Outer Corner Mode and Adjusting passes – Fusion 360 2D Contour
Another parameter that will allow you to adjust the passes is Lead End Distance.
This parameter will cause that at the end of the pass (at the distance from the end of the pass, specified in this parameter) the feedrate will be changed to the feed value from the feedrate parameter for the tool out (Lead-Out Feedrate).
Sometimes the tool is vulnerable when it comes out of the material. Slowing down the feed rate in these places can prevent the tool from breaking.
The next parameter is also related to the tool in and tool out. The Tangential Fragment Extension Distance parameter will extend the pass at the beginning and end by the value entered in this parameter.
The next parameter, Outer Corner Mode, applies to the outer corners of the tool path.
We can get three different types of tool path in external corners.
The first option, Roll around corner, will cause the toolpath to be rounded at the corners.
With this option, the tool will be in contact with the workpiece all the time. The corner of the machined parts should remain sharp, but after a careful look we can notice a delicate blunt (it does not affect anything and it does not matter, but you can see something there).
If a perfectly sharp corner is required, we will not get this from milling. And the roundings in the tool path, in the corners, have more advantages, which we mentioned earlier.
Another option, Keep sharp corner, will make the tool path not be rounded at the corners.
With this option, the tool will temporarily lose contact with the workpiece. As mentioned earlier, there will be a sharp change in the cutting direction and this is not the best option. It would seem that the corners should be sharper than using the option of rounding the corners, it may be so. But if we care for a perfectly sharp corner, we would rather have to grind, so in this case, this option will not be an advantage.
The advantage may be that some machines (especially the older ones) have a problem with circular interpolation and this option of corner machining is the only one possible.
Another option is Keep sharp corner with loop. This option will add the tool input and output to each corner of the tool path.
In my opinion, using this option we will get the most sharp corner. It can be very helpful when machining “pointed” elements, but it will rarely be used in everyday use.