Neptune 2/2S X-Axis Belt Tensioner

thingiverse

Unfortunately you cannot buy a metal adjustable X-axis for the Neptune 2, and I noticed my previously printed X-axis tensioner I had found on Thingiverse was flexing way too much during prints, so I decided to design my own. This adjustable x-axis belt tensioner reuses all bolts/bearings from the original bracket, and it's footprint is nearly identical. I printed everything with 100% infill for rigidity. Printed in PLA. No supports. Print orientation is as presented. Extra parts needed: 1 - M5x25mm 1 - M5 Washer 1 - M5 Nut 3 - M3 Nut Installation: -Disassemble stock tensioner. Keep all bolts/screws and pulley bearing. -Undo belt from hotend assembly -Place pulley holder in X rail body printed part, M5 threaded hole towards body hole. -Thread M5 bolt with M5 washer through both pulley and body. Washer should squeeze into hole tightly as the bolt is seated. -With some added slack, make a 'U' with the belt and slide it into the body and inside pulley holder. -Slide old pulley bearing into pulley holder in front of belt (spacers are built in, so it's a tight fit) -Thread original M3 pulley bolt through side of body, pulley holder, and pulley bearing. -Install body on rail/bracket using original M3 bolts -Reattach belt to hotend assembly. -"spacerRail" goes on the back side of bracket on the pulley bearing M3 bolt. Add M3 nut after. Leave loose. -Add M5 bolt knob. "spacerHandler" can be added if desired (super glue to bolt knob) -Adjust to desired belt tension using knob. -Tighten M3 pulley bearing bolt/nut to secure position. I hope others are able to find this useful! I wasn't tensioning my belt all that often, but when I would test different tensions, I found it a pain to have to adjust and actually be able to "test". For the Y-axis I did go ahead and buy the metal version meant for Ender 3 Pros (4040 Rail).