DESIGNING FOR THE DMLS PROCESSJONATHAN BISSMEYER Senior Quality Engineer

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

ABOUT PROTO LABS

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

OUR EQUIPMENTConcept Laser M2 and Mlab machines

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DESIGNING FOR DMLSNot a replacement for traditional machining, casting, sheet metal fabrication or metal injection molding (MIM)

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

Reduction of components Reduction of weight Quicker assembly times Reduction of cost Complexity

DESIGN GOALS FOR DMLS

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

Complex geometriesDESIGN GOALS FOR DMLS

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

Urban utility bike, EVOAllows riders to easily attach and

detach different components

CASE STUDY: HUGE DESIGN

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

DMLS was used to create the lugs, crankset shell and fork crown

CASE STUDY: HUGE DESIGN

DESIGN LIMITATIONS

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SMALL FEATURE RESOLUTIONMinimum feature size:

0.150 mm (0.006 in.)

Mesh structures

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THIN WALLS(<1 mm/0.040 in.)

Rule of thumb: 40 : 1

height : wall thickness

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SURFACE ROUGHNESS

Material

Build parameters

Part orientation

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SURFACE ROUGHNESSMachine Material Vertical

Sidewall (Ra)

Angled Upfacing Surface (45°) (Ra)

Upfacing Surface (Ra)

Angled Downfacing Surface (45°) (Ra)

Concept Laser M2 (250 mm)

Stainless Steel (316L) 195 225 395 565

Titanium (Ti64 ELI) 215 250 305 335

Aluminum (AlSi10Mg) 250 295 415 435

Inconel 718 350 405 610 960

Concept Laser Mlab (90 mm)

Stainless Steel (316L) 135 170 355 275

Stainless Steel (17-4 PH)

155 185 440 420

Cobalt Chrome 255 135 325 340

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SUPPORTS

Connect the part to the platform

Hold features in place

Prevent warpingPhoto courtesy Concept Laser

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SUPPORT removal processCan be intensive and may require machining, EDM

Design tip: Design parts that will require minimal supports. This will also improve part quality

Photo courtesy Concept Laser

DESIGN CONSIDERATIONS

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INTERNAL FEATURES

Support and powder removal access

Design tip: Lattice structures can be used internally to reduce weight and provide support

Channels, overhangs, self-supporting angles, bridge dimensions

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SELF-SUPPORTING ANGLES

CAD 50 degrees 45 degrees 40 degrees

35 degrees 30 degrees 25 degrees 20 degrees

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OVERHANGSIf the next layer is larger than the previous layer,

it will create an overhang

DMLS has a small allowance for

unsupported overhangs (0.5 mm/0.020 in.)

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CHANNELS AND HOLES

Channels and holes are self-supporting features

Great for conformal cooling applications

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CHANNELS AND HOLESAs the diameter increases, the overhangs increase

8mm(.31”)

6mm(.24”)

5mm(.2”)

15mm(.6”)

12mm(.47”)

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

BRIDGES

1mm 2mm 3mm 4mm 5mm

Minimum allowable unsupported bridge distance is small (~2 mm/0.080 in.)

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INTERNAL STRESSES | WARPAGEChanges in cross-sectional areas can lead to warpage

Large flat surfaces can bend build plates and shear bolts

Design tip: Design in additional material to gradually transition into larger cross-sections

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DESIGN EXAMPLE: REV 1Three-component assembly Supports!

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

DESIGN EXAMPLE: REV 2Reduction of components/assembly time/weight …

BUT…

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DESIGN EXAMPLE: REV 3Best surface finish, small warpage potential

Self-supporting features eliminate need for most supports

ADDIT IVE MANUFACTURING | CNC MACHIN ING | IN JECTION MOLDING

PROTOTYPING OR PRODUCTION

DMLS can be a production method for

complex geometries

DMLS is also a low-cost, quick-turn

method for prototyping

components using actual end-use

materials

OPTIMIZE DESIGN HIGHER VOLUME

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CASE STUDYTRANSITION TO CONVENTIONAL MFG

Total Cost (Tooling + Parts)DMLS

MIM

Part Quantity

Cost

0 100 200 300 400

Breakeven point

CONCLUSIONDMLS opens up new design options,

but it will not replace conventional manufacturing methods

Understanding constraints will maximize benefits of DMLS for part

design

QUESTIONS?