3D Printers: The Important Points

3D Printer Guide

Sometimes, it is easy to forget that ordinary folk don’t know much about 3D printing and even less about 3D printers. We should at least give them the Mickey Mouse guide having read the beginners guide to 3D printing.

Many are encouraged to dabble but before you rush to Amazon or your local store, some elementary or basic knowledge is always going to be a good thing.

With that goal in mind, here is a simple guide to what are the main points to consider when parting with your hard earned cash for your first 3D printer. It is not an exhaustive list and neither is it technical by any means – it’s only an introduction to stop you getting lost by understanding 3D printer basics.

Build Area (It’s A Volume)

Build area is a misnomer but you will hear it used all of the time. It’s a volume because it has 3 dimensions representing a space. The build volume refers to the maximum sizes that the 3D printer will support. The dimensions are specified as the length x breadth x height of an item that can be 3D printed. Usually on the device’s specification sheet you will see it specified with 3 numbers X x Y x Z. The important point to remember is that although a larger build area (greater volume) when you multiply all those numbers together sounds good, you may not actually need it.

Build volume is often related as one may expect with price. Bigger is better – right? However, complex or larger 3D prints are often assembled from numerous smaller parts. Check out what you really need before diving in and paying for a machine with a build volume you will never use.

An example of a model made from lots of pieces is given here – 3D Printed Eiffel Tower or this one 3D Printing A Dinosaur.

Extruder (Extrusion).

3D printers consume plastic filament (wire) of which there are several types generally used. The 3D printer heats up the plastic filament and pushes it thought the extruder head ( a bit like a pen nib or nozel), moving about and laying it down layer by layer. As the layers build up, one on top of another, the object slowly materialises in front of your eyes.

This process is often referred to as Fused Deposition Modelling (FDM). Of course if your budget allows, you can purchase 3D printers with multiple extruders which have much greater flexibility. These types of machine are capable of producing objects in multiple colours and can produce gradients, different types of finish etc in a single print run. They can also help to reduce the overall print time by avoiding the need to swap in new filament for each colour.

3D printers with muticolour/multimaterial capabilities are relatively expensive and remain largely within the grasp of professionals and businesses. We are hopeful though that devices for multicolour work will arrive at affordable prices with the next few years.

Plastic Filament

You will often see people talking about their 3D printed items which were made out of PLA (Polylactic Acid) or ABS (Acrylonitrile Butadiene Styrene). Both of these plastic types have their advantages and disadvantages. Generally speaking, ABS will give a better finish than PLA. However, manufacturing ABS is not friendly for the environment – it contains petroleum based compounds. Why use it unless you must? PLA on the other hand is made from renewable biomass sources. You may like to look in more detail at the differences between these two plastic types by looking at the links given above. There is no doubt that each type of plastic has a different finished feel to it and their performance characteristics may or may not be suited to the types of items you wish to produce.

Filament usually comes in one of two diameters – 1.75 mm and 3 mm diameter. There is no real significance to which of these a 3D printer uses. It is highly unlikely that a standard diameter will prevail in the near future at least. Filament for 3D printers is either sold in loose spool form or in cartridges.

The advantage of cartridges is that they are easy to change and result in less problems overall for those getting started. For example, many cartridge based systems will alert the 3D printer when they are close to running out and you will be able to quickly replace it. There is also a lot less chance of making spaghetti bolognese or having 3D printed gremlins. The disadvantage is the choice of colours is more restricted and proprietary based products always have a habit being more expensive. On balance spool based systems are going to be cheaper in the long run and give you a lot more flexibility.

3D Print Resolution

The resolution of a 3D printer is in many ways one of the critical features to pay attention to. Resolution in the world of 3D printing refers not to the number of pixels or dots as it does on your iphone or t.v screen but the level of detail you can achieve in your finished item. In basic terms, how smooth a finish can you achieve and how much detail is possible.

There are two specifications that matter. Firstly how fine can it print in the plane and secondly how fine can the layers be. Think of it this way. Imagine the item being made up of lots of little boxes (cuboids) which are not necessarily cubes all being joined together. In fact a good way to visualise any 3D object is to imagine what it would look like being made up of lots of little boxes (voxels). A 3D printer which effectively delivers higher resolution is going to be best for small objects that have detail in them. The finish will be smoother too. Of course the disadvantage of having really high resolution is it means more work and therefore all else being equal, the 3D printing time will be longer.

3D Printing Speed

The speed of a machine is defined in mm/sec. 3D printers for consumers typically offer upwards of 20mm/sec.

What does this mean? Well those time elapsed videos should make you smile. They give the impression that the object will be built in minutes if not in a few seconds flat. Start thinking in terms hours for simple models that you will find on Thingiverse or elsewhere.

Those embarking on very large objects are looking at days, weeks or even months of manufacturing time. 3D Printing is basically time consuming but there is no waste. Take a look at this video where someone embarked on a mammoth task of 3D printing a kayak. In general, speed is important but it is perhaps not a critical factor in your decision process unless you are into additive manufacturing or rapid prototyping for commercial purposes.

General Advice On Buying A 3D Printer

Unless you have good reasons not to do so, go for the best resolution you can afford over speed – you will happier with that Donald Duck, Transformer, our small selection of free 3D prints or whatever you wish to make.

3D Printers: The Important Points - last modified: June 1st, 2015 by Crew





22 May 2014
Posted by:
Crew