Raster-based RP methods are generally faster than ones that fabricate each layer in a vector fashion, and ones that build in thicker layers are faster than those making thin ones. Thus, three dimensional printing (3DP) as exemplified by Z Corporation's products are the speediest - quicker than stereolithography and far faster than some inkjets or fused deposition modeling (FDM). Inkjets which use just a couple of nozzles and make high resolution objects, such as ModelMaker (MM) technologies, are probably the slowest in any side by side race. But that's not the complete story.

It only takes about twenty-five minutes from wheels-up to wheels-down to fly from Boston to New York. But when you take into consideration the time it takes to get to the airport, load the plane and get from the destination airport to the city, it ends up being about the same overall time as taking the train. In just the same way, even though one RP method may be considerably slower than another in a side by side fabrication race, that doesn't necessarily mean that it would lose. One also has to take into consideration the ancillary secondary operations that have to be performed. Fused deposition modeling (FDM) may be slower than stereolithography in making a particular part, but if you can simply wash away the support structure it might be possible to be in business a lot sooner.

Table 1 shows the results of a recent study done for NASA's Marshall Space Flight Center. Note that the slowest technology in the Table takes nearly 7.5 times as long to build the same part as the fastest.

You can get an idea of complete turnaround times from figures published on Accelerated Technologies, Inc. web site. The company is one of the largest US RP service bureaus. They provide a running total for the time it takes for a complete job to be delivered for both selective laser sintering and stereolithography processes. It's typically a little more than 3 days for either process, from executing the PO to a completely finished part.