ACE Pro Filament Clogging Fix – Modified Shift Dial

This shift dial helps correctly position the idler pulley assembly. On some ACE Pro units, a small tolerance issue can cause the idler pulley to sit at a slightly incorrect angle, leading to repeated Error 11518 (filament clogging). A quick way to check for this issue: if you can easily pull the filament backward while the feed indicator light is flashing, the idler pulley isn’t gripping the filament firmly enough. This weak grip can cause feeding failures and trigger clogging errors. This improved dial advances the idler pulley by 5 degrees, moving the idler bearing slightly closer to the extruder drive gear. The result is better filament grip, increased friction, and more reliable feeding—significantly reducing the chance of Error 11518. A no-offset shift dial is included for use as a direct repalcment part.  For the repalacment instructions, please refer to Step 6, item #4 in the ACE Pro Idler Pulley Assembly Replacement Guide on the Anycubic Wiki.  In short: remove the multi-color cover, loosen the shift dial set screw, gently pry out the shift dial with the removal tool, and replace it with the new one. The idler pulley assembly does not need to be removed.