Hard Enclosure for Purethermal Mini

cults3d

This enclosure was developed as a compact, modular, and cost effective means to provide reasonable protection for the Purethermal Mini enclosure sold by GroupGets. Each completed unit with heatsink cover takes approximately 1 hour to print using PETG and uses 1.47m of 1.75mm filament when printed at 100% scale. Also included is an example window module that allows for the use of LDPE film (aka grocery bags) as a cost effective way to protect the optics of the Lepton sensor module. To assemble and install the example window the beveled front ring fits over the smaller inner ring, and the window material should be stretched between the two pieces and pressed in with the inner ring. The excess material should be cut and the protruding section of the inner ring slides into the front window opening of the main enclosure. Note that the STL models are sized to exact dimensions, it is recommended that you rescale the parts before slicing to accomodate for your printer's presicion tolerances. This enclosure was designed for the Purethermal Mini MicroUSB model and has been tested and verified to work with this model. Since both models have the same PCB layout and dimensions this case should also work with the JST-SR Pro model with minimal or no modification, however this is not verified. The entire case is friction fit by design, no additional fasteners are needed to assemble the device. The inner and outer shells are seperated to allow for EMF shielding and/or a protective window to be added. The window opening has an inner diameter of 9mm when scaled to 100%. I added aluminum foil for EMF shielding between the 2 shells on mine and fused the halves of the outer shell together for use in harsher environments. Also included is a 11x11mm opening to allow for a heatsink of the same size to be used as the FLIR Lepton core as well as the STM32F4 MCU used on the Purethermal Mini series boards will get hot, which negatively impacts image noise especially when viewing low thermal contrast scenes. For maximum protection to the device there is a cover for the heatsink opening should you opt not to use a heatsink. Without the 11x11x5mm heatsink the camera reached ~42C when run at a room temperature of 22C indoors. With heatsink the camera reached about 34C and remained at that temperature for several hours. While it is not necessary in most cases the cooler temperatures wil reduce sensor noise and increase the longevity of the camera. List of included parts: Inner shell back (BodyBackInner.stl) Inner shell front (BodyFrontInner.stl) Outer shell back (BodyOuterBack.stl) Outer shell front (BodyOuterFront.stl) Heatsink opening cover (HeatsinkCover.stl) Example window outer bevel (ExampleWindowOuter.stl) Example window inner ring (ExampleWindowInner.stl) Lining between the inner and outer shells is optional, no window is needed but it is recommended to install one if you plan to use this in inclement weather or if the intended use might result in damage to the sensor or its optics. To assemble the enclosure, first add the lining of your choice to the outer shell back then press the inner shell back piece into it. The backs of both shells should face the same direction, and you can use the heatsink opening to verify that the inner shell is pressed all the way in. Then carefully press the PureThermal Mini board with an installed FLIR Lepton sensor into the form fitted holder on the inner back piece. If the board will not fit, you may need to sand the holder to fit. Also check to ensure the sides of the PCB are smooth, the snap points used in the manufacturing of these boards leave ridges on the side of the PCB that affect how it fits into any form fitting enclosure. Next assemble the front half in the same way as the back half, adding the lining to the outer front shell and pressing the inner front shell into it. Then assemble the two halves. Take care not to damage the shutter assembly of the FLIR Lepton, as they are much more fragile than the rest of the device and they are annoying to use without a shutter (also the PureThermal Mini with stock firmware does not support shutterless operation). Though I have found this enclosure to be quite robust in my own use, I am not responsible for any loss or damage of any kind resulting from or related to the use of this enclosure. Updated 0725 EST, 12 Feb 2022: Added assembly instructions, updated instructions included in downloadable zip file to include the same instructions. Updated 1543 EST 21 Feb 2022: Added photos of the printed pieces and a photo of my own personal example after ~1 year of use