To fix bed adhesion for 3D models with budget printers, level the build plate, clean the surface with isopropyl alcohol, or use affordable aids like painter’s tape or hairspray.
Leveling ensures even contact (gaps cause lifting), cleaning removes oils/dust that break the bond, and aids add tackiness—ideal for PLA/PETG on cheap printers.
If issues persist, slow the initial layer speed to 20-30mm/s—slower printing lets the first layer bond better, a low-cost fix for most entry-level machines.