A new guided wizard has been added to the Prusa CORE One L to help users properly tension the X/Y belts. The printer uses controlled belt excitation combined with stroboscopic feedback to visualize belt resonance, making the tuning process more intuitive and reliable.
The wizard, accessible via Settings → Manual Belt Tuning, begins by prompting the user to check that the gantry is properly aligned, as misalignment can affect measurement accuracy. A quick manual alignment can be done by loosening both tensioner bolts, gently straightening the gantry by hand, and re-tightening the bolts evenly while keeping the gantry square. More information about gantry alignment can be found in this article.
The wizard then measures the vibration frequency of both belts and recommends whether to tighten or loosen them. The target frequencies are 96 Hz for the upper belt and 92 Hz for the lower belt. Important: Always tighten both tensioner bolts evenly and alternately. This ensures that the gantry stays square during adjustment.
 |  |  |
NOTE: A difference of up to 8 Hz between the belts is acceptable, as long as both values remain within the 90-98 Hz range. If values cannot be reached, the wizard will suggest manual squaring before continuing.
If your gantry is out of alignment, you may not be able to reach these exact values. In some cases, the lower belt can even show a slightly higher frequency than the upper belt.