Cork Sheet - CNC Milling Guide

Cork is a material that is harvested for commercial use primarily from the bark of the Cork Oak tree.

Since cork has suberin in its cell walls, this makes the cells consist of sealed elements. And having sealed elements make it greater for acoustic insulation and even thermal insulation. This combined with cork's elasticity and its near-impermeability makes it suitable as a material for a wide variety of applications.

The cork industry is generally regarded as environmentally friendly. The sustainability of its production and the easy recycling of cork products and by-products are two of its most distinctive aspects.

Milling cork is very easy on the machine so Evo will handle it perfectly, but it can be tricky to obtain nice results as depending on the cork panel conception, the material can be either brittle, or too elastic.

Follow our general tips below and do some testing as the range of possible cork you can find is very wide.

We recommend that you test your parameters to find the right feed/speed for your combination of tool/material. Start with safe parameters and low depth of cut, and increase progressively to find the sweet spot for your setup. 

Parameters used in the video :

• Machine: Mekanika Evo S / High-Z / Router AMB 1050W
• End mill: Ø 6mm / 2 Flutes Carbide / Downcut spiral
• Feed rate:​ 3 000 mm/min 
• Spindle speed: 14 000 rpm
• Depth of cut: 4 mm

It is very easy to mill cork with a CNC machine, so Pro & Fab will handle it perfectly, but it can be tricky to obtain nice results as depending on the cork panel conception, the material can be either brittle, or too elastic.

Follow our general tips below and do some testing as the range of possible cork you can find is very wide.

We recommend that you test your parameters to find the right feed/speed for your combination of tool/material. Start with safe parameters and low depth of cut, and increase progressively to find the sweet spot for your setup.

Parameter suggestions:

• You can use end mills with high number of flutes, as chip evacuation isn't a problem with cork. 
• Use ramps or helixes instead of plunge to increase your tool's lifetime.
• Chips produced should not be too warm. Warm chips means the tool is rubbing and the chip load is too low (increase feed rate or decrease spindle speed)
•  If the surface finish is not good, it can be related to various things: 
  • check that your stock is fixed strong enough and not vibrating
  • check your tool's edges to see if it is damaged
  • use the shortest tool possible for the job to avoid tool deflection
  • Test different feeds/speeds (most likely: reduce feed rate or increase spindle speed, within the machine's capabilities and while maintaining an acceptable chip load).

You can find here a link to a feed and speed calculator for the most classic materials, and safe values adapted to each of our machines.

MEKANIKA CNC FEED & SPEED CALCULATOR 

IMPORTANT NOTE: this is made to help you find parameters for your milling, but you should always think by yourself and enter cutting parameters that are matching your own setup.
Calculating the theoretical values in this table is easy, but many parameters in your setup may make them unfit for your case. Always start with low engagement and speed, and test deeper/quicker parameters progressively.