Initial two-sided cutting path causes problems at high speeds

[matthijskooijman]

When cutting out a rectangle pocket, JSCut generates the following toolpath:

Cutting starts near the middle, with a plunge followed by a fairly long X-axis move. During this move, material is cut away on both sides of the mill bit. Subsequent moves only cut away material on one side of the mill bit, subject to the configured "step over" value.

The problem is that this initial move is a lot more demanding on the mill than the subsequent moves, but they are both executed with the same horizontal cutting speed. This means I have to either lower the cutting speed for the entire cut, or use a faster speed at the risk of things breaking during the initial move.

Is there currently some way to solve this problem? If not, there's two solutions I can imagine (but I'm really a milling novice, so there might well be better solutions here):

• Configure two cut speeds: One for regular cuts and one for "initial cuts" where more than than the "step over" amount of material is being cut.
• Change the toolpath to cut the initial slot using small Y-axis movements. This still has a small initial move that cuts away material on both sides of the bit, but most of the initial cutting is lighter on the mill. To clarify, this is what I'd have in mind:

[tbfleming]

This is a great explanation about the difference between conventional milling and high-speed milling. I've been trying to come up with a high-speed approach off and on over the past few months but keep getting stuck on a never-ending series of border cases. The relief corners in your example are a good example; there's no way to enter that without a 180-degree cutter engagement.

For advanced users, I recommend Autodesk Fusion 360. It's free for startups and hobbyists and has Adaptive Clearing: https://www.youtube.com/watch?v=85C88YrdhHg