It’s highly unusual for a 3D printer belt to be loose enough to cause significant issues. However, print head collisions, though seemingly alarming, can sometimes occur with 3D printers like the A1, often due to factors beyond belt tension.
On simpler 3D printers, a print head crash into the printed object during travel could lead to skipped steps. This results in subsequent movements being misaligned, causing layer shifting and print failures. Fortunately, the A1 Printer is engineered with a smart feature called “Auto-recovery from step loss.” This system is designed to instantly detect even a single missed step and automatically re-home the affected axis before resuming the print.
If your A1 printer continues printing correctly after these collisions, it suggests the auto-recovery feature is partially functional. However, the experience you’re describing – where collisions occur without a graceful correction – indicates the system isn’t working perfectly in your situation. Ideally, the A1 should detect the collision at the moment it happens and smoothly re-home the axis, making the process seamless.
These “crashes” often happen when parts of the 3D print curl upwards. This curling can create an obstacle for the nozzle during its travel movements, especially on subsequent layers. Areas with significant overhangs are particularly susceptible to curling. Furthermore, certain infill patterns, like cubic infill, can exacerbate this issue. The internal structure of cubic infill creates angled walls at 45 degrees, which from the nozzle’s perspective, can act like a “rasp” or “barb,” increasing the likelihood of collision. Therefore, it’s advisable to avoid cubic infill, especially when using filaments prone to curling.
While not directly related to your immediate collision problem, and given your mention of belt tension, it’s crucial to avoid over-tightening your printer’s timing belts. Excessive tension can damage the belts by fracturing their internal fibers as they bend around pulleys. While it’s unlikely you’ve applied such extreme tension, it’s a good practice to be aware of. In printers like the Ender 3, which allow for very tight belt adjustments, users sometimes over-tighten belts, leading to fiber damage and premature stretching, requiring frequent re-tensioning.
