My latest project is the conversion of the Z-Axis of my TEVO Tarantula prusa i3 to a worm gear based belt drive system.
TEVO Tarantula with worm gear belt drive
The worm gear prevents that the x-axis beam falls on the print (or heatbed) after the motors are switched off or if a power failure occurs.
One of the goals while designing the parts was to ensure that they can be printed without supports and that they can be assembled easily.
The worm gear´s transmission ratio is 1:20 an the pulley has 20 teeth. Therefore the transmission ratio is the same as in the original setup and you do not need to make any changes to the Tarantula´s firmware!
You should be able to use the parts on many printers that are based on 2020 / 2040 aluminum profiles.
Worm gear conversion set
The conversion set can be downloaded from Thingiverse ->
http://www.thingiverse.com/thing:1966483
I will add an assebly guide to this blog in the near future.
Parts list / Bill of materials
 Worm gear mount |
Worm Gear Mount 1 x Printed Worm Gear Mount 1 x Nema 17 e.g. Busheng 17HD40005-22B 4 x M3 Bolt 10mm Buy on Aliexpress 4 x M3 Washer OD 6 or 7mm Buy on Aliexpress 1 x Worm Gear Set Buy on Aliexpress 1 x Timing Belt Pulley w. 20 Teeth Buy on Aliexpress 1 x 5x100mm Steel Shaft Buy on Aliexpress 2x 625 Bearings Buy on Aliexpress 6, 8 or 10 x M4 bolts 10mm (short, mixed or long mount version) 6, 8 or 10 x M4 T-Nuts Buy on Aliexpress Recommended: 6, 8 or 10 x M4 washers (prevent that the printed part breaks while tightening the screws) |
 Return pulley |
Return Pulley 1 x Printed Return Pulley Mount 2 x Printed Belt Guide (Washers) 2x 625 Bearings Buy on Aliexpress 1 x M5 Nut 1 x M5 Bolt 25mm |
 X-Axis connector |
X-Axis Connector 1 x Printed X-Axis connector 4 x M4 10mm Bolts 4 x M4 T-Nuts Buy on AliexpressOther parts 1 x 1m GT2 6mm Timing Belt (with steel core) Buy on Aliexpress |
Hi, why do we need a new motor? The Z-motor of the tarantula isn’t enough?
Hi Leo,
the Tranatula’s motor is perfectly fine.
I have listed the motor just to have a complete bill of materials in case someone wants to use the design on another model.
Why?
Please explain the purpose of this.
Hi John,
some people have problems with their lead screws. In some cases the screws are not straight in other cases the builder is simply not able to mount it correctly 😉
The result can be Z-wobble artefacts. Since the belt does not apply force to the frame the same way a lead screw does it might help to solve such problems.