HDB BTO Window Cockspur Wedge

thingiverse

Some HDB BTO casement windows feature a nylon plastic wedge for the handle/lever to grip and securely close the window against the gaskets. The lever is called the cockspur design and this file is designed specifically for printing that plastic wedge. Check out this video: https://imgur.com/gallery/mKH3CQO I chose not to redesign the original, opting instead to replicate it as closely as possible, despite its numerous flaws. By design, it's inherently weak, which is why a replacement is necessary. It relies on friction and has small, fragile stems that are critical for strength, but unfortunately, they're also prone to damage. If you print with PLA like I did, the part will be even more susceptible to wear and tear. Nylon is the original material used, although ABS is a suitable alternative - just be sure to scale up by 100.5% or so to compensate for shrinkage, as this part is extremely sensitive to tolerances due to its press-fit design. You can print test.stl, a modified version of the part that's been shaved down to assess your printer's tolerance before moving on to the actual part. To achieve optimal results, print the wedge along the edge, just like in the STL preview. This ensures maximum strength for the stems and helps prevent damage. Be sure to add supports for those critical stems as well. A 0.2mm layer height is sufficient, while at least four shells are recommended. Given the high stresses this part will experience over time, I recommend printing it with maximum infill settings.