Reply by bbasiaga

  • Advertise with us

Posted on I’m looking to buy a small format CNC

View bbasiaga's profile


1243 posts in 2878 days

#1 posted 02-05-2018 06:20 PM

2.5 axis can set a cut depth, then move in X and Y directions to make a shape. Like carving a letter. The cut , or Z height remains the same for the whole move.

A 3 axis can move Z, cut depth, Continuously as it moves in X and Y.

Both types can achieve many of the same designs. There are features that ponly a 3axis can do. You’ll need to search around to see some examples. The only direct example I can think of now was when I machined a gear out of plastic that had a done shaped center hub. On the go fishing passes, the machine moved in X Y and Z to trace the exact curve of the shape and leave a nice surface. It did this by going left to right, and top to bottom (picture the gear sitting in the table being cut) to make the dome.

A 2.5 axis machine would only have been able to make a pass at the top of the dome, then step out and do the next layer slightly lower, etc, until it reached the bottom layer. The result would have been like stacking disks to get the shape, as opposed to really carving out the shape. Follow?

Both methods can work. With the right tool selection and stepovers on your passes it can even look dry similar. But the cost in the end is time and/or quality.

There are other cuts that a 3axis can make as well. Like an included sloped groove. This would be hard to do it impossible with the layered approach. Look around online for better examples. I hope this helped some.


-- Part of engineering is to know when to put your calculator down and pick up your tools.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics