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Article
Publication date: 1 February 2005

Vito R. Gervasi, Adam Schneider and Joshua Rocholl

The purpose of this paper is to share with the solid freeform fabrication community a new procedure and benchmark geometries for evaluating SFF process capabilities. The procedure…

1108

Abstract

Purpose

The purpose of this paper is to share with the solid freeform fabrication community a new procedure and benchmark geometries for evaluating SFF process capabilities. The procedure evaluates the range capability of various SFF and SFF‐based hybrid processes in producing rod and hole elements.

Design/methodology/approach

By following the procedure and using the appropriate combination of benchmark parts the user can determine the minimal rod and hole size capabilities of an SFF or SFF‐based process. Benchmark parts are designed to capture feature size limitations, build angle problems, and aspect ratio capabilities.

Findings

The geometries and procedure were found to work for evaluating simple rod and hole elements resulting from SFF‐based processes.

Research limitations/implications

Future work could address slot and wall features using a similar procedure. Mechanical properties and performance of resulting parts are not within the scope of this procedure.

Practical implications

The procedure and benchmaking geometries could be employed for a range of scales down to the nano scale. The use of this procedure will lead to practical design inputs for the SFF‐based fabrication of components consisting of optimized lattice structures.

Originality/value

Limited published benchmarking procedures are available to the SFF community. This is the first systematic procedure proposed to evaluate SFF processes for “Rod” and “Hole” capabilities.

Details

Rapid Prototyping Journal, vol. 11 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 27 April 2010

Douglas Cook, Vito Gervasi, Robert Rizza, Sheku Kamara and Xue‐Cheng Liu

The purpose of this paper is to determine the most‐practical means of transforming computer‐aided‐design models of custom clubfoot pedorthoses into functional pedorthoses for…

1118

Abstract

Purpose

The purpose of this paper is to determine the most‐practical means of transforming computer‐aided‐design models of custom clubfoot pedorthoses into functional pedorthoses for testing on patients in a clinical trial.

Design/methodology/approach

The materials used in conventional orthosis fabrication are not yet available for solid free‐form fabrication; therefore, to fabricate the pedorthoses, several approaches were considered, including direct manufacturing, additive‐based moulding, laser cutting of foam and combinations of several of these approaches.

Findings

The chosen approach of additively manufacturing the custom hard shell, and moulding the polyurethane‐foam insert, resulted in accurate, durable and effective pedorthoses that fit well, and could be adjusted as needed. The pedorthoses that were produced are currently being tested on the respective patients for their improvement in mobility and degree of clubfoot correction, and will continue through early 2010.

Practical implications

Additive manufacturing provides an ideal approach for generating the custom, end‐use hard‐ and soft‐layer patterns: each pedorthosis is truly unique; and the soft layer has regions of variable thickness. The advantage of this approach is the reduction in labour and the increase in degrees of design freedom available, compared to conventional methods of fabricating orthotic devices. Replacement inserts can be moulded in a matter of hours using this silicone‐moulding approach.

Originality/value

Several new approaches for fabricating custom orthotic devices were explored, and the related results are discussed. The goal of this paper is to convey the potential of the fabrication procedure used and lessons learned on this project to the rapid prototyping and orthotic communities.

Details

Rapid Prototyping Journal, vol. 16 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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