Complete CNC Router Parts [DIY Guide]

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Issue Time: Mar 1,2021

Summary

This Guide to DIY CNC Router Parts is designed for exploration and learning. This page is the home page and visual table of contents. Click the menu above to scroll to a particular part of a typical CNC Router. You’ll get a brief overview of the part together with links that let you drill down and discover more detail about the CNC Router Part.

Use the Guide as an aid to help you make good design choices for your own DIY CNC Router project.

cnc router frame

Frame

The frame supports the machine and provides rigidity to resist cutting forces. For larger routers, there may be a stand with legs or a welded base. Smaller models sit on top of a bench.

CNC Milling Machine Frames are most commonly made of aluminum extrusions. Other possibilities include aluminum plate, steel weldments, or even wood. To get an idea of a really stout frame that could be made of steel weldments and epoxy granite fill, click the link.

cnc router table spoilboard wasteboard

Table

CNC Router Tables can be made from a lot of materials. Shown are aluminum extrusions set up to create T-Slots. A router table might also be made of an expendable material like MDF. In that case, if it is intended to be expendable and replaced when needed, it is usually called a spoilboard or wasteboard.

CNC Router Tables may be bare, but often they will have features to facilitate workholding. For example, T-Slots, a hole grid, or a vacuum table are common.

Wood tops are sensitive to moisture. In fact they can swell enough to cause accuracy issues for the CNC Router. For that reason, aluminum, steel, or phenolic are commonly found on higher end machines. A wooden spoilboard may then be attached atop the tough table below.

cnc router spindle

Spindle

Some say the Spindle is the heart of any CNC Machine. It certainly plays a major role in setting the performance potential of the machine.

At the low end, CNC Routers often use regular hand held routers or even Dremel-style tools as spindles. A step up from that is a spindle with a VFD. At the top of the heap are spindles set up for ATC–Automatic Tool Changers.

cnc router ways axes slides rails linear guides v-groove

Ways

CNC Routers have at least 3 Axes. An axis consists of some kind of sliding “ways” and a drive system that motorizes the axis under computer control.

There are several kinds of sliding ways commonly used for CNC Routers:

V-Grooves involve using ball bearings with wheels that often have a v-shaped groove in them. These wheels ride on the edge of a rail of some kind. The rail could be a triangular edge on an extrusion, or perhaps the edge of a piece of angle iron or something similar. The groove in the wheel need not be V-Shaped, it could also be cupped, for example to ride on a piece of round shaft or a curved edge.

V-Grooves are the cheapest kind of sliding way, but they’re also the least accurate and most prone to backlash. The often require adjustment at frequent intervals for best performance.

Round shafts are what’s depicted in our photos of a CNC Router. They use ball bearings and can be quite a bit better performers. The highest performance are linear slides, which have a prismatic shape and trucks that ride on ball bearings.

cnc axis drive belt leadscrew ballscrew stepper servo motor

Axis Drive

The CNC Router’s Axis Drive system converts rotary motion from a motor of some kind to linear motion to drive the axis on its sliding ways.

There are several common Axis Drive system in use for CNC Routers:

When choosing your drive system, a number of factors must be considered:

Conversion of the motor’s torque to rapid movement speed at the rpm where the motor’s torque peaks.

Elimination of backlash or lost motion, which can reduce the accuracy of cutting as well as lead to other problems.

Cost

More specialized issues such as ballscrew whipping on long axes.

Also part of the drive system are the motors, and any drive connecting the motors to the rest of the drive. Motors are most commonly stepper motors, but servos are a higher performance option.

cnc router controller

CNC Controller

A CNC Router’s Controller is the electronics package that is responsible for executing a g-code programming and sending the necessary electrical signals to cause the motors to move properly to cut the part.

There is a wide variety of CNC Controllers out there for CNC Routers. Pictured is Tormach’s PathPilot, which is used on their whole line of CNC Machines. It’s quite powerful and easy to use.

Controllers can be largely single board without interface to a PC, single board with interface to PC (the UI runs on the PC), or based entirely on a PC with potential accessory boards for motion control.

There will also be a DC power supply to run the motors, drivers for the motors, and various other electronics for things like Limit Switches or spindle control.