Deep & slower or shallow & faster?

[conanh]

Still getting started with CNC routing, so I'm trying to learn as much as I can.

I saw a video the other day that mentioned machining (metal) at a depth to take advantage of the full cutting length of the flute. The reasoning was that it would wear the bit out evenly so you'd be able to get more cutting life from it. So, that got me thinking.

For routing wood, it it better to do deeper passes so more of the bit is cutting, and thus go slower? Or is it better to to do shallower but faster cuts?

Is one generally better, or are there situations where it's best to choose one over the other and vise versa?

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[ger21]

For maximum tool life, cut full depth and full speed. The only reason to go slower is a lack of machine rigidity, power, or cut quality.

Is one generally better, or are there situations where it's best to choose one over the other and vise versa?

If tool life is your main goal, cut as deep and as fast as you can.
But as I mentioned, there are other factors that come into play. Sometimes you need to cut shallower to achieve a better cut quality. You can do both; make several shallow roughing passes followed by a full depth finish pass. The tip will still wear out faster this way, but you can get a cleaner cut over most of the edge this way.