Building a 3D printer for under £200

About three years ago I decided to give 3D printing a go. In this post I wanted to give you a quick overview of how to get started. Most importantly, you can have a lot of fun learning about additive manufacturing without spending a fortune.

UPDATE April 2020: You can help the Covid-19 crisis, by printing masks and protective equipment! Several examples are included below, but there are loads of other examples online.

  • Mask retainers – these relieve stress on the back of care workers’ ears, and also ensure the masks fit tight. I’ve recently been printing these for my local hospital.
    Level of difficulty: Very easy!
  • Printing face sheilds – these take a bit more time, and require some additional parts (namely, a clear plastic shield and rubber band), however these are great for front-line staff
    Level of difficulty: Easy, but takes a bit more time and requires a few extra parts such as plastic visors.
  • Printing ventillator parts – I’d recommend this for the more advanced user. If you’re interested in this I’d recommend having a Google.

Examples of things I’ve printed

Below are a few pics of things I’ve printed. I think you get the most fun out of it when you start designing and printing your own objects, however there are a number of platforms such as Thingiverse which offer a multitude of small platic objects that you can use to clutter up your house.

How 3D printers work

3D printing is a type of additive manufacturing process. Instead of getting a large lump of product, such as plastic or metal and then milling away at it to form it into the shape you require (subtractive manufacturing), additive manufacturing adds material to build up the shape required. In this case, layers of plastic are combined together to form a solid object.

Additive vs. Subtractive manufacturing (credit: Wikipedia)

All that is required is for the printer to literally squidge out molten plastic, layer upon layer, until a new object is formed. This is why 3D printed objects often have horizontal lines when you look at them closely.

There are a wide range of key benefits: the ability to create complex shapes that are difficult to print using standard subtractive manufacturing processes (particularly important in generative design), less material wastage, and the ability to create 3D objects without expensive CNC equipment that is generally only found in a workshop.

Down-sides include slow printing times making it less suitable for mass-production, limitations in the number of materials that can be used, as well as weakenesses associated with how the materials combined.

Selecting the printer

I bought the “Geeetech Acrylic Prusa i3 pro B” from Amazon.

This isn’t a review of all of the different 3D printers out there. However when selecting a printer, here area things you may want to consider, and my suggested answer.

  • The materials that they use to print – e.g. plastics (PLA, ABS etc), resin, metal and so on. Most cheap printers will pring PLA and ABS, which are both standard plastics. PLA is a good choice as it’s made from sugar beet and is biodegradable; it also doesn’t have a strong smell when printing, unlike ABS.
  • Additional capabilities such as laser etching, CNC (drilling) etc. Don’t bother with these unless you want them specifically.
  • Whether it’s commercially supported. Not necessary for hobby work.
  • Whether the printer is already assembled, or whether you’re happy to build it yourself. Cheaper to build yourself, you’ll learn a lot more and you can also customise it (more on that later).

A quick search on Amazon uncovered a few options, many of which were ‘unassembled’. The image to the right shows the model I went for, and is still trending at #2 on Amazon: the “Geeetech Acrylic Prusa i3 pro B”.

What arrived in the post

All of the parts of the printer as they arrived. If you do buy one, make sure you lay out all of the bits in numerical order: all of the bags are numbered and then referred to in the build instructions. This will save you a lot of time!

So, I forked out, and a large box arrived a few days later. The image to the left shows what arrived. Yikes!

So, it turns out that ‘self assembly’ really is self assembly! To be honest I was already mentally prepared, as reviews generally indicated that assembly of the printer took around 8-9 hours.

It did, however, come with relatively clear instructions, which can be found here. It’s not the simplest build I’ve ever completed, but it’s not too bad as long as you follow the instructions to the letter, prep the materials carefully and take your time. Some electrical wiring is required, but it’s mainly limited to plugging in wires into labelled sockets. Note there is a small amount of ‘mains power’ work, although if you follow the instructions you should be fine. It comes with all the screwdrivers and tools you need; it turned out I also needed a hammer, but that’s shouldn’t normally be required ;).

The build

Below I’ve added a series of photos that I took during the build. I’ve added captions to each explaining what you’re seeing, which you can view if you click on them.

Recommendations if you choose to buy one

If you attempt to build this, or another 3D printer, my key lessons learnt are as follows:

  • Take your time – my build took around 10 hours.
  • Set everything out before you start – each of the components, including screws and washers of various sizes, come in separate plastic bags which are all numbered – set them out on the floor so you can immediately find each one when you need them.
  • Ensure screws are tightened appropriately, particularly fixing moving parts to spindles on the motors. If not, they can easily work loose and randomly fail at some point in the future, which is not good as the motors can have a nasty habit of breaking other components if things start falling apart.
  • Take particular time with the wiring – towards the end of the build it can be very tempting just to plug everything in and get it going, but if wires are not carefully tied and cut to the correct length, you create serious problems for yourself later on. It took me around 2 hours to complete the wiring, but spending time on it was totally worth it.
  • Check the nozzle that comes with the printer – you will want to start with a 0.4mm of 0.6mm nozzle. I found my printer shipped with 0.2mm, which can result in nozzle blockages when you’re testing the system. When I finished the build, it worked for about 30 minutes but then it blocked, and my rookie attempts to clear it resulted in melted plastic everywhere and a new extruder assembly being required!

Time to hit ‘print’!

Once you’ve put the printer together, you’ll want to start printing. The printer comes with some instructions for this, and I found the default settings worked pretty much out of the box with surprisingly minimal fiddling.

The Repetier Host software, whilst printing some mask retainers.

The software that comes with the printer is called Repetier Host. It’s a very well designed piece of software that integrates extremely well to the printer’s firmware. You can even save prints to an SD card to allow the printer to print without being tethered to a computer.

In order to print, you simply need to following the procedure below:

  1. Load a 3D object file, which is often in STL format. This can be downloaded from sites such as Thingiverse, as above, or it can be exported from a CAD computer package for an object you’ve designed.
  2. “Slice” the object. This uses a piece of software to convert a solid 3D object into a series of movements of the print head in slices. The slicing software has many parameters that can be set, which include the nozzle size, how solid areas are dealt with (often you want to fil this with a structure rather than solid plastic to save on print time and material), temperatures etc. It’s a bit like the software you use to configure standard paper printers, but more complex.
  3. Make some adjustments to the 3D printer before printing, such as levelling the bed.
  4. Hitting print, and watching as your object is magically transformed from the cyber world to the real world.

Taking your printer to the next level: modding!

The great thing about these ‘Reprap’ design printers is that you can make modifications to the design quite easily: simply by unscrewing elements and then replacing them with new improved designs. I have made a number of modifications to the original design that have significantly improved the print quality. I will cover these off in another post at some point.

I hope you found this blog helpful – if you’re interested in building a printer, please do contact me by leaving a comment below, and I’d be very happy to offer advice and guidance based on my experience.