Gas nozzle hot end

NB: The following tutorial need the use of power tools (drill press) in some non-standard way. There will also be dangerous metallic dust filling the room. Also the tools and parts you are machining can easily break, projecting pieces of all dimensions and at high speed. Please wear heavy gloves, anti-dust mask and goggles at all time when using the tools. Some noise protection will be good too. I know it's not confortable working in that way, but you really don't want to loose a finger or an eye, or breathing some alluminium and brass, just to make an hot end.

Gas nozzles come in many different shapes but they all have 1 thing in common: they are really cheap. I paid 6€ for a set of 5. After looking to various models i found the better suited are the "gpl nozzles", with 8mm screw and round body. The inside diameter is 5mm. Don't take the methane nozzles because they have bigger holes. With the smallest gpl nozzle the pla filament i get is something between 0.45 and 0.5 mm which for me is more than satisfying.

My suggestion is to make all the machining with the biggest hole nozzle, so any error in the process won't damage the little hole one, which is the most useful.

To be able to connect the nozzle to the other parts of our hot end we must use the die tool. The screw thread already present on the nozzle is not compatible with usual m8 bolts and nuts, so all become easier if we remake the thread. I used a die of size 8mm x 1.25.

Now we want to make the thread on the long side of the nozzle, to be able to mount the heater on it. We start by reducing the external diameter from 10mm to little more than 8mm. I didn't want to damage the thread mounting the nozzle directly on the drill press, so i used an m8 bolt with cutted head and a long nut.

NB:I made the photo with the drill press turned off. This is why i'm not wearing gloves. Don't do it without gloves!