With an estimated 150,000 Coordinate measuring machines installed globally its inevitable that many find their way into the used machinery market. Buying a used ‘as-is’ CMM at auction or from a traditional used machinery dealer can ‘snag’ a bargain but at what risk and cost.
A safer alternative purchase is a pre-owned CMM from either an OEM or an accredited 3rd party CMM service organization, where the machine has gone through an internal process which may including retrofitting and upgrading, before the machine is offered back to the market with a warranty.
Today almost all new CMMs remain based upon a granite table with a moving structure manufactured from aluminum or granite/ceramic components – not too dissimilar from machines built back in the 1980’s.
For this article we talked with specialist pre-owned CMM companies and consider the risks and pitfalls associated with buying a used CMM, what to look out for, and how to ensure your CMM investment does not become a liability.
“The great thing about CMM’s is that even the inception models of the late 1970’s and 1980’s are not too far removed from the latest editions in OEM showrooms today” states Tony Tillett Managing Director of UK based Status Metrology Solutions. “They still largely utilize a granite bed, air bearings, servo motor drives and even the CMM’s appearance remains close to the original designs”
What are the typical used CMM pitfalls a customer should look out for?
“Acquiring CMM’s directly from auctions can represent a huge financial risk” states Tony Tillett. “Often CMM’s are sold without computers or software dongles rendering the CMM non-operational and resulting in significant extra costs. CMM’s are high precision and unfortunately any unseen damage could have a catastrophic impact on a machine ability to operate efficiently again. Equally, the auction price is not a true indication of total costs with auction fees, transport costs and engineering time to have it installed and calibrated all extra. If CMM’s are not your specialized field can you really be sure of what you are buying at auction?”
“Pitfalls to look out for are hidden damage such as warped rails or damaged ways. This can usually only be confirmed by performing a calibration on the machine. Other critical items such as CMM controller and software can be upgraded and made current. Most customers do not consider the cost associated with the packing up, shipping, and re-installation; what started out as a small investment can easily become quite large.” comments Jason Miller, Sales Manager of USA based CMM specialists Core Services LLC.
“Customer buying a used CMM need to consider the machine vintage, current configuration and CMM rebuild/retrofit status. A buyer should also review the probe system for compatibility with required CMM measurement tasks . Software also needs to be considered; if the software is out of date, costly maintenance contracts come into play. Is the computer compatible with the CMM software and is it current? Is the CMM controller still supported by the OEM? If not, how much to upgrade?” states Ian Murray Sales Manager at Canadian Measurement Metrology, Inc.
Do CMMs wear out? If so what parts should be replaced and over what time period.
“The CMM Frame is the soundest and stable part of the machine. Frames usually last a very long time with normally the only wear items on the frame being the bearings. Buyers should check to see if the bearings are still commercially available. There is no set time on replacement and some of the first CMMs ever built are still running on original bearings. Again, you should have the machine calibrated to confirm viability of the base machine.” – Jason.
“CMMs are like any other piece of capital equipment. How they are kept and maintained over their years of service, determines how they wear. If the machine has been used in a harsh environment, a more thorough review of the machine would be necessary including bearings and bearing ways, drive belts, motors and counter-balance. Brittle air-lines also need to be replaced.” – Ian.
What typically is the process of a putting a pre-owned CMM back into the market?
“At Core Services we typically strip and clean the entire machine, repair items as needed and replace items with news as necessary. After re-assembly of the machine we run a full calibration and ensure the machine meets or exceeds the original OEM specification before customer shipment.” – Jason
“To get a pre-owned CMM back to market we ensure it’s mechanically sound. Conduct a thorough review of each axis’ drive system, review the air-lines and air bearings, counterbalance and e-stop functions. Obsolete probing is also upgraded” – Ian.
Can I get a full warranty with a pre-owned CMM?
“Most reputable sellers of pre-owned CMMs offer a warranty. Warranties of up to one year are typically available. At the very least, a buyer should expect a 30 day warranty. If the CMM is offered with the latest software it should include 12 months of software upgrades and technical support” – Ian
“All of Core Services Pre-Owned CMM’s come with a full 1 year warranty.” – Jason
CMM software is critical to the CMM measuring function. What is the disadvantage of not having the latest version of software installed on a used CMM?
“If the software on an offered CMM is not the latest version, it may not be compatible with current computer operating systems, and therefore be limited to the ‘horsepower’ of an older computer. The user may not be able to load or manipulate large CAD files. If they decide to upgrade the software at a later date, there could be significant upgrade fees” – Ian.
“The obvious disadvantage of not having the latest version of software is support. With the ongoing changes in Microsoft PC operating systems it is critical to learn if the supplied software will operate on the latest PC operating systems.” – Jason
What are the benefits of new v used CMM?
“The benefit of buying a new CMM is same as buying any new product. Everything on the machine is brand new and current. If cost is not an issue, then the new CMM is the best way to go. But if saving money and getting a comparable product at a substantial savings is important then a good reliable updated CMM is a viable option.” – Jason
“There are many benefits of buying new v used including the machine being supplied, to the buyers configuration, with the latest software, the latest probing, latest electronics, 12+ months warranty, etc. A used machine can be configured as needed, however, the frame and internal components come with ‘history’. A good idea of where the machine was used and installed previously can offer an insight as to what you might expect to be done in the machines overhaul. -Ian
What is the typical cost advantage of used v new?
“Typically, there is anywhere from a 30% to 50% cost saving over used vs new. With upgraded controls and software, a used CMM should last as long and perform the same as a new machine.” – Jason
“Used machines are significantly less expense than their new machine counterpart. Depending on the vintage of the used machine, a buyer should expect to save anywhere from 30% to 60% of the cost of new.” – Ian
What life expectancy can I expect from a used CMM?
“With upgraded controls and software, a used CMM should last as long and perform the same as a new machine.” –Jason
“A used machine that has been retrofit and refurbished, is essentially a certified pre-owned CMM. A buyer should expect the same longevity of a new machine.” – Ian
Many CMMs were produced by companies that no longer exist. Is this an issue?
“It can be an issue in the course of the machine over-haul. If the original manufacturer no longer exists, their proprietary parts availability and technology can become an issue. With that said, most reputable used machine re-sellers have access to aftermarket parts and accessories.” – Ian
“It can be a problem if the defunct OEM used proprietary parts that are no longer available. At Core Services, LLC we specialize on machines built by Sheffield Measurement and we are able to repair and rebuild almost all the parts for these machines.” – Jason
Can a CMM that was originally supplied as a touch-probe CMM be updated for tactile scanning?
“Yes. However, the controller of the machine would most likely need to be changed out. Renishaw offers a wide variety of UCC universal CMM controllers for both tactile and scanning applications.” – Jason
“If it couldn’t, the used machine market wouldn’t be as buoyant as it is. Upgrading to tactile scanning can be a simple undertaking if the machine controller and probe head is pre-configured for this upgrade. Or the upgrade can be more complex with the requirement of a controller and probe upgrade. In either case, it is absolutely possible to upgrade a touch-probe CMM to tactile scanning.” – Ian
“Today a CMM retrofitted with new controller, PC and software offers significantly faster and more versatile performance than it did 10 years ago. Available CMM sensor technology, including tactile scanning, optical, laser scanning and high accuracy probing, are all available to be enhance CMM measuring capabilities. Great news, as most pre-owned CMM’s structures have been maintained properly, regularly serviced and can be retrofitted with these latest hardware and sensor technologies to breath a whole new life into CMM performance” – Tony
So What Price a Used CMM?
If you buy a pre-owned CMM from an OEM or accredited 3rd party CMM service organization with the latest software, machine warranty and turnkey installation services you can definitely save over purchasing new and eliminate almost all risks and at a fixed price.
Remember, the next time you receive an unsolicited email offering you a “Used CMM at an Unbelievable Price”, the guy whose name is on the email has in all probability never seen the machine and knows almost nothing about its condition and history. It may even be your responsibility to reinstate the quality room that must be torn-down to allow for the CMM removal. As with any used equipment purchase ‘buyer beware’; perform as much research and due diligence as you would a new machine purchase. Ensure the software and probing has all of the functionality needed for the measurement tasks envisaged – now and in the future….
And resist the impulse CMM purchase; it could cost you much more than you bargained for!!!.
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