Anet A6 X-axis belt tensioner

There is some effort to make this upgrade, but it's the most elegant solution I've seen so far, it doesn't require to reprint many parts and integrates seamlessly.

For this upgrade you need to make a minuscule modification of the acrylic box for x-axis where the idle bearings are. The belt tensioning bracket uses the hole for the plastic cover of one of the steel rods, so you need to drill one 3 mm hole in the acrylic near the right edge of the box for the cap. I used a slightly smaller drill bit and made a thread with the screw directly in the acrylic, so I won't be needing to use a nut on the other side. If you choose to do the same, have in mind that the acrylic is very brittle and you may need to tap the thread before screwing the screw.

You can cut the bracket from 1.5-2 mm sheet of aluminium. More is too thick and will mess up with the dimensions, less is too weak and will bend under the tension. The bracket is designed to accommodate a G2 idler pulley with 16 teeth, which is larger than the original F623ZZ bearings. Critical dimensions are the height of the hole for the tensioning screw from the bottom leg of the bracket (should be 13.5 mm) and the holes for the pulley - they need to be at least 7 mm away from the back of the bracket after bending to provide enough space for the pulley. If you make yourself a 3d-printed pulley, they are even bigger and the holes must be at a distance of at least 8 mm. The height of the holes from the bottom of the bracket must be 23 mm, so the pulley sits at the same height as with the original mount.

The original bracket was made from two pieces connected with a rivet. I preferred to cut mine from a single piece of Al sheet, this way the pulley does not have a chance to rotate axially.

Make sure there is no drag from the pulley screw on the 8 mm steel rod. The outer pulley hole may need chamfering and the screw may need to be with a cone head to stick less. If there is a drag, you need to trim the screw head to be flush with the bracket surface. On the other side I am not sure there is a place for two nuts, so either use single one (you can use locknut) and cut the screw or use two half nuts so they stick less.

The knurled knob needs a a standard M3 nut to fit inside. It's recommended to use a soldering iron to push it, so it stays firmly. You don't have to push it beyond the surface, cause the tension can pull it out. It needs to be flush on the surface of the knob and to touch the acrylic box of the printer.

Print Settings

Rafts:

No

Supports: 

No

Resolution:

0.2 mm

Infill: 

30%

Filament: PLA 
 

Notes:

Nozzle diameter: 0.4 mm

Category: 3D Printer Parts

The original upgrade was very poorly explained and documented and contained unnecessary cuts and mounts.