Rapid Prototyping
Rapid prototyping machine
Shaft holder made by rapid prototyping
Medical device made by rapid prototyping
Rapid prototyping covers a variety of processes that, typically, produce low quantities of parts without tooling so that fast turnaround is possible. eMachineShop offers FDM Fused Deposition Modeling which uses a heated nozzle to extrude plastic having a 0.01" diameter onto a work piece. In this type of rapid prototyping, fused plastic is deposited layer by layer according to the 3D model.
Rapid prototyping developed as an outgrowth of liquid photopolymer
research, a class of plastics that solidify under high
intensity ultraviolet laser light. Early rapid prototyping, RP for
short, was created in units called SLA's or stereolithography
apparatus. Fused Deposition Modeling is a newer approach that opened up
a wider range of materials including polycarbonates, ABS plastics, and
others.
Rapid prototyping offers low cost for short runs since no tooling is required. Rapid prototyping allows engineers, designers, managers and end users to check designs for usability, appearance, manufacturability, fit, function, etc., prior to committing to conventional manufacturing. RP speeds the design cycle.
Rapid prototyping can produce almost any 2D or 3D shape including shapes that cannot be made using conventional machining. Examples of a few applications include:
No physical tooling is needed for rapid prototyping.
Cost reduction options include:
- Reducing the weight of the final part
- Using proper part orientation. For example building a cup oriented in the normal way is more economical that building a cup oriented upside down.
Rapid Prototyping Design Considerations
The following applies to eMachineShop rapid prototyping:
- Extrusion diameter (D) .01" or .02"
- Tolerance: +/- 1D.
- Min hole diam: 5D
- Min wall: 3D
- Min cylinder protrusion: 5D
- Min wall thickness with no holes or cutouts: 3D; with holes or cutouts: 10D
- Min height of horizontal slots in side of part: 25D
- Min material between hole and edge or between holes: 4D
- Min acute angle: 30 deg.
- Max size: 5" x 5" x 5".
- Material will be slightly porous and therefore is not appropriate for containers of gases or liquids.
- Surface roughness: ~1,000 Ra for .01" extrusion, ~2,000 for .02" extrusion.
- Small gaps may occur at intricate or curved features.
- Intricate features, such as small lettering are not recommended.
- To thread holes, use Line | Machine | Thread.
Note: to allow for rapid prototyping in the eMachineShop CAD software, choose Job | Materials | ABS for rapid prototyping and check Job | Settings |
Specifications: Auto | Process permissions | Rapid Prototyping.
