Build a Delta 3D Printer - Going over the flying extruder
The same way the hotend can make or break a printer an extruder will define what kind of filaments you can print and how reliable your printer is, if an extruder is not set up correctly it will either strip the filament by biting too hard on it, clog the nozzle by pushing too much material or not print at all. Building a right extruder for a delta is as simple as getting the right distance between the extruder motor and the hotend. If too long the filament will bend before reaching the hotend, think of it as pushing through a piece of cardboard with a short metal wire or a long one, the long one will be more prone to bending. On the other hand placing your extruder right next to your hotend might not be the right answer either as it will result in the phenomenon known as heat creep, a process through which the heat of the hotend climbs up through the filament rendering it too soft for the extruder gear to bite. For this printer we’re gonna build a flying extruder, a mod for bowden extruders that let the extruder hang over the hotend throughout the whole printing process. Yes, this will add weight to the carriages but it won’t interfere with printing speed. To build the extruder we’ll need three carriage attachments, the printed flying extruder triangle, the motor holder and the extruder mechanism. We’ll need some elastic fabric, a fast pneumatic fitting, some ptfe lining tube, a hobbed gear, a 607z bearing, some M3 bolts and an M4 bolt with washer and nut and Nema 17 stepper motor. Let’s start by gluing the elastic fabric to the carriage attachments and flying extruder triangle, we’ll make a close loop, overlap it and glue it with super glue. We want to make sure the carriage attachment wing is facing up and not down. Repeat this process for the three sides. Add the hobbed gear to the remaining nema 17 motor, put some superglue on the shaft, slide the hobbed gear in and tighten the grub screw. Now we’ll build the extruder mechanism by sliding the 607z bearing on the side and fastening it with the M4 bolt, washer and nut combination, don’t tighten it too much, it should have some play so as to be able to turn when the filament is being pushed. We’ll add an M3 25mm bolt with nut on the side of the extruder mechanism, this nut will be useful for changing the pressure on the extruder when changing to softer or harder materials. Add the fast pneumatic fitting for the ptfe tube lining by screwing it to the opening on the extruder. Now fix the extruder to the motor using M3 10mm bolts. Cut 20cm of Ptfe lining tube and slide in the pneumatic fitting. Now use the motor holder to fix the extruder nema combination to the flying extruder triangle. Use some M3 20mm bolts to fix the carriage attachments to each carriage, repeat the process three times and the flying extruder should now be hanging in the middle of the build surface. The cable length should match the hotend cable so repeat the process for the bottom frame motors, cutting the provided set of cables by the middle, labeling the colors, adding the missing segments with 0.16 cable and making the necessary soldering and isolating process. We’ll set the cable aside for now.
The same way the hotend can make or break a printer an extruder will define what kind of filaments you can print and how reliable your printer is, if an extruder is not set up correctly it will either strip the filament by biting too hard on it, clog the nozzle by pushing too much material or not print at all. Building a right extruder for a delta is as simple as getting the right distance between the extruder motor and the hotend. If too long the filament will bend before reaching the hotend, think of it as pushing through a piece of cardboard with a short metal wire or a long one, the long one will be more prone to bending. On the other hand placing your extruder right next to your hotend might not be the right answer either as it will result in the phenomenon known as heat creep, a process through which the heat of the hotend climbs up through the filament rendering it too soft for the extruder gear to bite. For this printer we’re gonna build a flying extruder, a mod for bowden extruders that let the extruder hang over the hotend throughout the whole printing process. Yes, this will add weight to the carriages but it won’t interfere with printing speed. To build the extruder we’ll need three carriage attachments, the printed flying extruder triangle, the motor holder and the extruder mechanism. We’ll need some elastic fabric, a fast pneumatic fitting, some ptfe lining tube, a hobbed gear, a 607z bearing, some M3 bolts and an M4 bolt with washer and nut and Nema 17 stepper motor. Let’s start by gluing the elastic fabric to the carriage attachments and flying extruder triangle, we’ll make a close loop, overlap it and glue it with super glue. We want to make sure the carriage attachment wing is facing up and not down. Repeat this process for the three sides. Add the hobbed gear to the remaining nema 17 motor, put some superglue on the shaft, slide the hobbed gear in and tighten the grub screw. Now we’ll build the extruder mechanism by sliding the 607z bearing on the side and fastening it with the M4 bolt, washer and nut combination, don’t tighten it too much, it should have some play so as to be able to turn when the filament is being pushed. We’ll add an M3 25mm bolt with nut on the side of the extruder mechanism, this nut will be useful for changing the pressure on the extruder when changing to softer or harder materials. Add the fast pneumatic fitting for the ptfe tube lining by screwing it to the opening on the extruder. Now fix the extruder to the motor using M3 10mm bolts. Cut 20cm of Ptfe lining tube and slide in the pneumatic fitting. Now use the motor holder to fix the extruder nema combination to the flying extruder triangle. Use some M3 20mm bolts to fix the carriage attachments to each carriage, repeat the process three times and the flying extruder should now be hanging in the middle of the build surface. The cable length should match the hotend cable so repeat the process for the bottom frame motors, cutting the provided set of cables by the middle, labeling the colors, adding the missing segments with 0.16 cable and making the necessary soldering and isolating process. We’ll set the cable aside for now.