AM8 - 200x300 buildplate - 350mm Z height

thingiverse

As I transformed my A8 into an AM8, I realized that modifying the build plate area should be feasible as well. To accommodate a Y carriage for a 200x300 heated bed without having to cut in the Y carriage or mount the motor on the back of the frame, I designed specific parts. These modifications also allowed me to increase the Z axis to approximately 350mm using standard X axis carriages and 550mm extrusions, which necessitate longer threaded and smooth rods. The challenge of incorporating a larger build plate without cutting into it can be approached in four ways: 1. Raise the Y carriage by placing spacers on bearing blocks, thereby reducing printing height (Z axis). 2. Use spacers on the Y rod holders or design new ones to raise the Y carriage, also reducing Z height. 3. Lower the position of the Y motor, making it slightly more difficult to tension the belt but maintaining a stable structure. 4. Implement a custom-made Y carriage with integral support for the heated bed and a reduced overall height. To address issues related to wobble on my original A8, I designed two new Z rod mounts for the top with 22mm center distance. Each mount will be fitted with a KFL08 bearing and a 20T pulley mounted on the threaded rod. Additionally, a 20T toothed idle pulley and a 20T smooth idle pulley are required for each side, along with a GT2-900mm belt to connect them. The Z top mounts will be installed by first inserting an M3 nut to allow tightening of the smooth rod, then mounting the bracket on the AM8 frame. Next, the KFL08 bearing and 20T idle pulley are mounted in sequence, followed by adjusting and tightening the X axis height and pulleys as needed. This setup mechanically disconnects the threaded Z rods from the X carriages, eliminating any potential for wobble unless additional modifications or components are added to address this concern. Photos of the completed assembly will be provided later. Updates: - On 2018-04-04, I added STL's for Z motor mounts and Z rod holders with additional material for better strength.