Generating savings in additive manufacturing thanks to variable working volume in the SLS 3D printer

Manufacturers of devices working in FDM technology are the leaders on the Polish 3D printer market. Although additive powder technologies are gaining more and more popularity, there are only two SLS printer manufacturers in Poland and the devices they offer are very different and in fact they reach completely different users.

Sonda SYS. is one of these manufacturers and offers large systems for production and industrial additive manufacturing. Interestingly, it is the only manufacturer on the world market whose devices have the option of changing the size / volume of the working chamber. The implemented variable chamber function allows the device to be used in an optimal way, both for larger and smaller prints (both in quantity and volume), and thus for both prototyping and mass production.

When we add to this the possibilities offered by the Selective Laser Sintering technology itself, i.e. the high strength of the details obtained and the almost complete absence of limitations in their geometry – we get a very flexible and highly universal production method.

According to the manufacturer’s opinion, many users at first find it difficult to understand what exactly the option of variable dimensions of the working chamber of the device is. And to dispel at the beginning the most common doubt: the device does not have two separate working chambers built in, but one that can be scaled. Which working field will be programmed as the basic one depends only on the user’s preferences. It can start with a smaller volume (265 x 265 x 310 mm) or larger (365 x 365 x 610 mm).

Scaling the dimensions of the working chamber, and thus setting the parameters of the SL02 device so as to use one and the other is possible thanks to the three-axis optical galvo. The Sonda SYS. SL02 probe is the only additive manufacturing device on the international market equipped with an optical system from Cambridge Technology (Novanta). Identical 3-axis systems are installed, among others in the guidance devices used in the US Army.

Therefore, to illustrate the possibilities offered by scaling the dimensions of the SL02 working area, a simulation (graphics below) was carried out on a simple cube model with dimensions of 50 x 50 x 50 mm and a volume of 125 cm3. In the first calculation, we assume that 15 such elements are needed, constituting a small prototype series.

When we have an SLS printer with a small working chamber, such a task is effective – in time and cost. The problem appears for owners of devices with larger working chambers, because the amount of powder needed to fill them and the time of making details are much larger / longer. Naturally, the option in such cases is to complement the large chamber with other elements – but we do not always have time to wait for them or we simply do not have such a need.

Meanwhile, the opposite situation may arise, when our need is to produce as many items as possible in the shortest possible time. When this task comes to the user using SLS with a working field from the smaller category – this process will probably need to be repeated several or several times to get the needed large number of elements. Using – it would seem just a little larger working volume, we can get up to 4/5 times of them once.

The graphic below shows the calculation for the SLS process of cuboids measuring 50 x 50 x 50 mm. By filling models with a smaller working space (265 x 265 x 310 mm), we are able to manufacture 80 such elements at once, and the whole process will take about 24 hours. Meanwhile, after scaling the work area to 365 x 365 x 610 mm, we get 396 elements in one process.

The process is naturally longer, but it still falls very favorably in time – it would take about 120 hours to obtain the same number of elements in a smaller chamber. In addition, the production of elements at once in a larger working space ensures less powder consumption (70 kg vs 85 kg at one batch), energy and significant savings on the working hours of employees operating the device and the production process.

Detailed information about the system can be obtained by contacting Sonda SYS. specialists.