Ask the Expert: Machine Probing
- April 13, 2022
Still using edge finders to pick up work coordinates and touching off cutting tools by hand? Do yourself a favour and invest in a probing system.
By Kip Hanson
I was glad to see that a well-known CNC machine builder has begun offering spindle probes and table-mounted tool setters as an option. Hooray for them, I’m a huge fan of both. This wasn’t always the case, however. While working as an applications engineer for a machine tool distributor sometime during the previous century, I had my share of probing horror stories, among them the time I chucked a Renishaw touch probe across the showroom after I sheared it clean off the toolholder. My bad.
Yes, macro programming and I have had our difficulties over the years.
The good news is that macro programming has largely become a “behind the scenes” thing. Renishaw has a nifty software suite available (Productivity+), and many CAM systems and toolpath simulation software packages now support machine probing. No more figuring out what variable does what or the difference between local and machine variables.
Even the machine tool builder just mentioned agrees that “no machine tool should be without probing” and that companies large and small can “reduce setup times without having to know G-code or macro programming. Those folks in the mostly Great State of California are abundantly correct. For a little more than $5000, a VF-1 buyer can increase the value of his or her investment with the builder’s Wireless Intuitive Probing System (WIPS).
While I won’t say which brand of CNC sits on my imaginary production floor, I will say this: they would all have probing. Of course, there would also be offline tool presetters scattered throughout the shop, but that’s a story for another day.
Don’t get me wrong; I enjoyed learning the use of edge finders and wigglers in vocational-technical school. I still have both in my toolbox. And when Haimer came out with its Universal 3D-Sensor years later, I gladly used it. But even my friend Brendt Holden, the president of Haimer USA, would agree that automatic touch probes save time, eliminate the chance of fat-fingering an offset, and make unattended machining possible. He would also recommend several other productivity boosters, including the aforementioned offline tool presetters, shrink-fit toolholders, and the often-overlooked need for balanced tool assemblies. Again, those are topics for a future column.
In the meantime, take a look at spindle and table-mounted probing systems. They speed setups, certainly, although I might argue that using the machine to pick up tool lengths and work coordinates is entirely old school and can largely be eliminated through the use of zero-point workholding (which I discussed in the previous issue) and offline presetting. Sorry to keep harping on it.
More importantly, probing acts as your eyes and ears when you’re not around. They check for broken or worn tools and either make the appropriate compensation offset, call up a redundant tool, or stop the machine if something has gone awry. They also pave the way for robotic loading and unloading, a topic that’s on many manufacturing minds these days. Check it out and you’ll see. SMT
Technical Editor Kip Hanson has more than 40 years experience in the manufacturing industry. He is the author of Machining for Dummies and Fabricating for Dummies, and has written over 1500 articles (and counting) on a diverse range of topics, among them machining, sheet metal fabrication, 3D printing, automation, software systems, Industry 4.0, and the Industrial Internet of Things.