Styx i3 Machined Extruder Bolt

thingiverse

I'm going to share with you how I machined the extruder bolt for the Itty Bitty Belted Extruder http://www.thingiverse.com/thing:389105. I figured some people might be curious about it, even if they don't have all the necessary equipment. This extruder bolt is designed for 1.75mm filament. Here's what I did on my lathe: centre drill a M8 bolt first. Then, using a milling machine, mount that bolt in a dividing head with the steady. Next, centre a 4mm slot drill along the axis of the bolt and position the tool to match. Touch the slot drill to the top of the bolt, zero out the Z-axis, pull back, then drop it down by 1.5mm. Start making cuts, feeding the Y-axis until the tool's centre is 4.4mm away from the bolt's centre. Repeat this 24 times with the quick indexer on the dividing head. That will give you 24 evenly spaced notches in the bolt. I hope that made sense - it's a lot easier for me to make one than to explain how I did it.