Frequently Asked Questions (FAQ)

Answers to Rapid Prototyping questions and information

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questions about rapid prototyping

Rapid Prototyping is the automatic construction of physical objects using additive manufacturing technology. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts.

Rapid Manufacturing, also known as direct digital manufacturing, Instant or On-Demand Manufacturing is a manufacturing process which creates physical parts directly from 3D CAD files or data using computer-controlled additive fabrication techniques without human intervention, also called 3D printing or rapid prototyping. When a small low cost device is used it is also called desktop, or personal manufacturing. The primary distinction between the use of other terms to describe 3D printing is that additive freeform fabrication is solely intended to describe a 3D printed part that is to be used as the final product with minimal post-processing. Whereas other terms used to describe rapid prototyping, additive freeform fabrication and the like are simply alternative ways of describing the 3D printing process itself.

Additive Manufacturing (AM), also known as Direct Digital Manufacturing, is the process of joining materials, such as liquid resin, powders to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies. Synonyms: additive fabrication, additive processes, additive techniques, additive layer manufacturing, layer manufacturing, freeform fabrication.
Source: ASTM International F42 Committee on Additive Manufacturing Technologies

Stereolithography (SL) is a process where high powered ultra-violet lasers are directed into a basin of liquid polymer resin solidifying those areas. The part is created in layers from the bottom up, each layer only thousandths of an inch thick. The result is a precise physical copy of the virtual computer model significantly lower in price than conventional prototyping, and delivered to you in a fraction of the time.
SCICON continues to use the latest in Stereolithography technology to generate solid or flexible, highly detailed functioning parts from your drawings, blueprints, or 3D-CAD files.

Stereolithography was invented by Chuck Hull and introduced by 3D Systems in 1986.

Selective Laser Sintering (SLS®) is an additive manufacturing technique that uses a high power carbon dioxide laser to fuse small particles of plastic powder into three-dimensional objects. The laser selectively fuses powdered material by scanning cross-sections generated from a representation of CAD data on the surface of a powder bed. After each cross-section is scanned, the system lowers the powder bed one layer thickness, applies a new layer of material on top, and repeats the process until the object is completed.

CNC (Computer Numerical Control) is a modern machining method use to perform a wide range of machining tasks on a variety of metal and plastic materials. The primary advantage of CNC machining is that it allows for greatly improved accuracy, efficiency, productivity and safety over other forms of metalworking equipment. Virtually every piece of metalworking equipment is available in the CNC – lathes, drills, milling machines, routers, turret punches, grinders and other high-powered cutting devices.

As a Tier One partner in the 3D System’s 3Dproparts network, we can deliver parts in just about any SLA or SLS material required. We run the following material in our in-house SLA and SLS systems:

– SLA: Accura 25, Accura 50, Accura 60, and Accura Xtreme.
– SLS: DuraForm HST, DuraForm EX, and we are one of only a few service companies worldwide running LaserForm A6. If none of these materials suits the project, our in-house material experts are ready to recommend a material for just about every need.

Ultimately, except in the CNC area which requires native CAD files, our machines require an STL file. However, we can accept a variety of other formats, from which we can create the required STL format. These include:

– Solidworks (.sldprt, .sldasm)
– IGES (.igs, .iges)
– STEP (.stp, .step)
– ProE (.prt)
– CAD systems using ParaSolid kernel (.x_t)
– CAD systems using Polygon surface representation (.obj)
– ZIP archived files (.zip)

Stereolithography: The largest SLA systems can build single-piece parts as large as 26” x 30” x 22”. Larger parts can be built by sectioning and bonding the pieces.

Selective Laser Sintering: The largest SLS systems can build single-piece parts as large as 22″ x 22″ 30″.

The SLA Process:
The SLA process typically produces features as small as 0.006″ to 0.013″ (depending on the machine and build process), at layer resolutions from .001″ to .006″, with an accuracy tolerance of +/- 0.005″ per inch.

The SLS process:
The SLS process typically produces features as small as .030″, at layer resolutions from .004″ to .006″, with an accuracy tolerance of +/- 0.010 per in.

Obviously turn-around time depends on many factors including size and quantity of parts, finishing requirements, etc., but we typically ship SLA parts in one to three days, SLS plastic parts in two to four days, SLS metal parts in three to five days, and urethane parts in five to seven days.

Holes can be cast, but if the hole has critical dimension requirements the hole should be cast undersized, then reamed, or cast without holes and machine afterwards.

For small parts SciCast PMC (Precision Metal Casting) is generally less expensive and are produced faster than DMLS. SciCast PMC parts are built from patterns produced on ultra high-resolution printers so they have a better surface finish and with minimum wall thickness and features about 50% smaller than DMLS. Finally, SciCast PMC offers a wider range of material choices than DMLS.

We can cast very small parts with 0.015″ walls. Any part above one-inch cube should have at least 0.030″ walls. The important thing is that the wall thickness be consistent to avoid shrinkage issues. Generally, we can hold tolerance to +/- 0.005″.

Yes. We have the ability to harden the material in-house. However, if the customer needs hardening to a requested specification, we outsource the process for a nominal additional fee.

Features as small as 0.005″ are easily done. Smaller features can be successfully cast depending on the part size.

This varies with part geometry and material – we can cast larger parts in aluminum than stainless steel. Generally, parts 4″ x 5″ X 2″, or 1.5″ x 2.5″ x 8.5″ can be cast without difficulty. Send us the file and our experts will help determine the castability of any part. We will use a more traditional casting process for parts too large for our precision micro casting process.

Yes. We provide these services, as well.

We have experience casting various grades of aluminum (355, 356, A 380, 7075), stainless steel (303, 304, 316, 316L, 17-4, 440c, 455), Zinc (Z3, Z5, ZA27), gold (10K, 14K, 18K), Silver (sterling, fine silver), nickel (alloy 200, alloy 400, nickel silver), bronze (silicone bronze, phosphor bronze) as well as other materials such as tin, lead, tungsten, titanium and cobalt chrome.