Pick the closest match. Rigidity drives how hard you can push.
What is on the bed today?
The bit in the collet.
How the tool meets the material.
Starting values: make a test cut and listen to the machine.
The short version of what two decades of broken end mills teach you.
Pick your machine, your material and the cutter in the collet, and the calculator does the chipload maths for you: feed rate equals RPM times flutes times chipload, derated for how rigid your machine actually is. Treat the output as a proven starting point, make a test cut, and adjust by ear.
Chipload is how thick a bite each cutting edge takes per revolution, measured in mm per tooth. Too thin and the tool rubs, overheats and dulls; too thick and it chatters or snaps. Every recommendation this calculator makes starts from published industrial chipload charts and scales them to your machine class.
A 3018 is a very light engraver, so think shallow and slow: around 0.5 to 1 mm depth per pass in softwood with a 1/8 inch bit at 300 to 800 mm per minute. Aluminium is engraving-only territory on these machines. Select the 3018-class preset and the calculator caps everything to what the machine can genuinely hold.
Yes, within reason. Belt-drive machines can just manage it with a single flute cutter, shallow passes and lubricant. Ballscrew machines with a 1.5 kW spindle handle it properly with care, and steel-frame routers cut it comfortably. The calculator gates aluminium recommendations by machine rigidity, so if your machine cannot realistically do it, it will tell you straight.
Melting means the chipload is too low or the RPM is too high, so the tool rubs instead of cutting. Use a single flute O-flute cutter, keep the chips big, and raise the feed rate before you ever think about slowing down. The calculator enforces a minimum healthy chipload on melt-prone plastics like extruded acrylic, polycarbonate and HDPE.
Adaptive clearing, also called trochoidal or high speed machining, uses a small stepover with a deep cut so the tool is never buried. The thinner effective chip lets you feed harder while the load on the machine stays low and even. The Adaptive mode in this calculator applies those adjustments for you.
For a smooth 3D finish use 8 to 12 percent of the ball diameter. Going finer than that roughly doubles your machining time for almost no visible improvement, and going much coarser leaves visible ridges between passes.
No calculator can guarantee that, including this one. These are proven starting points built from published cutting data and real machine testing, but every machine, cutter and slab of material is different. If a number looks wrong for your setup it probably is: you are always responsible for your own machine.
Want your tool range or machines in this calculator, with proper feeds and speeds and links back to your store? Get in touch and we will sort you out.