CHOOSING THE TOOLS FOR CNC MACHINES
Modern CNC stone processing machines have a great potential. To get the most out of them, you need to have a wide selection of tools available for each machine. Stone is a specific material that has specific characteristics. The contractor therefore needs to have the right tools at their disposal with regard to the type of stone processed and the type of work required.
Each tool has specific properties that correspond to the type of work required – drilling a hole, longitudinal grooving, collection of waste, etc. To achieve the best results, we first need to answer several questions that will help us decide on the right tools.
What material will the CNC machine be processing?
This is the first criterion when we are selecting diamond cutting tools. The two types of tools most commonly used in stonemasonry are galvanized tools suitable for soft materials and sintered tools suitable for hard materials.
How will the material be processed?
Using a CNC machine we can perform a range of work on tombstones, and decorative or structural elements. The following table lists the main types of work and the recommended tools.
The following table shows a variety of tools suitable for working stone.
| Soft materials (marble, travertine, limestone) | Hard materials (granite, quartzite, sandstone) | |
| Rough grinding (drain, washbasin or shower drop) | segment knives for drops – galvanic | segment knives – sintered |
| Drilling (through or partial holes) | galvanic solid or hollow drills | solid or core sintered drills |
| Cutting (with access from the side or via a hole) | cutters of various lengths, galvanized lace | sintered cutters of various lengths |
| Machining of side profiles | cutters for galvanic diamond profiles, poz. 1 + 2 | sintered cutters for diamond profiles, poz. 1 + 2 |
Cutters used to cut grooves on the underside of stone blocks help remove excess material. This method is used to cut countertops, washbasins, or shower stalls.
Deep groove cutters are available in various sizes (usually around 100 and 50 mm) and can be of various lengths (20 mm, 30 mm). When one side of the cutter wears out, it can be flipped over and used again.
Galvanized and sintered cutters for deep grinding
To drill holes with CNC machines, we use drills of various diameters and lengths. The most common thread is 1/2”. Thin-walled drills made by Marmoelettromeccanica allow for quality drilling without the stone crumbling from below.
Sintered core drills for granite
Single-pass cutters – galvanized cutters for marble, sintered cutters for granite
Cutters are often used to cut larger holes in stone. Unfortunately, the most popular cutting wheels cannot drill from above, only from the sides. If we want to make a hole in the middle of a stone slab, we first need to make a small hole with a drill and then we insert a cutter in the hole. We need to choose the right type of cutter depending on the material we are working with – marble, granite or quartzite all need different types of cutters. A deciding factor is the length of the slab.
To cut side profiles into stone slabs, e.g. countertops, steps or windowsills, we use cutters of various shapes.
A set of profile diamond cutters and grinders
A set of cutters and grinders usually comprises 6 to 7 tools we can use for initial grinding and subsequent polishing of stone slabs of any shape. Each shape is marked with a letter. The most common shapes are listed below.
A list of standard profiles for shaping
Another parameter that determines which set of cutting wheels we need is the thickness of the stone slab. This is typically given in millimetres. In addition to the above-mentioned profiles we can also get sets of cutters of various shapes. One producer of sets of cutters is Marmoelettromeccanica. Each tool in the set should be used in the correct order, from pre-grinding to polishing. We should use the tools in the designated order to achieve optimal results and the best shine.
A possible addition to our tool set is a calibration cutting wheel 00 (also called “the shell”). We can use it for a quick pre-shaping profile which shortens the production time and extends the working life of our other tools. Marmoelettromeccanica produces patented pre-cutting wheels Frangistone and Razorstone. These cutters are composed of sets of diamond wheels of various diameters which pre-grind the required profile.
Pre-cutting wheels Frangistone and Razorstone
Source: Kurier kamieniarski
Author: Grzegorz Gryzło | Published: 20.12.2018
