We used "metrics" similar to the ones spoke of earlier, however we found that the Z-Corp machine (Z402 System) fared much better on our metrics than all of the currently available machines in terms of durability of the parts produced through material options, reliability of the machine, software interface, cost of operation and lets not forget speed. Our metrics was weighted based on the areas of most importance to us.
One of the things that the good people at Z-Corp don't really exploit is the fact that the parts made on their machine can be infiltrated with other materials besides wax. We have found this to be a tremendous advantage because parts infiltrated with stronger materials like Cyanoacrylates, Epoxy or Urethane last longer than wax. Parts infiltrated with these materials can be used in limited functional studies, and can also be finished and used in other applications. Much the same way as parts produced on the high end machines.
Just because the parts made on these so called "Concept Modelers" are supposed to be throw always, does not mean that they shouldn't last till the next meeting. Often times the parts will go through many hands of a team before a sound decision can be made on a design direction. In this case more parts, stronger parts and parts in hand sooner is more important than surface finish or fine detail. If a better surface finish is needed the parts can easily be sanded or scraped in a matter of minutes.
Also, compared to other machines the software that feeds the Z402 can be run on a number of different workstations at a cost of only $5000 each. The benefit here is that parts can be oriented and build files can be saved based on the designers preference. Then the build files can be submitted to the main computer which feeds the machine and built in order based on the date the build file was saved. This is not automatic (no print Que.) but taking the parts out of the machine and adding consumables is not automatic either. No machine can take its own parts out. The advantage however, is the designer has the freedom to orient parts as they see fit and it eliminates the need for a dedicated expert at the machine.
Traditional RP'ers including myself struggle with the accuracy, surface finish and strength issues of Concept Modelers, it seems that we always want to push the envelope and make machines do more than what they were originally intended for ( Concept modeler or Traditional RP). I think the Z402 is a machine that will allow its users to push the envelope and get more bang for their buck. There are definitely applications where one traditional RP machines excels over the others and similarly there are application were each of the concept modelers excels. To us the determining factor was which one will do the most for the money. The answer was clear to us within a very short time!!
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
This archive was generated by hypermail 2.1.2 : Tue Jun 05 2001 - 22:44:52 EEST