The J-Head Lite V2 Ultimate Economy RepRap 3D Printer Hot End

thingiverse

This is the first and only $20 fully assembled hot end. The V2 is the first commercially viable hot end that people can actually afford. It combines the holder of the J-Head, the heat sink of the Arcol, and the hot end of the MK7.We're pushing the envelope of design and thermodynamics to bring 3D printing mainstream. See it in action:http://youtu.be/jkiKdGfhyIw Specifically designed for 1.75mm filament, This design extrudes PLA and ABS, as well as many other plastics. The extruder can heat up to 250C. It sports the Honeywell 100K ohm thermistor for accurate temperature readings. Unlike all metal hot ends, this design uses passive cooling. It does not require a fan. Made out of: 1/2" PTFE rod (McMaster-Carr # 8803K14) PTFE wire sleeving (McMaster-Carr # 5335K13) PTFE barrel sleeving (McMaster-Carr # 5335K18) PTFE heat shrink tubing (McMaster-Carr #75665K56) Brass nozzle (McMaster-Carr # 8952K33) Ceramic insulation (Mcmaster-Carr # 87575K85) M6x1 stainless steal barrel (McMaster-Carr # 90024A461) Aluminum heater block (Clinton Aluminum .375"X.5" 6061) Laser cut oak mounting plate (Lowes 1/4" Oak) Vishay 6.8ohm resistor (Digikey # RWMA-6.8CT-ND) Honeywell 100k thermistor (Digikey # 480-3135-ND) Heat Resistant Wiring (skygeek.com # M22759/16-22-9) Copper Heat Sink (Zoro # G1445893) Brass nut (Zoro # G3497794) Start the revolution: http://stores.ebay.com/ohpakron Instructions Instructions: http://youtu.be/NCn7svBsEjs Things needed: Kapton tape PTFE tape Permatex anti-seize lubricant -optional Heat sink compound -optional Vice grip Wrench Wire stripper Scissors Solder Soldering iron Number 36 drill bit 6mm drill bit 10mm socket wrench bit, reamed to at least 6mm All are available at your local hardware store or Radio Shack, except Kapton tape, which can be found from various online sources: Grainger, McMaster-Carr, Ebay, etc. This process may take an hour or longer. These instructions are highly complicated. The risk of burning and/or electrocuting yourself is very high. Wear appropriate safety gloves while handling hot metal and live wires. I encourage novice users to not attempt this assembly. Prep: Soak the heater block, the steel tube, and the nozzle in acetone or laquer thinner to remove residual cutting oil and/or particulates, which may jam the nozzle. -optional Put some anti-seize lubricant on the nozzle threads and screw it into the block. Make sure it's tight. Take the small PTFE tubing and cut it into 4 parts. Put it on the leads of the thermistor and resistor. Coat the resistor with heat sink compound and insert the thermistor and resistor into the heater block. Cut the "Tefzel" wire into 4 equal parts and strip them. Solder the leads of the resistor and thermistor to the wires and insulate the joint with Kapton tape. Wrap the block with the ceramic insulation and secure with Kapton tape. Coat about 1/3 from the bottom of the steel barrel with a 1/4" worth of heat sink compound. Screw the brass nut onto the middle of the steel barrel. Note: The threads on the barrel may be rough due to the machining process. If you are unable to screw on the nut, please contact the manufacturer. Wrap both ends of the barrel with PTFE tape; 1/4" at the bottom, 1/2" on the top. Put the heat sink onto the barrel. Screw the barrel into the heater block. Note: The end of the barrel that's countersunk is the top. Screw in the flat side. Attach the wires of the hot end to your controller board. Heat the hot end to 255C (smoke is normal). Take a pair of vice grips and clamp it to the top of the barrel. Take a wrench and screw the nozzle and the barrel together. Take a 10mm socket wrench bit and tighten the brass nut down onto the heat sink. Thread the PTFE holder onto the barrel hand tight. Wait 3 minutes Note: This part is delicate. It's very easy to strip the threads on the PTFE, because it's soft material. Slowly tighten the PTFE holder onto the barrel hand tight. Do not over tighten. Do not under tighten. Turn off the heat and let cool ~15 mins. Take a #36 drill bit and ream out the PTFE holder. Note: I find it's best to use vice grips and clamp the drill bit to hand ream the hole. I'm looking for alternatives to this step, but that's the best I've got for know. Insert the PTFE liner all the way down into the hole and trim the top with a very sharp razor blade. Take the wood mount and carefully insert it into the groove mount; The wood can break. These PID settings are a good place to start: define PID_INTEGRAL_DRIVE_MAX 10 define PID_PGAIN 2560 define PID_IGAIN 64 define PID_DGAIN 4096 Also you need to change the thermistor settings in your firmware: define TEMP_SENSOR_0 1 to... define TEMP_SENSOR_0 7 You may find that your fan is over-cooling the hot end. If you experience this problem, reduce the fan speed, or direct it away from the hot end. Or, just don't use one.