Prusa I3 Rework Drop In Replacement/Upgrade Herringbone Gear Set with Solidworks 2014 source

These are drop in replacement Herringbone gears with the same tooth ratio (43:10) as the original spur gear set so you will not need to adjust your e-steps after you swap.
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I never understood why I was seeing herringbone gears that required an entire extruder upgrade to get them to function so I made these.
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After having made this I can tell you there is no way I can feel but the slightest amount of backlash (when I say "slightest" I may actually be over stating it because there is supposed to be some but I can't really feel it) while all spur gears have a lot of backlash that is easily felt.
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Getting these gears to mesh is not the easiest of tasks (nature of the beast) but to make sure they are on right both gear's outer most layer must be flush with each other.
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**01/21/2015 - Added a less material big gear in .stl for those without access to SW2014+ **
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11/06/2014 - I removed the old little gear as I found the hole for the 3mm grub screw was not centered so I fixed that and I made the part a bit beefier where it goes, as well as I enlarged the stepper shaft slightly for an easier fit. Source and the stl have been uploaded