Tevo Tarantula Single Motor Dual Z Axis

thingiverse

These modifications are designed to convert the Tevo Tarantula Dual Z axis from a single motor setup. Complicated trade-offs are omitted here. No more motor couplers will be needed, simplifying things significantly. This setup is slightly trickier than dual motors but requires no additional electronics. The brackets used have been remixed from excellent designs by thingirob and completely reworked to look distinct. Note that tolerances were added where the original parts lacked them; these should print fine without scaling adjustments. You will need two Z Nut holders, which are included in the name as a reminder. A photo showing version 1 is provided, but note that it has been updated since then with improvements based on my experiences. Additional Hardware Required To assemble this setup, you will need several parts, many of which were spare screws or leftover from previous modifications to the printer. These include: A 900mm closed-loop GT2 belt, which I found at a very low cost on AliExpress. The link may disappear if the seller stops offering it. Four 608 bearings Two 400mm lead screws with matching threads and standard brass nuts Two 8mm bore 20-tooth pulleys, available from the same seller I used One 5mm bore 20-tooth pulley for the motor, also purchased from the same seller Two Smooth Idler Pulleys with a 16mm diameter, which are commonly found and used on other axes of the Tarantula printer Two 25mm M5 screws, possibly longer if desired Nylon spacers or nuts (two of them) M5 washers to properly space idlers (four were used in my setup) Two M5 nuts, ideally nylock nuts for added security A Nema 17 motor from the original Z axis Four M3 screws to mount the motor (these should already be included with the original brackets) Eight M3 screws and nuts to secure brass nuts M4 T-nuts or other suitable fasteners for belt tensioning Firmware Changes Required Inversion of the Z motor direction is necessary in the firmware for this setup to function correctly. If thread pitch has been altered, further adjustments may be required. Important Notes and Considerations It has been pointed out that unless alignment is perfect, supporting screws on both ends can lead to binding issues. However, I do not have a problem with this myself; if you do encounter an issue, simply removing the bottom bearings should resolve it. As with any modification to a printer, thoroughly test the Z axis through its full range of motion to ensure smooth movement and prevent potential binding issues. You may need to increase the current to the Z motor slightly as it works harder than before. Additionally, you might require a longer motor wire due to the moved position of the Z axis; this will depend on your electronics mounting setup. Feedback and Improvements I appreciate any feedback or assistance in addressing problems. Improvements made from version 1 include: Removing material to improve strength Adding ribs to upper brackets for added strength Fixing an alignment issue with some holes Adjusting hole spacing under bearing blocks to ensure all previous holes remain accessible Increasing the motor travel to allow for more belt tension if needed