PRUSA Research presents the new MK3S + 3.12-BETA firmware with thermal protection and blob detection

PRUSA Research – the largest European manufacturer of amateur 3D printers, has announced a new beta firmware for its FDM / FFF 3D printers, which takes a more sophisticated approach to managing the temperature of 3D prints. The new software is aimed only at MK3 / S / + 3D printers.

Managing temperatures in amateur or desktop-class 3D printers has always been a problem and was the main risk of damage or in extreme cases – a fire of the device. At the same time, nowadays it is important to save electricity (especially in domestic and non-commercial conditions), therefore greater control over temperatures is equally important.

Temperature control in 3D printers is very simple – the sensor (thermistor) reads the temperature of the head or the heatbed and, depending on its level, either heats up or cuts off the additional heating of a given component. When the temperature sensor fails, it informs the controllers that the set temperature has not been reached and the component, such as the print head, starts to heat up to higher and higher temperatures, overheating the material and, in the long run, causing a fire. Unfortunately, it was common in old models of very cheap Chinese 3D printers from the Anet or Tronxy series, where the sensors and their wiring were faulty or were mechanically damaged during operation. For some time now, almost all amateur-grade 3D printers have included a firmware routine to handle thermal instability.

PRUSA in the latest version of its firmware solves it in yet another, more advanced way:

The new model-based thermal protection is designed to detect unexpected heating problems of any kind and stop it quickly (within 10-12 seconds) to avoid potential damage to the printer. This includes cabling problems, a malfunctioning heater block, thermistor faults and also external influences (drafts, blobs forming on the extruder, etc.).

All of this is based on an internal hotend simulation, meaning the firmware is constantly checking that the thermistor readings match a specific pattern in the thermal model. If something does not seem right, the printer responds within seconds and displays a THERMAL ANOMALY warning which disappears if readings return to expected values ​​within 5 seconds. If the anomaly remains, the 3D printer turns off the heating and turns on a warning sound to alert the user. In other words, it is a great addition to the already existing thermal protections that are used in the printer from scratch.

The main change is that the temperature anomaly detection process allows the 3D printer operator to determine what is causing the errors. PRUSA Research has published a very detailed explanation of how the new firmware works in practice, including graphs and visualizations.

Another change is the constant monitoring of the heat block and comparing the readings with the internal thermal model. As a result, the 3D printer is able to quickly detect cooling anomalies. When the printout detaches from the table, it will stick to the print head, creating the so-called blob of material around, this can also trigger a THERMAL ANOMALY error. If the situation persists for a few seconds, heating will be turned off and printing will stop. In this way, the firmware can stop the 3D printer before a major failure occurs.

At the same time, PRUSA points out:

Of course, that doesn’t mean blobs will be completely eliminated from now on. Rather, we are talking about being able to detect them quickly as soon as they start growing – which usually happens early enough that it saves us a lot of work removing the plastic monster surrounding the hotend.

Firmware is available for download on GitHub. ATTENTION! As it is still a beta version, it is recommended to be used by users with adequate experience in working with Prussian 3D printers.

Source: www.prusa3d.com