Electroplated tools are basic tools for any CNC machinist that works in marble and stone. An electroplated tool is made of a steel core covered with diamonds. Diamonds (grains of abrasives) are secured to the metal surface by the electroplating process.
Electroplated tools for marble working
There are lots of methods to work marble and stone with electroplated tools but you have to take care of their life and performance. Using a tool the wrong way could cause you to waste time and money. An electroplated tool can be used as long as the steel core is covered with its abrasive diamonds.
Electroplated tools are often misused
Often the marble worker, while using a diamond tool with a height of 20 mm, for example, will only make the tool work partially, perhaps using only 4 or 5 mm of the 20 mm available. This way, the upper part will remain unused but the tool will still wear. This is a waste!
One of the reasons why the machinist works like this is because of the spindle power. To avoid overstraining the machine, he works only on a small portion of the tool height. But this is not the right approach!
What is the right way to use diamond tools?
The basic principle for the correct use of an electroplated diamond tool is to use as much of the tool height available. This will ensure that it wears out evenly.
If the CNC machine is not powerful enough (due perhaps to a low-power electrospindle or a weak structure), the solution is to make the diamond tool work only on a portion of its diameter but always on all of its height. In this case, the cutting width is smaller than the diameter of the tool. The solution is to give a step in X-Y that is for example 20% of its diameter. In this way, the stress of the electrospindle and of the whole machine, in general, will be lowered. But the tool will be consumed in an even way, which greatly increases its yield in terms of linear meters that can be worked.
In the images below you can see firstly how NOT to use diamond electroplated tools, and secondly, the right way of doing it, by using the whole height of the diamond tool and cutting deeply into the material.
Solution by changing the feed rate and the pitch
Generally, whether you’re working with a linear or concentric roughing strategy, a basic CAD / CAM software will create the first path of the tool path in which the tool cuts in full (i.e. for its entire diameter), and subsequently, the tool path generated will move to the step you have set. This means that for the first pass it’s necessary to lower the feed rate manually into the machine and then bring it back up to 100% for the second pass.
This manual variation of the feed speed is not possible if the material has to be roughened at different points.
Solution by Adaptive Feed in advanced CAD / CAM software
An advanced software such as Alphacam (also compatible with our “Next” 3 axis CNC stone router) this operation automatically through a function called Adaptive Feed (in other CAD / CAM software it may be called something else). With this function, you can tell the machine to work with a feed speed that is proportional to the amount of material removed.
With adaptive feeding, the processing times can be halved by working in total safety without ever straining the machine too much. This is because the feed speed increases proportionally and automatically, if the cutting width is lower than the specified step. Vice versa, the feed speed decreases proportionally and automatically if the cutting width is greater than the pitch.
In the following image, you can see the Alphacam 2018 screen where the parameters of adaptive forwarding are set.