A lot of the inquiries we get start with “can you CNC this?” Sometimes there’s a proper drawing attached. Sometimes it’s a photo of a worn part in someone’s hand. Both are fine places to start, but it helps to know what happens between that message and a finished part. This is how the process runs in our shop.

What CNC means

CNC stands for computer numerical control. The machine is still a mill, lathe, router or grinder, the same kinds of machine tools shops have used for a hundred years. The difference is that servo motors move the axes according to a program, instead of a machinist turning handwheels. The program runs the same way every time, and positions are held to within hundredths of a millimeter.

CNC machining is subtractive. You start with a block or bar bigger than the finished part and cut away everything that isn’t the part. Some material is wasted, but for strength, accuracy and surface finish, machining from solid is still hard to beat.

From drawing to G-code

There are three steps before any cutting happens.

CAD. The part has to exist as a 3D model. If the customer only has a paper drawing, or only the broken part, we model it first.
CAM. CAM software turns the model into toolpaths: which cutter, along what path, at what speed, and how deep per pass. The software will happily produce a toolpath that breaks a 3 mm end mill in the first ten seconds. Knowing what will work on the machine still comes from experience.
Post-processing. A post-processor converts the toolpaths into G-code, the plain-text instructions the machine control reads. A line like G01 X50.0 Y20.0 F200 means “move in a straight line to X50, Y20 at a feed of 200.” The format is decades old and every control still uses it.

Where the time goes

Most people assume cutting is the long part. On a one-off job, setup usually takes longer: clamping the workpiece so it can’t move under cutting load, loading and measuring each tool, and telling the control exactly where the stock sits on the table. With a good setup, the cutting is uneventful. A bad setup usually shows up as a scrapped part, sometimes at the very end of the cycle.

After cutting, the part is measured. Calipers and micrometers cover most work, and tighter features get checked with whatever the drawing calls for. A dimension that’s out should be caught on our inspection bench, not after the part is installed in the customer’s machine.

The machine

Every CNC machine has the same main parts:

a controller that reads the G-code and drives everything else
a spindle that holds and turns the cutting tool
a table or chuck that holds the workpiece
servo-driven axes (X, Y and Z on a standard mill) that move the tool and the part relative to each other

We do most of our milled work on 3-axis vertical mills, which cover a large share of what local industry needs.

What CNC is good at

The main advantage is repeatability, more than speed. The first part and the two-hundredth come out the same, which is what you need for production runs, spare parts, and anything that has to fit a mating part. A CNC mill also handles shapes that are slow or impractical by hand: 3D contours, deep pockets, dozens of identical holes in a pattern.

It doesn’t remove the need for skill. The skill moves from the handwheels to programming, setup and tool selection. Someone who doesn’t understand cutting will just make scrap faster on a CNC machine.

Where the parts go

Textbooks mention aerospace and medical implants. Around the industrial zones of Cavite and Laguna the work is more ordinary: replacement parts for production lines, jigs and fixtures for assembly, mold and die components, and machine parts the original supplier no longer makes.

If you have a drawing, a model or just the worn part, that’s enough for us to start a quote. Send it over.