Setting tools properly requires exact data. This data has to be correct in terms of both the geometry of the tool and in relation to the CNC machine. If features such as the height of the workpiece and the nose of the spindle aren’t taken into account, crashes occur and money goes down the drain, as does time.
There are numerous ways to set tooling. Some are widespread, some more obscure, but tool setting methods essentially boil down to a few overarching ways.
Touch off
Touching off tools can be done in a variety of ways, the simplest using only a piece of paper. This method is well-loved for its cheapness and simplicity. With the spindle loaded into the machine, the tool is ‘jogged’ down. This means lowering the tool by very small increments, such as one thousandth of an inch at a time.
Whilst jogging the tool down, a piece of paper is moved back and forth until the tool pinches that paper. This signals to the operator that the tool is close to the part without touching it. For a closer touch off, a thinner material such as metal shimstock can be used. This method of touching off isn’t ideal if absolute accuracy is needed, but it’s relatively quick and simple.
Some touch off tools have a button and an LED indicator, which will light up when the machine tool presses the button to the right depth. Dial indicators set into spindles can also help to set a machine’s Z-axis values.
These tool setting methods all work, but they’re heavily prone to human error. One operator may be stricter than another, or have different preferences, or simply have better eyesight.
Lasers
Non-contact lasers offer increased speed and precision when setting tools. Some can also assess tool breakage and changes in geometry that might indicate wear.
Laser-based measuring systems are far more accurate for setting than touching off, but they’re still not perfect. A laser can’t obtain a comprehensive 360-degree view of a tool in the same way that optical measuring solutions can (more on that later).
However, lasers are more stable and reliable than methods requiring more human input. Coolant and debris are ignored by many laser systems, and lasers inherently have micron-level accuracy. There’s far more capability for measuring runout and errors than when simply ‘eyeballing’ a tool using touch off tool setting methods.
Optics
By far the most accurate way of measuring and presetting tools is via optical sensors. ZOLLER machines excel at this. Machines such as the Smile use incident lighting to reveal every precise detail of a tool. With graphical outputs of the tool data and fully automated operation, measuring machines makes presetting both easier and far richer in results.
Another advantage to optical presetters is that, in the case of ZOLLER, they prepare tools offline. This allows setting to be done whilst the machine is running and carrying out jobs. Even if an experienced operator only takes a few minutes to set a tool, eliminating this time from machine stoppage mounts up.
What’s the difference?
As long as tools are being set, why does the method matter?
It matters because the quality of results may be the difference between passing and failing parts. Accurate setting can bridge the gulf between anxious production and stress-free compliance. Jobs being consistently completed within tolerance builds a good reputation.
Finally, ZOLLER’s solutions are Industry 4.0 ready, meaning they’re made with communication, automation, and data transfer in mind.
Find out more about how ZOLLER can transform your shop floor. Contact us today and speak to our dedicated team of experts.