Newcomers to the design and 3D printing world are sometimes surprised by how much 3D printing can cost. Even more commonly, it can be difficult to identify why some parts may cost more than others, and often the end cost can seem random or hard to predict. Underneath this apparent chaos however, the price of your parts is carefully calculated from the properties of the 3D models.
3D printing is still quite a young industry, and so standardised pricing for certain types of part doesn't exist. As such, you'll find that different 3D printing service providers sometimes offer very different prices for manufacturing the same part. Sometimes this is due to differing quality, service and turnaround times however, so you should shop around carefully for the best combination of service, price and speed to avoid disappointment.
The exact costing formulas used by 3D printing services can be a closely guarded secret, and no two are exactly alike. At Printpool, we are quite open about how we price our parts, but some other bureau services prefer not to share the exact formulas.
Our pricing formula is very simple. We calculate the volume of the part in millimetres (cubic centimetres) and multiply it by a series of constants representing the process, material and complexity of the part.
Although some suppliers have more complex pricing structures, almost all of them will take these factors into account. Let's examine each of them more carefully.
By far the most important factor, the price of 3D printed parts are very sensitive to their size. As a general rule of thumb, the price to 3D print a part depends on a cubic law with its overall size/scale. This means that if you double the size of your design, the price increases by a factor of eight. If you triple it, the price increases by a factor of 27. Make a part 10x larger, and it will cost an eye-watering 1000x more money. Many service providers, Printpool included, do have a minimum part cost however. Ours is £7.50, but this reduces if multiple copies of the same part are ordered.
The type of 3D printing process also has a big effect. Often there are a few different types of 3D printing that could work for a given 3D model. Other times the decision may be made for you by the shape of your 3D model, and only one type of 3D printing will be suitable anyway. FDM (Extrusion) 3D printing is usually a cheaper option, while SLA (resin) 3D printing is often more expensive. This is due to the running costs of the machines, and the regularity with which consumable parts need to be replaced, as well as the base material costs of each option.
Some 3D printing materials are simply more expensive to buy in their raw form, and so 3D prints made from that material will cost proportionally more also. Our FBGR Onyx material, for example, costs us roughly 9x more to buy in than our cheapest material, Recycled PLA, gram for gram. A lot of this cost gets passed across when pricing parts in different materials.
Although it is possible to design parts that are entirely self-supporting, the majority of the parts that we receive for printing will require support structures. Support structures prevent the 3D printer from trying to build on 'empty space', and are essential when 3D printing designs that have overhangs. The support structures also help parts resist warping if they are made using SLA 3D printing.
Parts with a lot of support structures, or support structures that are dense and difficult to remove, will cost more money. This is partly due to the increased material usage, as supports are usually made from the same materials as the model. Part of the increased costs come from increased labour however, as support structures often need to be removed manually during post-processing stages.
Generally speaking, most complexity is 'free' when it comes to 3D printing, as Avi Reichental, then CEO of additive manufacturing giant 3D Systems, famously said during his celebrated TED talk. In some cases though, particularly when surfaces need to be finished manually, more complex surfaces can add some cost. It can be useful to ask your service provider if this is the case when requesting a quote.
Usually with complex features like lattice structures, the reduction in material costs greatly outweighs any additional costs based on complexity. Care should still be taken to avoid support placements in difficult to access areas however, to reduce labour costs.
Producing large quantities of one design can slightly reduce the unit costs. People unfamiliar with 3D printing often overestimate the size of the effect however. Unlike with some manufacturing processes such as injection moulding, 3D printing technologies don't have much of an economy of scale.
As the pricing formulas used as largely based on the amount of material used rather than the complexity of the design, unit costs are not hugely affected by printing multiples. Some time can be saved by running pre-optimised machine programs however, so very large quantities will be a little cheaper.
As with every form of manufacturing, the sooner you require a part or component, the more you can expect to spend. Customers requiring rush orders will always pay a premium, but that doesn't mean that 3D printing is a bad way to go for quick prototyping. A base level turnaround for injection moulding or CNC machining is still much slower than for 3D printing, as the 3D printing process doesn't really require any setup. It is not unreasonable to expect 3D prints in 2-4 days as a baseline level of service, and to pay more for a faster turnaround than that.
When compared to 3D printing your own parts in-house, a service bureau can seem like a very expensive option. Very high multiples on the base material cost can be expected, and often the turnaround times will be somewhat slower than would be possible when 3D printing parts yourself.
Interestingly, over 75% of Printpool's customers already have 3D printers available in-house. There are a number of reasons that they don't use their own printers however, and come to us.
Each of these reasons gives an interesting insight into why 3D printing in-house might not be the cheapest option for you. There is no such thing as a 3D printer that will manufacture everything well, despite what 3D printer resellers might suggest. Post-processing procedures vary a lot between machines also, and can add significant expense. Each design should be carefully matched to the best process and material for the job, and to do this requires access to lots of different technology and material types that would be impractical to run in-house.
Most 3D printers also require high levels of maintenance. If your primary business purpose is 3D printing (like us) then this is no problem. If, on the other hand, you're more interested in design or creating new technology - perhaps your time would be better spent elsewhere.
Finally, successful 3D printing requires a high level of expertise and knowhow. Unless 3D printing is core to your processes and technology there is very little business need to develop or hire for this, and your time and money may be better spent on design rather than troubleshooting a misbehaving machine.
These reasons together make clear that sometimes it cab be far cheaper to outsource your 3D printing requirements to a specialist service like Printpool, rather than bring it in-house. If you are working on a very specific type of technology or product, that has very consistent and well defined components - then buying 3D printing equipment can make complete sense however.
Hopefully this article has already given you some great ideas of the concepts behind the costs of 3D printing services. To sum up, here are some fundamentals to save on cost and get a better price with your 3D prints.
Techniques like topology optimisation and latticing are great for producing cheaper printed parts, as well as bringing weight to a minimum for performance reasons. When using SLS (powder) or SLA (resin) 3D printing, you should also consider hollowing out thick sections of your designs. As well as saving on material usage, which will bring the price of your order down, this will reduce the risk of warping. Be careful to leave one or more holes in your design to let that unfused powder, or uncured resin out though!
We've spoken before about how effective prototyping is all about knowing what question you're trying to answer. Significant cost-savings can be achieved by only 3D printing the parts of your design that need to be manufactured - in order to answer your question. This may be, for instance, only printing the interfacing sections of a given design, when what you need is know is - do the parts fit together well.
It can also be helpful to consider printing prototypes as scale models in some instances. As 3D printing costs are extremely sensitive to size, printing a model around 20% smaller can cut your 3D printing cost in half.
Often, the cheapest processes and materials are all that are needed. Our cheapest material, Recycled PLA, is still an excellent choice for a wide variety of prototyping needs. We have material data available on all of our materials, so browsing through these can be helpful if you have a particular requirement in mind.
