As an Electrical Engineer student, I am always working on projects to create or changing things to make it better. A lot of my projects require custom PCBs. The problem with manufactures is that they take a long time to deliver and if you want to change something, you would have to design it again and wait another month, also using chemicals to etch the board would require good ventalation and some chemicals can be harmful. So I decided to look for a small CNC Router to see if I can make my own PCBs from scratch. So I stumbled upon the "1610 CNC Router": https://amzn.to/2JdbwGl
So I have bought one, put it together, uploaded a PCB design and hit start. It went completely wrong, one side of the circuit was cut more deep than the other side everytime. At first the board would not hold right with the clamps. So I used strong two sided tape which held the board in place and was flat, but no matter how flat I think I have the board, it was still not completely flat. Knowing only a little about CNC machines, I was stumped. Until I looked on the back on the control board and in the software, where it stated "map height" or "z-prob" which would level and adjust the machine depending on board. Which solved the problem.
The end result was very good, clean circuit boards. The z-prob was very important, as no copper board is completely flat. I also added limit switches to for homing and to make two sided PCBs. I've got the traces as thin as 0.6mm.
I am using a "1610 CNC Router" to engrave my PCB's. I am also using two sided tape to hold the boards to the bed of the machine, which does a better job then the clamps do. This machine would be capable of "z-probing" which allows it to level when making the circuit to get a nice clean even circuit. I have added some limit switches as well to allow homing and to where I can create double sided PCBs. This little machine does a great job making prototype PCBs for a cheap price.