Now that the frame is finished, it’s time to move onto the gantry system.
I am going with a CoreXY based system, but more specifically, the CoreXY system developed by FabTotum for their Totum making machine. Here’s a comparsion of the standard CoreXY system and the FabTotum CoreXY system:
Although they look very similar on paper, there are is one key advantage to the FabTotum system: no belt cross-over. This may seem purely cosmetic, but in fact it makes assembly and operation much easier simply because you are able to avoid any friction from the belts rubbing together at the cross-over.
Here’s my implementation of the Fab system:
I decided to use large 57 tooth, 35mm diameter pulleys to help increase the accuracy of the printer. However, this comes at the cost of reduced torque due to the larger diameter. I hope to mitigate this torque loss by using high torque NEMA 23 motors in the final printer.
Currently I am using printed parts for the x carriage, y carraiges, hotend mount, and idlers. I am designing each printed part so that it can be made out of stock metal parts or machined at a later date.