Heavy Duty Herringbone Gears for M8 or 9/16 (14mm) Bolts

thingiverse

8/10/17 I ran the 9/16 (14mm) version through netfabb and flipped the gear by 180 degrees. The original printed just fine, unfortunately. 7/9/17 This update is long overdue. I added a gear for those eBay sellers passing off 9/16 bolts as M8s! Additionally, I increased the axle distance to accommodate more custom Wade designs. 9/30/14 I decided to swap my gears, but couldn't find any with a gear ratio other than the stock 47:9. I found thicker gears for Prusas, but since they use different hobbed bolts, they weren't compatible with my extruder, even after experimenting with washers and spacers. So I made my own herringbone gears with a 37:13 gear ratio. These custom gears are direct replacements for stock gears, offering increased durability. They're ideal for those with dual extruder setups. Caution: Although they're direct replacements, you'll still need to modify your firmware! You must change the E steps in your Marlin configuration file to "424". Compile, then upload to TAZ. Don't skip this step! DEFAULT_AXIS_STEPS_PER_UNIT {X,Y,Z,424} If you fail to update your firmware, these gears will not function properly. Please review the instructions before proceeding! Instructions Print settings: * Use PLA only * Layer height: .2 mm * Infill: 50% * Print speed: slow down to 70% I'm a fan of tight herring bone gears, so I've made sure everything is snug! To improve accuracy, please adjust your speed settings accordingly. 0) When slicing, ensure the captured nuts' area faces upwards. You may need to rotate your z axis by 180 degrees to achieve this. If not, you might encounter alignment issues with your hobbed bolt. 1) Drive the hobbed bolt deep into the larger gear to secure its grinding area in alignment with the hole on the extruder. No more than three washers should be needed, depending on your extruder's design. 2) Install the small gear onto the shaft of your stepper motor, but first make sure to drill a small hole in the smaller gear to clear any print imperfections. The smaller gear should rotate very slightly around the stepper motor's shaft. 3) Attach the large gear alongside the smaller gear and secure the hobbed bolt with all bearings and washers. Once the large gear is in place across your extruder, rotate it several times to properly align the small gear. After alignment, tighten the little hex screw on your small gear to secure it tightly. 4) After installing both gears, eliminate any play between them by pushing the stepper motor inward and tightening the three screws found on your motor mount area. Both gears should rotate smoothly, free of wobbles and/or resistance. 5) Open your Marlin configuration file and recompile your program with the updated E parameters for your E variable (change stock 800 to 424).