Anet A8 X Axis Stabilization

thingiverse

The Anet A8 is an enjoyable unit to work with, but it has several issues that require tinkering and improvement. On my model, I discovered that rotating the metal U bracket that holds the extruder to the X axis clockwise and counterclockwise revealed a significant amount of play and wobble. Since I knew that the bearings provided with the A8 are subpar, I first upgraded all three bearings on the X Axis with high-quality German 8 x 15 x 24 linear bearings (Ina Model KH0824PP). I also replaced the 8mm diameter rails with two quality rails from McMaster Carr (400 mm long-McMaster Carr part number 6112K45). The printer became quieter and smoother in operation, but there was still a problem. After researching further, I found that these bearings allow for a degree or less of movement to compensate for alignment issues. To mitigate this issue, I designed an extended pillow block that can stretch out the distance between the upper bearings, creating a larger triangle with less play. Alternatively, using bronze bushings might have been effective as well. Because the blocks are extended and modifying them may require adjusting the X axis offset numbers in software, it's essential to note this consideration. The blocks extend the distance by 2 cm, leaving full axis access to the left side of the printing table and almost to the edge on the right side. They separate the upper bearings by an additional 4cm over the existing spacing. After implementing the mod, I observed a significant improvement in print quality, especially in the X axis direction. The print head exhibited much less play, and a before-and-after comparison reveals the substantial difference. A picture of the Z axis screw clamp was printed before the mod, while the elephant print (for kids) was produced immediately afterward. The results speak for themselves. Due to the new pillow blocks barely touching the X axis limit switch during homing and my preference for wire routing, I also designed a quick mounting bracket for the X axis limit switch. This design utilizes the existing holes on the unit and should be feasible with the original hardware kit. Lastly, belt tensioners are an absolute necessity for the A8, and one of the numerous available designs on Thingiverse can be adapted to your setup. If you attempt this mod, please share your feedback and results as I'm eager to hear about them! Moving on to the Y Axis now.