Remember to add a radius to any internal corners that are particularly sharp. Because end-mills and cutting tools are round, it is impossible for CNC machining to create a perfectly sharp internal corner without the use of expensive secondary processes. This is one of the most common mistakes made during the design phase of CNC machining.
If we are talking about internal radii, we should keep them about 30 percent larger than the radius of the cutting tool in order to improve the cutting speed of that feature. In addition to this, you should strive for a radius-to-depth ratio of 1 to 4, and whenever there is any doubt, keep in mind that larger internal radii are always better and cost less to produce.
Are you attempting to jam a square peg into a rectangular hole? For a more secure and snug fit, you can create a dogbone shape by using a relief cut.
Avoiding Deep Pockets is Design Tip Number Two.
A width-to-depth ratio of 1 to 6 or less, or one that is shallower, should be followed by any internal pockets or cavities. The machining process is made more difficult by the presence of deep and narrow pockets, which increase the likelihood of problems such as deflection and tool breakage and make it more challenging to remove the metal shavings and chips produced by the cutting process.
The third piece of design advice is to be aware of the thread depth.
Threading and pre-drilled and tapped holes are two of the most frequently encountered features on CNC parts
The practice of calling out threads that are significantly deeper than they need to be is a common design mistake
Deep threads slow down the manufacturing process, increase the risk of the cutting tool breaking, and do not typically contribute significantly more strength after the first couple of turns
Tip number four: Be wary of having walls that are too thin.
Walls that are excessively thin are not only less sturdy, but they also increase the risk involved in machining and the associated costs. Thin areas tend to lose their rigidity, which makes cnc machining service more difficult to maintain precise dimensions and increases the likelihood that defects caused by machining vibrations, such as chatter or breakthroughs, will occur. When a thin wall is deep or a cantilever is involved, the risk involved is significantly increased.
Design Tip No. 5: Marking the Parts
The addition of marking to a part is an excellent method for identifying both the part and its revision. Wherever it is practical to do so, we always recommend employing engraving, which can be carried out during the machining process. A minimum font size of 20 points is recommended for use with sans-serif text. If you can help it, avoid using raised or embossed markings whenever possible. This is because we have to move the machine around the text rather than just the text itself, which can drive up the cost of that feature significantly.
We strongly suggest that you use laser marking in order to produce high-contrast text or logos accurately and at a low cost if you plan on finishing your part with a color anodize that looks like a finish. Alternate techniques, such as ink stamping or silkscreening, can produce detailed markings with a wider variety of color options.
