Helpful Tips

Purchasing a Machining Center for Stone is a large investment you don’t want to get wrong

There are tons of CNC machines available for the marble and granite industry and every manufacturer claims to have the best machines. It is not easy to get the right Machining Center if you don’t have enough experience or don’t know what questions to ask. There are countless features and add-ons to consider although most of them can be attached later, it normally works out cheaper to get them build-in or attached straight away to avoid machine down time later on. The list below is by no means a complete list of what to consider when bying a Machining Center for Stone, but it should give you a good starting point and enough info to find a CNC machine to suit your needs and hopefully increases your countertop, vanity, staircase production or whatever else you produce in your marble and granite workshop.

Budget

Space available

  • determine max size of the machine

What tasks is the machine required to do

  • how many work pieces per day
  • edge profiling
  • edge polishing
  • standard cutouts
  • polishing undermounts
  • drilling holes
  • draining grooves
  • draining boards – flat
  • draining boards – inclined
  • letter engraving
  • bas-relief
  • 2D art work (3-axis)
  • 3D art work (5-axis)
  • cutting slabs
  • polishing slabs
  • capitals and columns

Workbench

  • required size
  • is it easy to get up to setup the suction cups and reference points
  • is it easy to load the stone

Tool holders

  • amount of tool-holders required
  • single tool on each cone
  • multiple tools on one cone(stacked tools)
  • special holder for angled gearbox
  • special holders for draining groove wheels
  • can the machine be programmed for manual tool change

Tool presetting

  • laser or touch probe system
  • can it measure length and radius of tools
  • is it working for stacked tools as well

Suction cups

  • what system is used to position suction cups on the bench correctly
  • double action (suction on top and bottom)
  • single action (suction only on top)
  • height of suction cups to allow free movement for tools
  • are the rubber seals easy to replace
  • vacuum hoses and connection easy to work with
  • do the suction cups allow for easy piece movement (air cushion, retractable PVC or rollers)

Work piece positioning

  • what system is used to position the work piece precisely
  • can the work piece be placed anywhere or are there fixed points

Spindle motor

  • direct or belt driven
  • lock to stop tool from spinning inside the cone
  • sensors to check if tool is present or not

Vacuum pump

  • big volume vacuum tank
  • system to separate air and water to stop water entering the pump
  • will the machine stop on pressure loss or when sucking water

Water

  • is your water pressure sufficient to stop the diamond tools from burning or wearing to fast
  • does the CNC machine manufacturer allow to use recycled water for internal and external tool cooling

other features

  • manual or automatic central greasing system
  • Air conditioned electrical cabinet for warmer areas to avoid overheating
  • low worktable to ease loading and unloading for the operator

Maintenance

  • how long is the warranty period
  • what is covered by the warranty, parts and labour
  • Camera with remote software to solve problems or to order parts
  • free expert telephone and on-line diagnostics

Computer control system

  • what operating system is used (windows, Linux, DOS,..)
  • how many tools can be programmed in
  • how many tools can be programmed in
  • HOLD function to temporarily interrupt the program (e.g. to remove an offcut…)

CAD CAM software package (even more important than the machine)

  • does it come with a full easy to use CAD system
  • get them to draw some of your more complicated benchtops, not only a rectangle table
  • can it import and export DXF files
  • can you use your existing CAD software with the machines post processor (CAM)
  • is there a 3D program simulation to exactly see what the machine is programmed to do

Network connection from office to machine

  • what connection is required to transfer the G-Code or other CNC files
  • ethernet LAN
  • wireless
  • serial RS232

Training

  • how much training will you get (can never be enough)
  • machine training
  • software training

TIP: Ask the machine manufacturer if they can get you in contact with companies which are running their machines in your area. This will allow you to find out how good their service is, how happy other customers are with the machines, if the CNC improved their production output of marble and granite products…

Overall just make sure that the machine can do everything you expect it to do.