Simpler hot-end

thingiverse

I've replicated Wildseyed Simple Hot End by jcabrer for my Simpler repstrap, but with adjustments due to living in Metric land along with the ROW (rest of the world). I discovered a way to use the unused M6 thread on the MIG tip advantageously, making it easily exchangeable. This design also ensures easier and more precise alignment of the PTFE fitting than Wildseyed allowed, while offering a bonus double seal on the PTFE rod. Additionally, using the gas connector nipple provides a flat face for the heater, simplifying nichrome work and giving you the choice of heater technology. Please note that this hot end is still a work in progress, with instructions to be updated as needed. Here are the steps to build it: 1) Push the adapter into the drill press chuck tip-first, tighten slightly, and lower the drill press while clamping the adapter on its base in the drill press vice. Release the chuck from the adapter and insert an 8mm drill bit, then carefully increase the inner diameter of the adapter shaft all the way through. Remove the adapter from the drill press and use a hacksaw to cut it at the middle of the narrow section, filing for neatness. 2) Lightly clamp the MIG welding tip in the drill press chuck, using its flat faces on the tip to secure it in the drill press vice. Insert a 3.2mm drill bit and, using cutting oil, cut exactly 25mm into the back of the MIG tip. Ensure metal filings and cutting oil are removed. 3) Clamp a piece of scrap wood in the drill press vice, drill about 15mm with a 3.2mm drill bit, attach the PTFE rod to the drill press chuck, and drill a 3.2mm hole through it using a long nose plier while holding the stationary drill bit. Then, use a 4.5mm drill bit to drill 8mm into the 3.2mm hole. Reduce the end with the 4.5mm hole to 12mm or less for easy turning. 4) Assemble the parts by tapping the MIG tip into the adapter, inserting the 3.2mm drill bit into the back of the MIG tip as a guide pin, and turning the PTFE rod onto the threaded sections of the adapter and the MIG tip. Check alignment. 5) Optional: Countersink the back end of the 3.2mm hole in the PTFE for easier filament insertion. Remember that this hot end is a work in progress and instructions will be updated accordingly.