Keep books tight, upright, and near the front, minimize the gap above by lowering shelves, keep cases away from drafts, and do quick weekly dusting.
Clean closed books with a soft dry cloth from spine to edge, use a barely damp wipe only on glossy and dry it right away, keep uncoated paper dry, use a tiny bit of pH neutral on leather, and avoid alcohol or ammonia.
Quick note — Glad that worked for you, but just a small caveat: adding tape or a wedge can increase drag and might stress the motor or affect any warranty. Before modding, try emptying and washing the hopper to remove oily crumbs that cause bridging, dry it thoroughly, and keep the unit perfectly level with some headspace instead of filling to the brim. For me, slightly larger but fewer portions cleared the chute more reliably than many tiny drops.
