LED Spotlight Diffuser

thingiverse

This is a diffuser for Gemmy-style three-LED spotlights that are often sold by Home Depot, Lowe's, Kroger, and other retailers. These spotlights probably won't work with fire-and-ice or similar products. The diffuser itself is the white circle in the photos. It makes the light less focused and reduces brightness/glare, which is beneficial when the light is directed at your porch. The white part around the edge of the diffuser is a test print for another part that hasn't been completed yet. Choosing a Model ---------------- The original model has a face thickness of 0.4mm. After testing, this thickness blocks enough light to be indistinguishable beyond 3-4 feet in ambient lighting conditions like those found in my yard. However, if your setup is darker, it might work better. This thickness works well when printed in natural PLA but might be a bit low - the light still casts shadows from props 6+ feet away onto walls twice that distance. To address this issue, I've created additional versions of the diffuser with different face thicknesses and hole patterns. The 0.3mm face thickness version is intended for White PLA, while the 0.5 and 0.6mm versions are designed for natural PLA. Printing the Diffuser ------------------- Regardless of the model chosen, it's essential to print the diffuser at a layer height that adds up to exactly the listed number. For example, the 0.3mm model can be printed with 0.1mm layers and a 0.2mm initial layer or with all layers at either 0.1mm or 0.15mm. Any combination of these heights can add up to 0.3mm. The reason for this requirement is that when your layer height(s) don't evenly add up to the thickness of the face, the slicer will be forced to print a thinner part or a thicker one, depending on its slicing algorithm's priorities in the Z axis. Specifying a single layer height tells the slicer it can only print a face with that exact thickness. Material and Part Thickness ----------------------------- While material choice and plastic thickness are significant factors affecting diffusion, they're not the only ones. FDM printing produces parts with inevitable voids caused by filament curvature and uneven layer texture. This is why transparent filaments don't produce completely transparent parts. The consequences of these factors include varying results due to the exact number of layers, fill patterns used by the slicer, under/over extrusion, and nozzle size. However, material and part thickness are among the more obvious and easily changed factors. Experimenting with Concentric Infill ----------------------------------- To provide a more even diffusion, somewhat like a Fresnel lens, I'm currently experimenting with concentric infill in Slic3r Prusa edition. To achieve this, set Top and Bottom horizontal shell to no more than 1. If you go above this number, the extra horizontal shells will not respect either pattern setting on the Infill options page and will use a rectilinear pattern instead.