This thing has moved to Youmagine: https://www.youmagine.com/designs/ultimaker-bowden-pop-stop This little gadget is for the Ultimaker v1 Hot End and does these things for you: The Pop-Stop forms a solid barrier that fits inside the wooden head block. A short length of tube provides a filament path from the Pop-Stop to the brass nozzle (inside the PEEK part). The Pop-Stop prevents the tube from separating from the brass, and through the four long screws, it allows some pressure adjustment so that you can be assured a good fit between tube and brass without ever getting leakage that causes the traditional tube plugging/slipping/popping problems. The main length of Bowden (from the extruder) is then attached to the head and the Pop-Stop either by use of the standard white clamp and blue clip, or by an "Owen Clamp" (which is printable). It's possible to use e-clips or any other type of clamping solution - the good news is that most of the back-pressure force is absorbed by the Pop-Stop, so the clamp doesn't have to do very much work. Even if the clamp isn't very good and lets the tube slip a little during a long print, you won't get a plug and your print won't fail.I printed this part in 0.2mm layers (ie. "standard" quality). High quality may work better if you can do it. It doesn't take long to print, so you won't have to wait long for it. I tend to use the "Joris" feature in Cura, but it's probably be fine without it (and probably fine in other slicing software). You need to clamp the bowden to the head. I personally use an "Owen Clamp" (found here: http://www.thingiverse.com/thing:11864 ), but you can use the standard white clamp and blue horseshoe clip (see notes below though), or any other clamping solution you happen to have. Once it'a all printed: Clamps I'm using the Owen Clamp, because I already have one and I found the white clamp didn't quite fit in the top of my wooden block. It fits in the hole, but is too close to the walls of the block to function correctly. If your block is the same, then you can solve the problem by cutting a small amount off the wooden walls of the block. Caveat maker ;-) It's also possible to use any other clamping solution you happen to have. "Eclips" seem to be fairly common, and will work (same caveats as the white clip above though). Filament Threading I found the first time to be quite a challenge! I've found that not tightening the clamp makes it easier to push the filament through (tighten the clamp once it's threaded though!). You may also find that trimming the tip of the filament into a point helps quite a bit. Once you've done it once (and tightened your clamp) then it's easy after that. So what's all this done? Things left to do in the Pop-Stop