Anycubic i3 Mega S X-Belt Tensioner MK.III

Anycubic i3 Mega S X-Belt Tensioner

UPDATE:

This MK.III design has been revised to be more robust and more streamlined. I currently use this on my own printer.

Failing to find any good stream-lined design out there, I went ahead and designed my own X-belt tensioner. You can really torque this down to the appropriate tension without anything coming loose.

DESIGN SPECIFICATIONS:

Streamlined design with zero interference.
Print without supports.
Ease of installation with the use of existing holes without the need for drilling into the machine or modifying anything else.

HARDWARE NEEDED:

4 x M3 screws of the appropriate length to secure Part A to Part B of the belt clamp

4 x Longer M4 screws to extend the current screws where the current linear rod bearings mount to (to affix your Belt Tensioner Main Body).

4 x M4 nuts

4 x M2.5 heat inserts

Misc. washers to distribute load on the head of the screw if you wish.

INSTALLATION:

1. It is pretty straightforward. Clamp belts with Part A and Part B affixed together. Use M3 screws here. The hole is undersized so you will thread into the plastic.
   NOTE: The original Anycubic i3 Mega S belt is slightly thinner than a Gates belt, if so, you will have to fold the belt on itself (with teeth facing outward so it will mesh into the clamp). When you fold it on itself, make sure that a little loop of the belt sticks out the front, insert a short wire into this loop to prevent the belt from slipping loose when you torque it down.

2. Heat-set 4 x M2.5 inserts into the Main Body.

3. Install Main Body between the two linear rod bushings by using longer M4 screws coming through the front side. Make sure to press the Main Body toward the linear rod bushing housing as you thread the M4 screws from the front. Optionally, secure with M4 heat insert (as a nut will not fit due to clearances).

4. Tension the belt by screwing both left and right side of the Belt Clamps into the Main Body.

NOTE:

The design is dimensionally accurate. If you are not getting accurate parts, then your printer needs to be tuned and calibrated to print accurate parts. The design has been printed and checked for dimensional accuracy.

As mentioned above, you need to have a calibrated printer that prints accurate parts. All of the dimensions have a tolerance of 0.05mm.

Print with PLA if you don't expose your printer environment to higher than 50ºC. Otherwise, use PETG or even better use ABS/ASA. The parts are small enough that you can probably get away with printing ABS without an enclosure. Use a brim or a raft to assist with bed-adhesion and avoid warping.

Print with 100% infill.