Silicone insulation sock for Raise3D V2 hotend

thingiverse

Introduction This reusable mold is designed for two-part RTV silicone casting compounds and putties, creating a heat-insulating silicone sock that covers the heat block. The model includes separate files for both left and right extruder hotends. I have not compared its thermal performance to other solutions, but it certainly looks impressive! This is version 1 of this design, so please feel free to suggest improvements and provide feedback. I created the model in OnShape, a great online CAD package that you can view and even export for free with an account. I also uploaded Solidworks part files, including parts and an assembly for the hotend itself. If you need another format, just let me know. Edit version 1.1: Created an air gap between the silicone sock and the heat block. Previously, the silicone was 2mm thick; now it's 1mm thick with standoffs that create a 1mm air gap. The sock is slightly more difficult to release from the mold, but it should insulate well. Filleted the bottom of the sock. OnShape link V1.0: https://cad.onshape.com/documents/755775ac5ac5e8ceb9784b7d/w/7a709f9d2c30f75e0e5a75b8/e/5cf270a76a18d9ef2997f353 OnShape link V1.1: https://cad.onshape.com/documents/755775ac5ac5e8ceb9784b7d/w/8876288e3425e86ff16e77c3/e/19da563b0818a4e38b896471 Versions/Future plans: V1.0: Initial release --> V1.1: Create an air gap between the silicone and heat block for better insulation. V1.2: Improve the mold design to make extraction easier. Instructions Print the mold using any rigid material, but print it fairly sturdy with 3 shells and 25-50% infill recommended. If you're using pourable silicone, maybe a flexible filament would work; I haven't tried it. Get some high-temperature RTV silicone casting compound or putty. I have tried two types: TAP Plastics platinum cure (translucent white, 260°C), and Castaldo Quick-Sil putty (green, 315°C). The TAP Plastics stuff works well but is a bit expensive. The Quick-Sil putty is available through McMaster and Amazon; it can be gotten in small quantities, cures super fast, and is rated for higher temperatures. However, it is infused with mineral oil, which will smoke a bit when heated until it burns out. Make sure the two mold parts fit together easily. If the little pillar on the top part melted a bit during printing or something, just file/sand it until it fits loosely; it's only there to index the pieces when mating. The top piece should slide down far enough that the pillar is flush with the small hole on the bottom of the bottom piece. The rounds on the ends of the top piece should be touching the walls of the bottom piece. Prepare your silicone. You'll need about 15 grams for this project. Let it cure for the full curing time; I heated my printer's build plate to 50C and set the mold on top of it to help it cure. Extract the silicone using a hobby knife or pliers, depending on what you used as release agent. Clean up the silicone by removing any minor flashing around the hole for the nozzle. Tweezers work well for this task. Put the silicone sock on your hotend! The silicone sock splits in the back and top, so you will be able to slide it over the heater block without removing anything. Removing the side cooling fan will make it easier. You're done!