TITLE: 3D Printing Case for LED Controller
AUTHORS: Jakub Nedbal

[DESCRIPTION]
<div class = "text-blocks"><div class = "text-block">The electronics control circuit for the illuminated orbital shaker should be housed in a case to protect it from damage by short-circuit, but also to minimize injury by electrical current and fire hazard.</div><div class = "text-block"><span style = "font-weight:bold;">This document is part of the Illuminated Orbital Shaker for Microalgae Culture project:</span></div><div class = "text-block"><ul style = "list-style-type:disc;"><li style = "counter-reset:ol0;list-style-type:disc;">​Procuring Parts for Algal Shaker​</li><li style = "counter-reset:ol0;list-style-type:disc;">Assembling LED Controller Electronics</li><li style = "counter-reset:ol0;list-style-type:disc;"><span>​3D Printing Case for LED Controller </span><span style = "font-style:italic;">(this document)</span><span></span></li><li style = "counter-reset:ol0;list-style-type:disc;">​Assembling Cooled LED Illuminator​</li><li style = "counter-reset:ol0;list-style-type:disc;">​Cutting and Drilling Clear Acrylic Sheet​</li><li style = "counter-reset:ol0;list-style-type:disc;">​Assembling Algal Shaker</li></ul></div><div class = "text-block">​</div></div>

[STEPS]
?. The electronics circuit has been designed in KiCAD. KiCAD PCB files can be opened in FreeCAD. This in turn allows exporting the 3D render of the PCB into an industry-standard STEP file format. The STEP file can then be imported into Onshape, which is a 3D CAD tool. Onshape was then used to create a 3D model of a case to hold the electronics printed circuit boards with all its components. The case consists of two parts, the Top and the Bottom, which are fixed together by screws during the final assembly. The model of the case with the embedded electronics circuit is openly available on the LED regulator case project page.3D printing, whether done in-house or outsourced, requires STL files to work from. The STL files can be found on the LED regulator case project page in a subfolder named STL Files, as shown in the screenshot below:Use the two downloaded files LEDregulator - Box Top.stl and LEDregulator - BoxBottom.stl to 3D print the two case parts.
?. There is no general instruction on how to run a 3D printer. We used an in-house Stratasys uPrint SE Plus fused deposition modelling printer with printed support according to manufacturers instructions. The support material was subsequently dissolved by immersing the 3D printed parts in a warm hydrogen peroxide bath.This step is potentially hazardous. All local regulations and procedures were observed and personal protection equipment was used.Finally, the two parts were thoroughly washed with copious amounts of water and dried prior to further processing.
?. The Top part of the case is printed with four blind holes in each corner, highlighted by the black arrows in the image below:​Use an M3 thread tap to create M3 threaded holes in each corner. In areas, where Imperial thread sizes are in use, swap the M3 threads for locally common #4-40 UNC threads instead. They have similar diameter and due to their courser thread spacing, they are better suited for soft materials like plastic.The thread is typically created in three steps using three thread taps with progressively deeper cutting threads. Start with the shallowest thread tap and finish with the deepest thread tap. Some tap manufacturers help identifying the order of taps by the number of engraved lines (see image below). First comes a tap with one line, followed by a tap with two lines, and finished with a tap with no lines. Use a tap wrench to do the thread tapping. An illustrative image of an M3 thread tap set and a tap wrench are in the image below:​
?. The document Assembling LED Controller Electronics explains how the electronics is assembled onto a printed circuit board (PCB). The PCB fits into the printed 3D case. The case is held together by four M3×10 mm counter sunk screws. Where imperial threads are common, four #4-40 UNC 3/8"-long countersunk screws should be used instead. The assembly is really trivial and only takes a screwdriver or an Allen key, depending on which screw head type is available. The image below should be sufficient to explain the assembly procedure:The assembled LED Controller is shown as 3D render in the image below:
?. This document described how to obtain STL files to print a case for the LED regulator electronics circuit. It explained the assembly steps. Once the electronics is inside the case, it is ready for use with the Cooled LED Illuminator, described in the next protocol.
?. ​LED regulator case: Onshape project with STL files available for download for 3D printing the case for the LED regulator electronics.
?. This document is part of the Illuminated Orbital Shaker for Microalgae Culture project:​Procuring Parts for Algal ShakerAssembling LED Controller Electronics​3D Printing Case for LED Controller (this document)​Assembling Cooled LED Illuminator​​Cutting and Drilling Clear Acrylic Sheet ​​Assembling Algal Shaker​