Anet A8 PLUS X-Axis Tensioner

thingiverse

This design is crafted in millimeters. If your slicer expects inches when you import this, it will be extremely tiny and you'll have to scale it by a whopping 25.4 (2540%). I probably tried every X axis belt tensioner for the Anet A8 on Thingiverse. While some are very good designs, nothing was really exactly what I wanted. All of them snapped after extended use. So this is my solution. There are several benefits to this design. It doesn't require a fixture on the end of the axis that presses on the guide rods. While those tensioners can work well, if you like to run your belts extremely tight, the pressure on the guide rods can cause them to deflect and affect print quality. The "anchor" point for the tensioning screw in my design is a bolt instead of a printed feature that's prone to breaking over time. Blind screws are threaded and epoxied into the "teardrops" for additional strength. Finally, the bolts that pass through the slider allow it to positively lock the adjustment in place. This should be the last tensioner your A8 ever needs. This should work on the original A8 as well, as long as you have the plastic bearing blocks and not the big aluminum ones. I haven't tried it on my original A8, so print it at your own risk. Please let me know if it works. There are a few things you'll need to do to make this work: 1) You'll need to reverse the X Axis motor. This is very simple; I reversed the pins at the motor connector. 2) You'll need to source an M4 eye bolt. I used the one from the stock Y axis tensioner that came with my A8 Plus. If you upgrade to my Y Axis tensioner (https://www.thingiverse.com/thing:4007384), you can repurpose the eye bolt here. 3) You may need to sand the two halves where the guide rail fits together. This needs to be a nice slip fit. To adjust tension, simply crack the 3 bolts in the slider loose and adjust tension with the M4 nut, then tighten the bolts back down. BOM: (1) M4 eye bolt (repurposed from stock y-axis tensioner) (1) M4 nut (2) M3 x 10mm socket head screws (6) M3 x 20mm socket head screws (3) M3 Washers (1) M4 Washer (1) Epoxy - for gluing the M3 x 10mm into the teardrops