On discussion with Vik and how he wanted to setup a place that sells RepRap kits in, and seeing as I needed extruder bits for my RepStrap, I set forth to use the bits from the RepRap Subversion. There is a big problem with the drawings of the extruder bits, from ease of changing nozzles to a general lack of missing dimensions and also attempting to remove some known problems with them. So here are all the refined versions of them, with two types of nozzles. The two types are, Fully machined and have the NT extension (NT means no text, as the first version had text on it, but it became way too expensive to produce, hence the NT version) Domed nut version.The domed nut version is very cost effective, and can be purchased virtually anywhere, i've only included the NT version for people to play with if they want, as most people will wan the domed nut version.You may notice a 0.2mm dimension there, and this was once a proposed future extrusion size. The drill its that need to be bought for it have a short drillable depth of less than 2mm, thus a domed nut version is the way to go for this size of extrusion.The domed nut nozzle is also cheaper to produce than the MakerBot nozzle.The parts are designed to make use of local CNC or machining companies or businesses, hence the need for more dimensions.Enjoy!The parts go together as you\'d normally expect, however, the heater barrel needs to be as tight as possible in the thermal barrierFor this you'll need a 12mm spanner. 2 x M6 nuts, do not use the nozzles at this stage. A 10mm spanner for the M6 nuts M6 flat washer Zip tieScrew the heater barrel into the thermal barrier by hand, Screw on an M6 nut and screw it down near the bottom, leaving about a 2mm gap from the thermal barrier, Screw the second M6 nut down to the first, Using both spanners tighten the barrel into the thermal barrier, by using the second M6 nut and the thermal barrier.Once those two bits are tightened, loosen the nuts on the thermal barrier by screwing DOWN further the first M6 nut closest to the thermal barrier, if you left enough gap this will be easy, then UNSCREW the second nut off the barrel, then the first nut.Put on an M6 flat washer onto the barrel. Screw on a nozzle, tighten if you can to about 1Nm of torque <- IMPORTANT don't over tighten nozzle.Then the rest of the assembly is as per normal, with nichrome wire and thermistor/thermocouple, using your choice of Kapton tape and/or fire cementFinally use a zip tie to keep all those wires from flying about, use the flats used in assembly of the thermal barrier to secure them down.