Thermwood Corporation, which calls Indiana home and is the oldest CNC machine manufacturing company in business, has good news: they’ve added real-time thermographic imaging as a standard feature on their LSAM (Large Scale Additive Manufacturing) systems. We introduced you to the LSAM recently: it’s a refined version of the company’s double gantry machine concept. The giant 3D printer has a build envelope of ten feet wide, five feet high, and anywhere from ten to one hundred feet long. The addition of the new thermographic imaging will make it a lot easier to adjust and control the whole printing process, which will create the best printed structures as a result.
If you want high-quality, void-free large-scale 3D prints, there is a pretty narrow range of temperatures for each material where printing is ideal. You need to be able to control the temperature of the print surface throughout the printing process: the previous layer must be cool enough to support the new layer without any distortion, but also warm enough to completely fuse with the new layer. The intention is to constantly keep operating within that range of ideal temperatures, which can be easier said than done. Thermwood’s new thermographic imaging system shows the operator a full color thermal image of the part at the same time it’s being 3D printed, which is enormously helpful while trying to stay within that optimal temperature range.
With their new system, a green color has been assigned to that perfect temperature range for the material to be printed with the highest quality. The thermal image is displayed on the control screen in a window that’s both movable and resizable. Ideally, you want to print continuously on green, so you know you’re in the proper range. Once the print temperatures are known and that ideal green can be pinpointed, Thermwood’s printhead control makes it simple to adjust the parameters, in order to get the ideal print surface temperature. For instance, if the part being printed starts to get too hot, you have two options: you can reduce the print speed, or turn up the fan cooling system. The same applies if the print is too cool: you can either increase the speed or reduce the cooling.
Before now, using low output printheads to print bigger parts created a different type of thermal problem: slow print speeds would prevent the printhead from going back to a point before it cooled too much, so you couldn’t achieve the correct layer to layer bond in the print. Thermwood’s high output printheads (the biggest one can print up to 500 lbs. an hour) are another key component in making sure large parts come out with high print quality. The imaging system provides temperature guidance, which helps the operator consistently accomplish the best results. This way, they can make very high quality thermoplastic composite parts with no worries about print quality.
Thermwood’s new thermographic camera can be mounted in three different locations on the LSAM system.
- It can be mounted inside the machine from a fixed position on a stand, so it’s looking directly at the part
- It can be mounted inside the print gantry, which works well for large parts that are too big to view as a single image
- It can be mounted to the printhead itself, for special applications
The image output from the camera is integrated with Thermwood’s print gantry CNC control, and the full color temperature image (remember, you want it to be green the whole time) is displayed on a resizable window on the control display. A touchscreen lets the operator touch any point on the image and read the exact temperature of the selected point.
Using their new thermographic technology, Thermwood now has the ability to produce large tools with the LSAM that are solid and void-free enough to maintain a vacuum, without any necessary surface coating or sealing. This simplifies production and allows for accurate surface machining, without having to worry about any nasty distortions caused by variations in the thickness of a coating.
To see their new thermographic camera in action, check out this video from Thermwood’s blog page:
Discuss in the Thermwood forum at 3DPB.com.