Basics of CNC Machining Mills: 4 Design Tips
Having access to modern manufacturing equipment is all well and good, but unless you have the knowledge to make the most of what they can do, the money you invested in them in the first place will have been wasted.
Of course effective CNC machining is only possible if the designs being interpreted by the equipment are well optimized. To that end, here are just a few tips to help beginners get a grip on the basics.
Complexity is the enemy of speed
Complex designs may look good on paper, but in practice they can lead to lengthy machining times and may even be less practical and durable than a simpler equivalent.
For example, whichever types of CNC milling machines you pick to work with, if you want to create a part with a 3D surface featuring curves, it will take significantly longer to complete than an alternative that uses flat surfaces instead.
Likewise it is a bad idea to opt for designs with undercuts, since these need specialist tooling to execute and also involve several setups being added to the machining process, which further drags out the creation of a component.
Engraving text trumps embossing text
Making markings on the surface of a part using a CNC bed mill is straightforward, at least if you choose to go the engraving route. This is because the tooling will only need to remove a relatively small amount of material to etch in part numbers, product names or any relevant codes or instructions that are required.
Conversely, embossed text or numbering requires that a lot more material be removed, which again leads to a protracted production process. It may be tolerable in the case of CNC prototyping or smaller production runs, but for higher volume operations it will be much more sensible to choose engraving instead.
Fillet external corners to remove sharp edges
Clean edges on the exterior of parts may look sleek and stylish, but they will also be invariably sharp and thus pose a risk not only to people but also to other components.
As such, remember to fillet external corners so that they are nicely rounded off, eliminating the issues mentioned above and also giving your parts a more consistent look and feel.
Keep feature height in check
Isolated features which are significantly taller than they are thick will be vulnerable not only during the milling process due to the vibrations involved, but also afterwards once in situ, limiting their durability and also making it harder to create a satisfactory surface finish.
As a rule of thumb, such features should generally have a height which is under four times greater than their width. This will give you the leeway you need to steer clear of common compromises which can come if you are unfamiliar with the best way to design for CNC milling.
Practice makes perfect, so spending time with CNC mills and also checking out designs from experts will also help to inform your own development.