Assembling a Hot End and Wade's Extruder
27 February, 2012
Wondering which Barrel, PTFE Rod and Nozzle to use?The size of the hole in the PTFE Rod and Brass Barrel needs to match the filament you intend to use. If you try to use 1.75mm filament in a 3mm hole, it can buckle and twist and cause jamming which is can be frustrating to remove. 1.75mm is being used more and more as it can give better print output. Each time the extruder nozzle needs to stop at the end of one run and jump across to print a layer on another position, it can leave a "spider web", a thin thread of plastic. This becomes messy over time, so the software tells the stepper motor to reverse a couple of steps to stop the plastic coming out justs before the end of the run, and then step it forward again just before the next run starts. This will be more accurate with a 1.75mm filament. 3mm filament is thicker and so less flexible when being unrolled into your machine.
A smaller nozzle (such as 0.34mm) gives a more accurate printout and can allow smaller layer heights, but if you want lots of plastic to come out, because you are printing larger objects (at least the full size of your print bed) or want to do a lot of printing, then try a 0.5mm nozzle
Assembling a Hot End
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 | Step 1: Take a 100K Thermistor and a heat resistor and solder wires to each end. You should use a heavier gauge wire than that shown for the heat resistor, such as speaker wire as it has to carry lots of current. | ||||||||
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Step 2: Completely cover the leads and joins with kapton tape, but do not cover the body of the part. | ||||||||
Step 3: Prepare the Aluminium Heater Block, Nozzle, Brass Barrel and PTFE Tube.The PTFE Tube should be bored out with a 5mm drill about 20mm deep into one end, then Tapped with an M6 tap to accept the barrel. This step may already have been done for you depending on whether you bought just the part, verses a kit from us. |
Step 4: Screw the Barrel into the PTFE Tube, then spin the Aluminium Block onto the Barrel, and put the Nozzle onto the Barrel.Then spin the heater block back down the barrel until it is tight against the Aluminium Block | ||||||||
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Step 5:Smear each part with Heat Grease - it helps to make sure the part is in complete thermal contact with the Aluminium Block. Slide the Heat Resistor and Thermistor into the Aluminium Block. Some people then pour epoxy resin into the holes from each side to hold them in place. We suggest using Kapton tape to wrap around the short sides of the block, at least until it is all tested and working. Congratulations! your Hot End with PTFE thermal barrier is now ready to attach to the Extruder of your choice. | ||||||||
Assembling a Wade's Extruder
These instructions will also work for other similar extruders such as Greg's extruder. The principle of the sprung shaft and bearings used to pinch the filament is also used in Adrian's Extruder and the mini universal extruder.
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 | Step 1: Push the large plastic idler gear onto the M8 Hobbed Bolt | |||
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Step 2: Push the short shaft into the plastic housing, inserting the 608 bearing in the centre. | |||
 | Step 3: Push 2 608 bearings into the extruder body - on each side. | |||
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Step 4: Assemble washers and pen springs onto 45mm long M3 bolts. | |||
 | Step 5: Thread bolts through the assembled Pressure Plate and Extruder Body and add nuts. | |||
 | Step 6: At this stage it is a good idea to add the M5 Extruder Mounting bolts, washers and nuts. The later become obscured by the stepper motor and pressure plate. | |||
 | Step 7: Mount the stepper motor to the extruder body using 4 x 10mm M3 screws. Start with the motor almost all the way toward the pressure plate. You will have to back and forth the next few steps until you get the position right as when assembled the idler gear obstructs the left two screws. | |||
 | Step 8: Insert the hobbed bolt with idler gear. | |||
 | Step 9: Add the (small) drive gear and tighten the grub screw. | |||
 | Step 10: Wriggle the PTFE tube of the hot end into the extruder body. Use a small self tapping screw to fix the hot end to the body. | |||
