There are much better alternatives to simply speeding up your machine's feedrate for faster milling times. To accomplish this, you must understand that machines are not always operating at the maxiumum (or nominal) feedrate as defined in your template or milling strategy. In fact, they spend most of their time decelerating and accelerating to turn a corner or change direction. Therefore, a toolpath that minimizes these types of movements is always the best way to increase your milling time. Using hyperDENT on the Roland machines, I've actually decreased milling times by more than 20% (for simple crown and bridge cases) while using
slower feedrates than other software packages. For large or more complicated jobs, we've actually cut the milling times in half!
But that's not the only factor. Also note that some toolpaths are inefficient for the task at hand, but unfortunately, some CAM software packages on the market don't have good alternatives. Here's a z-level finishing movement that I commonly see from our competitors for finishing the inside of a crown or coping:
Looks familiar, right? As you can see, the tool spends a lot of time jumping from one side of the coping to the other in order to finish the highest Z-level first and move its way down into the part. I would never recommend a toolpath with such an inefficient technique for surface finishing. Instead, I'd utilize a toolpath where the tool stays engaged with the material and never changes direction by spiraling down, like this:
This example is a bit on the "extreme end" of the spectrum to make a point. However, once you add up the cumulative result of wasted movements similar to these, the milling times can vary significantly.
