3D Printer Kit: Build a 3D Printer Yourself

Building a personalised 3D printer has never been so popular or so easy. With a 3D printer kit and the information, advice and free plans made available by the RepRap project, you can build your own 3D printer and start printing the things you want. This is a very hands-on project and it helps if there are some technical skills at your disposal.


Things to consider before you start

Instead of purchasing a kit, some people like to source the components they will need from a variety of different places. It is perfectly possible to do this, and to make changes or additions depending on personal preferences. As RepRap is an open source project, sharing any changes or improvements with members of the community is welcomed and will be of benefit to everyone.

In terms of technical expertise, if there are certain parts of the build process that are unfamiliar or prove difficult to accomplish, getting help from an experienced source is recommended. There are some parts that can be bought outright as well as made from scratch, for example the Sanguinololu board with an FTDI chip. If soldering is not a particular skill, it is advisable to purchase this unit rather than attempt to manufacture it.


Printer parts and the build process

All printers have a basic frame that provides a firm structure. It is composed of rods threaded together and connected by printed parts and this is the first thing to be constructed when learning how to build a 3D printer. There are three axes – the Y-axis has horizontal rods and the Z-axis has vertical rods and these are fitted first. The Z-axis is held in place by printed parts at the top of the frame.

The bottom plate is assembled on the smooth rods of the Y-axis and is able to move freely between the front and back of the frame under the control of a belt, which is attached to a stepper motor and pulley. Freedom of movement is helped by bushings or linear bearings, which are glued to the underside of the bottom plate. The RepRap designs that opt for linear bearings usually use LM8UU metal bearings, however, standard bushings are perfectly adequate.

When the X-axis is installed it is controlled by the Z-axis, which moves it up and down the frame. The X-axis in turn controls the extruder, which it can move right and left within the frame. Two printed parts make up the X and Z axes – the X-end idler and the X-end motor. A stepper motor drives the extruder, which has three components – a cold-end, a hot-end with the nozzle and a heat barrier. Once assembled it is mounted on the X-axis carriage.

The extruder has a cold top part, commonly called the Wade extruder, and it is this section that feeds the plastic filament, while the hot bottom part (the hot-end), which has a hole drilled down the vertical axis of a brass bolt, melts and extrudes the plastic.

The three axes move in tandem to produce the printed object on the level print plate. Many printers now include an add-on in the shape of a heated bed, which can reduce the amount of warping caused by uneven cooling of a printed object. An electronics board controls the printing process and there are a number of open-source options for 3D printer kits from which to choose. Stepper motors are best controlled using Pololu stepper motor controllers or equivalent. At the start of the printing process all three axes must be moved to the zero position and optical or mechanical end stops guarantee that they will not move too far.



Neither mechanical nor electronic wizardry is required to build a 3D printer, however, the right tools will ensure a good job is done. For the mechanical build a series of wrenches and hex keys are needed, depending on the type of screws selected. A reliable digital calliper and a small spirit level are necessary for calibrating the frame and the axes. When installing the Z-axis rods a plumb line is required and glue is needed for attaching certain items – a table clamp is also useful. Keep a hairdryer handy for warming bushings and bearings before inserting them.

For assembling the electronic parts of the printer a soldering iron, solder and a cable stripper are required. It’s also possible to create a homemade Sanguinololu board with an FTDI chip that allows the printer to communicate with a computer via the USB port.