This was my first CNC machine, but i have a lot of experience with machines in general. I'm happy with my purchase, but for $220 it's not perfect, but it has potential, and there's very little instructions. If you are new to CNC and Gcode, don't plan on plugging in and engraving something immediately. It includes the basic run software, but you have to have a drawing/editing program to create what you want to cut or engrave. personally i used Inkscape, and had to watch many many videos on how to use it, and many trial cuts to get it figured out and a week later, i'm cutting out some acrylic beautifully.Down to the nuts and bolts. While it does arrive pre-assembled, understand it's probably thrown together on a warped bench with little squareness, and the bolts holding the carriage was barely tightened. I played around trying to tram it and square it for 2 days before i gave up and took everything apart, measured everything and put it together the way it should be. What i discovered was the Z rail rods was incorrectly sized. The rods had a difference of .020" between them. One rod being .005" longer than the frame, and one rod .015" shorter than the frame. so when everything was tightened, it had a warped wave across the Z axis of nearly .050". Luckily i had a small lathe and could shave the .005" off one rod, and used brass shim stock to add .015" to the other. and in the end i was able to reduce the wave to less than .002" in 4 inches of the 12" of travel. the remaining 8" less than 0.0005" Another issue i discovered is there is a lot of runout in all of the axis's that need to be adjusted out by playing with the leadscrew backlash nuts. in the end i was able to get rid of all of the runout... less than .001" of play.. There is also an acrylic piece under the carriage which is for the limit switches.... and it can be modified to gain an extra 2" of travel on the Y axis if needed. I also upgraded the motor to 20,000RPM with a 15 amp power supply.... which works gre