Twenty years ago these machines were very few, a new concept in inspection and with unreliable software. Each slab of granite and all the slideways had to be painstakingly hand-lapped and what with pioneering measuring hardware and prototype software these machines were very expensive. Only the wealthiest and most progressive businesses and institutions owned maybe one or two. Basically the Car manufacturers bought the majority, next the MOD and lastly research labs & Universities.
Software has been gradually improving, trying to keep up-to-date with the advances in 3D CAD (Computer Aided Design) and integrating with Windows software. The machines themselves have changed very little. There has been some improvement in bearing design (sintered graphite), but only adopted by a few manufacturers. Also a few companies are using bonded ceramic hollow sections (for lightness) for some of the slideway members (particularly the Bridge axis) thus enabling the machine to traverse faster, but the rest have only made cosmetic changes. But the major change nowadays is that most manufacturers make each machine without any hand-lapping or precision machining and take out all inevitable errors - the wobbles, twists, warps etc with powerful software that 'Error Maps' the whole measuring volume of the machine and 'corrects' any measurements taken against this Error Map. This makes for a cheaper machine, but from my precision engineering background I am concerned that any glitches in the Error Mapping could spell big trouble when inspecting - and what about when the machine gets on a bit - will the linear bearings wear?
I am not an agent for any particular CMM manufacturer, though I do recommend one company - and they still make their machines on well proven technology - 5 Billion year old granite, hand-lapped to absolute tolerances!
Now to get up to date - software has leapt forward these past two years; CMM manufacturers are offering good part-exchange deals (but outlay still over ?50k and have lots of second user machines to pass on); the MOD are disposing of all their older CMM's and the technology is easily accessible to all and sundry. As a consequence there is suddenly a second user CMM market, but who to?
... Well there is quite a chance that you are an engineer who has an inspection requirement but has never even seen one of these machines! I am not at all surprised because unless you worked for the MOD, visited Jaguar/Rover etc Cars or had a grand tour of a Universities Metrology department then the chances are quite slim indeed!
I can see that there is a whole new opportunity for companies who have a tighter budget to progress to this 'State-of-the-art' technology and enhance their profile and quality assurance. In fact more and more contracts are being issued with inspection stipulations (ISO 9000 etc) that can make one of these machines an absolute requirement - and all those micrometers, verniers, comparators and height gauges can be dispensed with (but not yet the thread gauges!). I know companies that have invested in this technology (else lose a valuable contract), and with some initial misgivings, yet after a few months are wondering how they ever did without one... As I sell these machines I can see that there are so many companies that would hugely benefit from a CMM but the inspection budget always seems to come as an afterthought...it's like buying new car tyres - we all wish they would just never wear out on the first place! In marketing jargon it's called a distress Purchase. Inspection seems to suffer the same fate, yet it is the 'back end' of manufacturing that the customer often sees - who wants to deliver a component with a hole in the wrong place? If any of this strikes a chord, even if you are not ready for a machine yet, then give me a call or drop me an email. I am an independant CMM Consultant, my Company AKRIBIS METROLOGY. Any advice I give will be judged from your requirements, not my finders fees!