Belted Bowden Extruder with Filament Runout v2

thingiverse

Human Version 3 of my Belted Bowden Extruder with Filament Runout, featuring the following upgrades: 1) High-torque stepper motor 2) Spring-loaded belt idler (Requires two 3mm SHCS/nuts to secure to top frame.) 3) Incorporates additional improvements from v2 Months of assembly under load have demonstrated no signs of frame deformation or deflection. To calibrate E-Steps using the Bowden method, refer to this guide: https://www.matterhackers.com/articles/how-to-calibrate-your-extruder?gclid=CjwKCAiA0uLgBRABEiwAecFnk3e6VjFFCSB7xtvScKdYE5XQoA07qt6EHpYdsgl6DzogomQuEsX0eRoCaWUQAvD_BwE 23apr2019 - Revised middle to rev4 and arm to rev6. Moved the filament path in the middle section downward and rearward to better interface with the MK8 hobbed gear. Lengthened the moment arm from 20mm to 25mm. Increased spring pre-load from 5mm to 7mm, allowing for thicker arm design. Added information block on acceleration and velocity settings for high-speed printers. 15apr2019 - Encountering underextrusion issues when printing at 100mm/s with a 0.3mm layer height. Working on middle and lever modifications to enhance MK8 gear gripping and torsional pressure for the lever bearing. Noted positive results when printing at 0.2mm layers up to 150mm/s speeds. Upgraded large pulley material to PETG, as the original PLA pulley failed. 09apr2019 - Added e-step/step_distance and PLA temperature chart for usability starting points. 07apr2019 - Removed Amazon link to MK8 gears, as they are not hobbed enough for a Bowden extruder. Replaced with Zyltech, providing repeatable results for 1000mm long Bowden tubes. Updated Klipper step_distance for 1000mm Bowden Tube. BOM (may require updates): 4 - M4x25mm screws 4 - M4 nuts 6 - M3 nuts 7 - M3x8 SHCS - 3 for cage and 4 for stepper 1 to 3 - M3 set screw - pulley 4 - M3 washers - (optional) 1 - GT2 Timing Belt - L=158mm W=6mm 79 Teeth in Closed Loop - https://www.amazon.com/gp/product/B014QKEH26 1 - MK8 Drive Gear - http://www.zyltech.com/zyltech-steel-extruder-gear-mk8-or-mk7/ (place notes for MK8 gear when ordering) 4 - 625ZZ Bearings - https://www.amazon.com/gp/product/B07DZYZM86 1 - GT2 Pulley - 16 Tooth - https://www.amazon.com/gp/product/B01IMPM44O 1 - 5mm Dia. x 50mm Long Axle: https://www.amazon.com/gp/product/B01B27MJC6 2 - 7.5mm Dia. x 10mm Long Compression Spring: https://www.amazon.com/gp/product/B01N6RMGD2 2 - PTFE fittings - https://www.amazon.com/Straight-Pneumatic-Fitting-Fittings-Filament/dp/B079SCZZXD 1 - micro switch - https://www.amazon.com/gp/product/B06XFL4MZ2 1 - PTFE Tubing x 30mm long - trimmed in runout sensor box during assembly. 1 - Wire/connectors for integrating switch to controller. 60T Pulley design: https://www.thingiverse.com/thing:16627 Filament Runout Instructions AnetA8/Marlin/Octoprint: https://www.thingiverse.com/thing:3143558 This extruder is being set up on a Piper 2 CoreXY running Klipper firmware. Stepper is driven by a DRV8825 at 1/32 Micro-Stepping. Current Klipper extruder step_distance: 0.000963 with a 1000mm long Bowden tube between Extruder and Hot End. Extruder mounted to Piper 2 frame with: https://www.thingiverse.com/thing:3524983