There are three main rapid prototype rp machines available suitable for jewelry, toy, medical and other applications requiring high rapid prototype model detail. rpwax.com has made direct rapid prototype rp machine comparison using the identical cad file and has the following conclusion:
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3D Systems makes the Invision HR machine which is an attractively cased rapid prototype (rp) machine, simple to set up and use. The invision hr delivers fair quality and has excellent build speed. However the invision hr system has two major problems, the machine dependability is very low and the models will not direct cast. A liquid mold must be made of each model. Not only does the mold process take a full day to cure but you loose a generation of quality. You still must cut the mold open and make a casting wax copy using jewelers wax. This new wax model is what is used for the casting process.
The Envision Perfactory rp machine uses an upgradeable dlp platform that is small, sleek and quite. The rapid prototype model quality is great. The perfactory requires models to have supports and rapid prototype rp model areas without perfect support structures are subject to warping and distortion. We are working on the ability to cast the model directly. As with the invision hr rp machine a liquid mold can be made. The mold process is slightly time consuming but can now deliver outstanding models. We are now in the process of securing an Envision Perfectory with ERM giving the highest resolution models.
Solidscape makes the Patternmaster, t66, benchtop, t612 and modelmaker rapid prototype rp model machines. The build times are much slower than the above rp machines and the models are more fragile. But the Solidscape machines delivers the best rapid prototype rp model detail. The Solidscape series of machines are the only rp machines that that will direct cast. You can see actual models and castings by clicking here. The rp jewelry models are of the highest detail level. There is no need for a mold prior to casting. If you are like me I want to take a job and deliver the finished product. The Solidscape series of machines does this best.
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Solidscape Precision:
Adjustable Z-axis build layer: from 0.0005 inches (0.013 mm) to 0.0030 inches (0.076 mm)
Achievable accuracy: ± 0.001 inches (0.025 mm) per inch across the X, Y and Z dimensions
Surface finish: 32-63 micro-inches (RMS)
Minimum Feature Size: 0.010 inches (0.254 mm)
Calibrated Configurations for 0.0005, 0.0010, 0.0015, 0.0020, and 0.0030 inches build layer thickness
Maximum build envelope: 12 x 6 x 8.5 inches (30.48 x 15.24 x 21.59 cm)
Uses a non-toxic thermoplastic build material featuring excellent casting qualities (fast melt out, no ash or residue, negligible thermal expansion); highly suitable for direct investment casting and works with a variety of mold-making processes.
Advantages:
It is the most accurate, highest resolution rp machine currently available which can be within +/-0.05mm.
Ideal for parts with very fine feature such as jewelry, toys, medical implements, eyewear, etc.
Super fine layer thickness (0.013mm) is acheivable.
No hand finishing or mold making is required when used for direct casting.