3D printing can be an effective tool for demonstrating how objects will look, checking how they will connect or fit together with other objects, testing assembly sequences and simply trying out the handling or ergonomics of a new design. However, in many cases 3D printing becomes a gimmick or a source of throw-away items handed out as a promotional tool or acting as a conveyor belt of useless objects downloaded and printed from online platforms. This problem is made worse when printing at small scale where the object becomes no more than a cheap novelty.
Presented below are a selection of example 3D prints that were used in practical ways as part of an engineering design workflow. These are positive uses of the technology that helped with visualising how an object would be assembled or interact with other assets. Time was taken to produce the models, often at large scale (actual size), meaning they have lasting value and perform better as test objects.
Some background
The dividing line between professional and hobby 3D printing can be very blurred, given the competitive prices of ever-improving machines that are easy to operate. Often the machines being purchased for professional use in print farms and warehouses are the very same machines being setup in people’s garages, sheds or homes.
As accessibility to the technology spreads, finding specific and useful situations for 3D printing is key, focussing on where it adds value to a product or project development. Rather than producing large numbers of prints and therefore inevitable waste, it is better to use 3D printing as an aid to design where tangible benefits can be found. Presented below are some examples of this where 3D printing has been used, in a limited way, to progress or promote a concept or design and has helped to identify potential issues, furthering the planning procedure.
In the first instance, it should be known for those who have not experienced 3D printing that the process is very time consuming. Certainly in terms of the time that it takes to print the objects. This is more so when it comes to printing at full-size or for objects any bigger than would fit in the palm of your hand. It is worth printing at larger scales, or at full-size if applicable, as the resultant object will offer far more insight and value when used in discussions and design reviews. It is common for larger prints, not to take hours to print but instead to take days. If your intended assembly is to be made from a number of these larger prints, then the whole object can take weeks to create. The cost in print time is mitigated by using multiple printers, but the combined time is considerable none the less.
Although completed prints can be produced in high quality, meaning finer degrees of movement of the print head usually on the Z axis resulting in a smoother appearance (at a cost of longer print times) hand finishing will be required to create a better surface. This is most noticeable when spraying a 3D print to achieve a certain colour or glossy finish. On lower quality prints, or those that have not been sanded, paint tends to highlight the poor surface of 3D prints. This issue is improved with modern machines, or by avoiding needing paint by selecting plastic of the intended colour as a start. Although a glossy painted look is only achievable with some manual labour.
Please note that for each of the examples highlighted here that the process employed is via filament printing known as FDM (Fused Deposit Modelling) which is an additive manufacturing process where plastic is extruded from a heated nozzle to build objects over a number of fine layers. This method is best suited to the creation of larger scale objects.
Design iteration and prototyping
This example shows an iteration of a riser pull-head design that was used to help make decisions on the function of the swivel component and to improve understanding of the operation and assembly offshore.
A difference can be seen between the design below and the version above, moving the location of the swivel amongst other changes. The first iteration was smoothed and sprayed to portray a metallic finish, but in the real pull-head the various components would be painted yellow and red.
Also note the use of actual nuts and bolts which make a huge difference to the visual impact and feel of testing the design as a 3D print. This also allows for checking access to the hardware, even in a scaled form – for example using bolt tensioners and other tools.
Visualisation (rigging and lifting)
These examples show how 3D printed representations of equipment, assets and structures can be used together to help visualise potential lifting operations. Especially where there are great difficulties in planning or developing CAD drawings for such arrangements, a 3D print at scale can immediately reveal potential issues or confirm basic assumptions about the proposed movements.
In fact, very simple models can reveal much of the setup and help communicate problems with Project Teams for further development.
In these cases, finishing and spraying are not required as the model itself is the focus and need not entail large amounts of work.
Promotional
The advantage of creating full-size 3D prints is that they represent the actual object in an easy to move and easy to display way. Whereas in the ‘real’ version of an object such as this the solid metal design would make it near impossible to transport and present at trade shows or conferences (without great cost). A lightweight 3D print can be lifted and moved by hand while still fully representing the actual item.
Following much sanding and painting the 3D print has a very presentable appearance where some weathering effects can be applied to metallic surfaces to give a realistic look.
In general, 3D printing is an excellent way of producing a physical copy or representation of a proposed design, but people may not be aware of the time required to not only print the object but also the time required to bring the print up to a quality finish. Objects at a good scale will routinely cost dozens or hundreds of hours to produce, in machine time and manual labour. Scale and speed of production is improved with print farms, but this scenario is more focused on retail and business-to-customer rather than being part of a project development where critical items can benefit from being realised as a tangible model. 3D printing is at its best when helping to perform clash checks, confirm assembly procedures, and informing the design of products and tools as they develop over the course of a project.
Return here to the Perspective website in the future or check out the LinkedIn page for updates and information on new projects where 3D printing plays a key role.