Making homemade PCB using the CNC method (drill)

CNC Drilling Method

It consists of sending a file to the CNC machine, and it works in a three-dimensional way with a blade-shaped drill bit, with which it makes the cuts to draw the tracks and separate or isolate them from the rest of the board.

Here I'll give you an example that I made, which obviously didn't turn out very well.
It improves a lot with practice.

But... be careful, not everything that glitters is gold.
We can see countless youtubers where they make their plates, perfect, and in less time than tying your own tie.

There are things to keep in mind.
Copper PCB plates are not perfect, they have curvatures and unevenness that are imperceptible to the eye, but under the drill bit it makes their surface like a roller coaster.
So that the first few times the PCB boards will come out really weird, with tracks that will look very defined in some areas, imperceptible in others, and extremely grooved in others.
So from here on you will get to know something called a height map. A wonder that in practice improves this problem somewhat, but it is not perfect.

Another thing to keep in mind is that this way of working is three-dimensional, even if it doesn't seem like it.
The drill and its bit will be "flying" and traveling on a vertical and horizontal axis, both at the same time, and on a 3rd axis that is known as the "Z axis".
The Z axis is the height of the drill. The Z axis goes up and down to draw a track, or to travel to the start of another.
But it also does so in a sensitive and variable way according to the height map data.
This is something like when you are driving a car and the road is bumpy.
If the car were completely straight in the horizontal plane, it would have a serious accident against the road itself.
The same thing can happen to this Z axis, and sometimes it does, breaking the drill bit against the plate.

A major drawback of this method is that it is a process without reverse.
So if you are unlucky enough to suffer a power outage in the middle of a job with the CNC, oops! Start over? I don't think so... This is the issue....
If while you are happily making your CNC, praising and adoring your machine, and it crashes, oops #2
And in this you have to be very careful with cheap Chinese machines, I have a controller model that crashes even with electrical noises in the environment, sometimes even turning off a light crashes.

Another implicit evil of this system and that few will tell you, is that a system that wears out the tools a lot.
What happens when you are making a plate with 0.2mm tracks and suddenly the blade breaks part of the tip or suffers sudden great wear? This happens quite easily, as the 0.2mm track stops appearing.

You also have to take into account the properties of the machine itself and all its tools, the speeds of the axes, the rotation of the drill, a calculation too far from the tolerances of the same, ends up ruining your work and breaking drills.

The finish and appearance of a pcb board made with the "pcb milling" method, cannot be comparable with that achieved with chemical etching, because we are making deep grooves where the removing a large part of the bakelite, often in excess, and it is very difficult to do it lightly and proportionally.
This also makes it difficult to practice other home screen printing methods, such as plotter lettering or "silk" by toner transfer. For the same reason, there are sections with a lot of unevenness between the tracks and the plate without them.

The manufacturing time is quite slow if you have the typical Chinese machines of 200€ or less.
There are several processes and several cares in the entire process, the fastening, the alignment, the height map.
It should be mentioned that the fastening of the plate has to be strong and uniform, if you don't want the drill to take it for a ride.
In the alignment, someone may say "if you do it with a mask and laser, don't you have to align the plate well?" Well, if I paint it and it comes out wrong, well, I erase it and I can paint it again.

As you break things and you will become more or less frustrated by the natural learning process of this, you will learn and break fewer and fewer things and wear them out much less, but wear and tear is inevitable with this method.
Is it a bad method?
No, but it is a method where there is a significant learning curve, which requires a lot of patience, and requires a lot of care.
With the added disadvantage that it is dirty, noisy, and has a linear cost due to wear and tear because in this method everything is forces and friction.