photos, a

285-ton press (above) and 3,500-ton press

(left), both from injection molding machine

maker Engel.