Prototype Finishing: 3D Printed, Urethane Cast & Machined Parts

3D printing, like any manufacturing process, is not a completely intuitive technology. Printing requires precision: The build platform must be level, part orientation configured – even temperature plays a part in the success of a print. Once a part comes off the machine – be it a 3D printer or traditional CNC platform – it has a unique texture. This texture reveals how the piece was built, in additive or subtractive layers, and can be complementary to a project depending on its application; designers may prefer the texture, as it works well with a desired medium. When the texture interferes with the application, though, it must be improved or removed from the surface of the part.

There are many “DIY” ways to remove texture, however popular options – such as acetone baths for PLA extruded parts – can diminish the tolerances of a part and wear away at important details.  Hand sanding requires a skilled hand and takes hours, making it a less popular option. When a part has critical features or tolerance requirements, it’s best to turn to a professional. Stratasys Direct Manufacturing has expanded in-house finishing services like painting, sanding, hand finishing, high gloss surface treatments, RFI and EMI shielding options. We’ve compiled a few of our favorite finishing examples which best relay the options open to you for your 3D printed, machined or cast part.

3d printing finishing

Case Examples: Smoothing Your Prototype

 Hand Sanding – Bead Blasting – Vapor Polishing – Tumbled – Machine Finish


Project: Menehune Hale Figurine

Process: ID-Light Stereolithography (SL) programmed with thicker layers to reveal build process and deliver the part faster.

Finishing: Non-cosmetic top coat enhances detail and displays features in stark contrast.


Project: Prototype Fan

Process: Fused Deposition Modeling (FDM)

Finishing: Hand sanded in preparation for smooth, high gloss cosmetic paint.


Project: 3D printed Skateboard Design Challenge Winner

Process: Selective Laser Sintering (LS)

Finishing: The skateboard underwent bead blasting to provide a uniform surface texture.


Project: Prototype Case

Process: Stereolithography (SL) with proprietary SC 1000 clear material

Finishing: Hand sanding followed by  clear cosmetic paint for a transparent finish.


Case Examples: Cosmetic Coatings

Master Finish – Primer – Paint – Rubberized Paint – Mold-Tec Finishes – Electroplating – Decals – Artwork


Project: Artist Daksh Sahni Sculpture for Hinge Modern Exhibition

Process: Selective Laser Sintering (LS)

Finishing: Part was subjected to Solid Concepts’ proprietary ColorTek™ LS finishing treatment for a deep, even color. The surface is complemented by a clear gloss top coat.


Project: Artist Ralph Hemick Sculpture for Dena’ina Civic & Convention Center

Process: Stereolithography (SL) master pattern used to create 354 QuantumCast™ urethane creatures

Finishing: SL master patterns were sanded and given a semi-gloss finish before being used to create the urethane molds. Once the urethanes were cast, the parts were given a special tinted matte clear paint, Pantone color matched to the artist’s specifications, for a uniform color across all creatures.


Project: Medical Case Sample

Process: Stereolithography (SL) Master Pattern with inside and outside Master Finish used to create cast urethane mold, which was then cast with Advanced Formula Polymers (AFP)

Finishing: Parts feature cast-in-color with EMI & RFI shielding applied within interior to protect electronics.

Project: Fuel Tank for Oregon State Formula SAE Competition

Process: Selective Laser Sintering (SLS)

Finishing: The tank includes threaded brass inserts. The interior of the tank was coated in a fire retardant paint.


Project: Garden Tool Prototype for Pillar Product Design LLC.

Process: Selective Laser Sintering (LS) using Aluminum Filled Nylon 12 material

Finishing: Outside Master Finish (removing all traces of machine build lines) with a cosmetic top coat for a clean surface. Rubberized Soft Touch Black paint was applied on the handle for a comfortable grip during prototyping testing.


Production Ready: Picture Perfect Finishing for Prototype & End-Use Parts

Dimensional Tolerances – Machining – Master Finish – Assembly – Micro-Welded Inserts


Project: Devon Watch

Process: CNC machined aluminum for the band clasp, watchband links, tuning knob, outer case and back plate; clear CNC machined acrylic compose the watch crystals. The logos were laser cut while the four belts – for hours, minutes and seconds – were silkscreened onto black vinyl. PolyJet 3D printing created the internal components, while QuantumCast™ cast urethanes with shore 90A urethane rubber were used for the wrist band.

Finishing: The CNC’d aluminum was polished and anodized; the CNC’d acrylic crystals were hand polished to optical clarity. PolyJet components were given a cosmetic paint to emulate metal. The pieces were assembled and bonded together to complete an exact replica of the end-use product. This prototype replica was then used for early product photo shoots.


Project: Millipore Muse Cell Analyzer

Process: High Definition Stereolithography (HDSL) master patterns used to create QuantumCast™ parts.; after initial urethane cast prototypes, Stratasys Direct Manufacturing transformed into full production with injection molding and tooling.

Finishing: Hand sanded HDSL master patterns. Color matched cast urethane parts. Assembly of the many urethane pieces to create a ready-for-electronics skin was taken care of by the Stratasys Direct Manufacturing finishing department; the urethane pieces had special Micro-Welded inserts to provide easy assembly. Once Stratasys Direct Manufacturing created the tool and began injection molding, assembly work for all the injection molded units began. Decals were applied to each of the cell analyzers after painting


Project: NEMO – Remotely Operated Underwater Vehicle

Process: Selective Laser Sintering (LS) for the control surfaces; Fused Deposition Modeled body and interior electronics board; Stereolithography Master Patterns for QuantumCast urethane nose cone

Finishing: Each control surface was sanded, painted black and given a glossy top coat. The interior electronics panel was left with a machine finish. SL master patterns were sanded and given a gloss finish to relay the best surface onto the silicone molds used to cast the clear urethanes. The nose cones featured micro-welded inserts to provide a ready-to-assemble product. Two total ROVs were made, and can withstand pressures underwater over 60 meters.

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