Feeding filament from the drawer underneath may cause filament feed issues which could affect print completion and quality. This is a simple alternative filament feed system you can print on almost any 3D printer and is not greatly more than a side mounted spool holder (designed for the recommended 900gm MakerBot PLA spools). The concept is that the lengthy feed path through Teflon tube from the base of the Z18 combined with the 'uphill feed path can cause excessive resistance so not enough filament is always available quick enough on demand from the machine. In addition, the filament on some spools can be slightly stuck to underlying/adjacent filament which means extra tension is required to pull it away. All of these issues could cause under extrusion and this spool holder is aimed at reducing these factors to achieve better print reliability and quality. . There is only one print to make this change. It includes two pieces... a spool holder and a threaded bolt to secure it to the side of your Z18 with the lid removed. Please read the instructions carefully and refer closely to the images to see the correct fitment (... but it's not exactly rocket science) STL Files/Versions: The standard .stl is designed for use with standard MakerBot spools. A 'Wide' and 'X-Wide' version has been added that will take alternative spools up to 60mm and 80mm wide respectively. This is still a screw on fitting (80mm version should accept 1Kg MakerBot spools. Not tested but should be okay). Add-on Accessory: Also added is a 'Filament Guide'. This is useful when running a new very full MakerBot spool as the filament can run over the top and into the inside of the spool holder. When placed along the side of the Z18 in between the spool and filament entry into the cabinet, this little attachment stops the filament from being able to unwind high enough to get over the side of the spool and drop down the side of the spool holder. Very small but useful addition... Print with Raft but no support. Use 4+ shells and at least 30% fill to ensure adequate strength. After printing and removing the raft check the thread on the bolt is clean as possible then it should thread into the threaded part of the spool holder with minimal effort. This will tighten against the inside panel of the Z18. Install mid way across the right side of the Z18 with the lid removed (not required). Disconnect the side feed tube from the Y connector and join with the filament guide tube going to the extruder. They will slide together okay with a small amount of force. Please refer to the images for additional understanding. Hopefully this helps your Z18 feed filament better.