Best settings for CNC

Hey all,
very new to CNC just engraving in a 231mm x 122mm rectangle 1mm deep in a piece of wood. It’s taking over a day I have step down as .2mm and stepover as .3mm using the included flat end mill bit. work speed is 300mm a min. should i have upped any part of this? also how long will the bits last?

You didn’t say what type of wood. That makes a big difference. If you’re doing a hardwood like oak or walnut you have to go much slower than pine or poplar. If you’re doing mesquite or some exotic even slower.

But generally step-down is somewhere between .5 and 1mm. I do a lot of hardwoods and find .5 works well. Stepover on a flat end mill is generally 2/3 of to just less than the cutting diameter. Ball end mills depends on how much curvature and smoothness/detail you’re looking for.

Speeds should be somewhere between 400-600 for hardwoods. 600-1000 for softwoods. Listen to your machine and watch the results. You’ll quickly learn to hear if it’s straining. If it’s chattering you’re going way to fast or deep. I err on the cautious side.

Smaller bits you’ll probably break before you dull them. Otherwise hard to say. Depends on a lot of factors: wood type, quality of bits, how hard you’re pushing it. You’ll see a difference in finish quality if they are dull, but you probably won’t wear them out unless you’re doing a lot of cnc.


Weird totally thought I said hard wood. I think it’s oak. Thanks this was very helpful