You can buy a sub £100 3D printer, should you?


I first used a 3D printer back in 2008, it was a HP DesignJet with Soluble support material. Initially I was very impressed with this technology, but I couldn’t ignore how expensive it was. A HP DesignJet in 2008 would cost around £20,000 and a 1Kg cartridge was around £300. Following the 2D printing ink cartridge business model, the cartridges were fitted with a chip to prevent you purchasing print material elsewhere and keep you tied in to the manufacturer for consumables. View on YouTube

This printer was far too expensive for the hobbyist market.

In 2010 I found myself testing the Bits from Bytes BFB3000 3D printer, this printer could be purchased for around £2,500 and used filaments on spools that did not have a chip and did not tie you into the manufacturer for consumables. At this time filament could be purchased for around £30 a spool. View on YouTube

The price point was getting closer to be being within the reach of hobbyists, but still a significant investment.

Later in 2010 I discovered the RepRap project, essentially an open source self-replicating 3D printer. The latest version of RepRap was Mendel, I began my journey into owning my own 3D printer by collecting the bill of materials together, by April 2011 I had my own 3D printer that had cost me around £350 in components to build. View on YouTube

My Reprap Mendel


Fast forward to 2018 and I can purchase a 3D printer kit from China for less than £100, can a printer at this price point be any good? I decided to take the plunge to find out.

The printer

The printer I decided to purchase was the CTC DIY i3 3D printer, I purchased from a UK supplier via eBay, delivered to my door this printer was purchased for the grand total of £90. The CTC i3 is a clone of the Prusa i3 and is the following specification:

Build Volume: 200mm x 200mm x 180mm (LxWxH)

CTC i3 DIY 3D Printer

Layer Resolution: 0.1mm

Material Compatibility: PLA / ABS

Nozzle Diameter: 0.4mm

Heated Bed: Yes

Software: Cura 14.0

Axis Speed: XY 100mm/s, Z 30mm/s

Recommended Nozzle Speed: 35 – 40mm/s

Power Supply: 240W

Size: 360mm x 380mm x 430mm

Transport Package: 500mm x 420mm x 230mm

Package Weight: 9.13Kg

My first thought on receiving the parcel from the courier was “this won’t have been cheap to post, how cheap is the printer going to be?”

3D Printer Package

On opening the package, I was pleasantly surprised, inside there were 2 polystyrene trays and the printer subassemblies were pre-assembled. On closer inspection though things were less impressive, all the pre-assemble parts were loose and fitted with plain nuts and not a spring washer in sight. I knew that I was going to have to rebuild these, there were some nice-looking injection moulded components, but the frame was less pleasing. I knew that this printer was constructed from laser cut plywood, unfortunately the quality was much poorer than I had expected, and I was starting to doubt that this machine would produce any usable prints. View on YouTube

Building the Printer

  1. My first task was to check that nothing was missing, I checked the included parts against the included checklist and found a few items missing:
  • Control board cooling fan

    Tray 1

  • Power Switch
  • Glass Build Plate

There were also a couple of anomalies:

  • Control board different to the instructions
  • Display different, has 5 buttons instead of rotary encoder
  1. My next task was to rebuild the pre-assembled parts, I didn’t want this thing to shake itself apart on its first print, I chose to glue the plywood parts together and add a drop of superglue to each nut after tightening.

    Tray 2

  2. The sub-assemblies went together nicely and once complete the platform was quite sturdy, I was starting to feel a little more optimistic that this would work. One thing I really did not like was the flexible couplings connecting the Z axis threaded rods to the stepper motors, these were rubber tubes with plastic collars to screw down onto them, they are not pretty but maybe they will do the trick.
  3. Next up, the electronics. Everything fit in easily and wiring was straight forward despite the instructions showing different components. Wiring was easy enough, some of the wires were very generous in length and I may need to shorten these at a later stage to neaten the build.

With the build complete I was ready to start testing.


The included software for controlling the printer and slicing models is included on the included CD, when I loaded the CD I found the Chinese version of Cura 14.07. A pleasant surprise on the CD was a PDF instruction manual for the printer version I had been sent, it turns out there were no missing parts and no anomalies the printed instructions were just not for my model.

I haven’t used Cura before, and I don’t speak Chinese, so I decided I should probable download the English version to help things along.

Software Download

Cura 14.07 is an old version from 2014, I decided to stick with the recommended version to check everything works before trying later software.

Relying on the screen shots in the PDF manual, I set the slicer settings in Cura to those recommended by CTC and printed a 100mm x 100mm test cube to check the printer settings. I found that steps/mm were slightly off, but the print quality was pretty good.


Normally I change steps/mm in printer firmware, but I couldn’t be sure which version to use and didn’t want to spend a lot of time playing with many versions to find the correct one. A technique I normally use is to adjust the EEPROM settings using Repetier firmware, unfortunately I couldn’t get Repetier to connect to the printer.

Another workaround is to set steps/mm in gcode, using the M92 command in a start script allows you to set steps/mm for each axis. I carefully calibrated the 3 axis and the extruder and tried another test print; the results were very impressive for such a cheap printer.


OctoPrint allows you to add a Raspberry Pi to your printer to work as a print server and allows you to add a webcam for monitoring prints and the ability to connect to the printer via wi-fi.

I uploaded my slicing profile from the desktop version of Cura to the Raspberry Pi, I can now upload an STL to the 3D printer using a web browser, this works well and is a great investment for any compatible machine.


The CTC i3 DIY 3D printer is very cheap and produces quality prints, should you invest in one? Yes and No.

Raspberry Pi camera bracket printed on CTC i3

If I had never used a 3D printer before and this was my first purchase I would probably have been put off, the learning curve can be quite intimidating, and the instructions are close to useless. The settings are incorrect, and the printer does not work straight out of the box.

If you are familiar with 3D printers and are looking to build your own, this kit can be purchased for less than the sum of the components. With a little tinkering, great prints can be achieved; start upgrading, and this can be converted into a great little machine without breaking the bank.

Would I purchase another? Yes. Will I upgrade it? Yes, starting with those flexible couplings.