piner@pur-phy (Richard Piner) (12/01/89)
A couple of days ago I got a call from a chap down in Indy who has an interesting problem. He needs to measure the shape of a molding in three dimension to within 0.025". And he needs to do it fast. What they want to do is take a molding of a piece of human bone and machine an implant from the molding. He says that the CNC milling machine can do the cutting in under an hour. The problem is getting the digital information to program the mill. So, does anyone know of a commercial system that can measure the shape of an object in three dimensions and do it quickly. Most machine vision systems are not fast enough or accurate enough. Anyone know of a 3d profileometer system that is up to this task? R. Piner
greg@sj.ate.slb.com (Greg Wageman) (12/06/89)
Opinions expressed are the responsibility of the author. In article <2826@pur-phy> piner@pur-phy (Richard Piner) writes: > >A couple of days ago I got a call from a chap down in Indy who >has an interesting problem. He needs to measure the shape of >a molding in three dimension to within 0.025". And he needs to >do it fast. What they want to do is take a molding of a piece of >human bone and machine an implant from the molding. He says >that the CNC milling machine can do the cutting in under an >hour. The problem is getting the digital information to program >the mill. Quite true. Back when I worked at Computervision (now owned by Prime), writing Numerical Control Postprocessors, one of our customers was doing exactly that for replacement knee joints. They were matching the replacement part to the existing bone-end for a more comfortable fit. >So, does anyone know of a commercial system that can measure >the shape of an object in three dimensions and do it quickly. >Most machine vision systems are not fast enough or accurate >enough. Anyone know of a 3d profileometer system that is up to >this task? Sure, they're called "Coordinate Measuring Machines" (CMM's). Like NC machines, you program them to move around your part. Instead of a tool, however, the head ends in a ball-end probe of a known accurate radius. When the probe touches the part, the current coordinate of the machine can be stored. Like NC machine tools, they're very expensive, very heavy, and very accurate. Copyright 1989 Greg Wageman DOMAIN: greg@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!greg San Jose, CA 95110-1397 BIX: gwage CIS: 74016,352 GEnie: G.WAGEMAN Permission granted for not-for-profit reproduction only.