CNC differs from lasers in that the machine is rotating tools (or dragging knives) through the material, often at extremely high speeds. Because of this there is a lot more programming involved and many more safety features.
Many CNC machines are in factories doing the same thing time and time again, but ours may never do the same job twice. For this reason programming time can be longer than cutting time for smaller jobs, so we have a minimum order of £120+VAT, instead of £45+VAT for the lasers.
An area that is important to understand is the tool path and what happens to internal corners.
If we tell the CNC to turn 90°, it will do so. But if we are using an 8mm tool, we will get a rounded internal corner the size and shape of the tool will remain uncut, in this case an 8mm diameter / 4mm radius .
This can be undesirable if the slot being cut was clearance for another piece that has 90° edges. There are methods to alleviate this, we can add ‘Dog Bones’ by extending the tool past the corner to give clearance.
Or, depending on material type and thickness, we can program a smaller tool to go in and clean out the corner. This adds cost, but is a way of reducing the effect of the internal radius it is not desirable for your project.
We use CNC tooling (generally) from around 3mm-12mm, but often 6-8mm for many jobs. We do not like to overlap tool paths (the tool path is the route the tool will take through the material).
So, as mentioned, CNC needs significant space between any pieces and also the edges of the material. In most cases a minimum of 20mm between pieces and from the edges is recommended but that can vary between materials.
There are numerous additional processes we can apply with the CNC, including:
In some cases, for small low volume projects, it is easier for us to apply these additions by hand than to program and test them on the CNC.
Additional processes are always likely to add extra cost, but we want your job to be exactly as required, so ask for what you want and we’ll present the options.
From the Biesse Rover J, one of the largest most powerful CNC machines on the market to one of the smallest! We invested in the largest Snapmaker A350 CNC for our Camberwell studio to increase the capabilities we could offer.
‘Snappy’ has a bed size of 320x350mm and can do some very delicate work on small pieces, let us know if you think you have a project that might be suitable.