Unlike many of the other machines frequently used in the manufacturing industry, coordinate measuring machines (CMMs) have not undergone many drastic changes over the past thirty years. While there have been improvements in software and probe technology, the basic form of the CMM has remained relatively stable, and this means that there is often not a substantial difference in hardware between a new CMM and one that has been in service for years.
For shoppers in the market for an affordable CMM, this is good news: you can easily save a significant amount of money of the sticker price by purchasing a used CMM and making any necessary upgrades after the fact.
When shopping for a used CMM, however, there are a few things potential customers should keep in mind. CMMs are sophisticated pieces of equipment, and it can be difficult for those who are not metrology experts to tell the difference between a great deal and a rip-off. If you want to purchase a used CMM but aren’t sure what to look for, here are three of the most important things to keep in mind.
• Many used CMMs are sold at auction by companies that have gone out of business or are selling off stock, which means that auctioneers may not have a good understanding of what CMMs are actually worth. You may be able to get a deal at auction, but it can be hard to tell until after the gavel has come down.
• An easier way to buy a used CMM equipment is through a dealer with a recognized profile in the world of metrology. Some companies that specialize in new metrology equipment will also sell used CMMs, and can be a good place to look for affordable, high-quality CMMs.
• When purchasing from a CMM dealer, ask whether or not it has undergone a systemic inspection. Any reputable CMM firm will check to make sure it’s used stock is in the best working condition.
You should also remember that finding a CMM that meets your needs and fits your price range is only the beginning. No matter how good the CMM you find is, it will still need to be installed and calibrated correctly. Some of the most common CMM errors come from machines that have not been properly set up, and given the fact that even a small deviance in measurement can seriously compromise accuracy, you should make sure that your used CMM is professionally installed and calibrated by metrology experts.
Furthermore, because it is likely that your used CMM will not be running the most up-to-date software available, it may be worth your while to hire contract CMM programmers to help you find the best CMM software for your production line’s needs. Contract programmers can also help you write new part programs and can advise on how best to integrate your CMM into the rest of your production line.
Used properly, a functioning CMM is one of the most useful tools on a production line. By providing accurate, high-level measurement data, CMMs are invaluable for ensuring quality control and can help you ensure that the parts and products being produced meet blueprint specifications. Buying a used CMM is a great way to save money, and as long as you purchase from a reliable source and have it properly installed, you are sure to find a model you can use for years to come.