linear rod mod for Anycubic Vyper

You're going to need: 

• 7x M5 screws, 15mm long
• 1x T-slot nut
• 2x 8mm outer diameter (+-.2 tolerance) rods, 380mm long
• 4x lm8uu linear bearings
• approx. 1m of GT2 6mm wide timing belt
• 1 belt idler, slim 6mm.
• 6x small zip-ties

The following components will be reused: 

• 2x M2 screws (end stop mounting)
• 4x M5 nuts used to hold the wheels
• Y stepper motor
• stepper motor mounting screws (4x M3, 3x M5)

The following parts will be printed:

• 1x Part A - front tensioner & rod holder
• 2x Part B - heat bed frame to linear bearings adapter
• 2x Part C - back rod holders

Assembly steps:

1. disconnect the Y stepper motor and end stop cables
2. flip the printer to access the bottom side and unscrew 4x M5 bolts holding the Y axis extrusion to the rest of the frame. 
3. Remove the Y extrusion from the frame. 
4. Unscrew the Y motor mount from the aluminum extrusion. 3x M5 bolts.
5. Unscrew the stock Y belt tensioner apart. Numerous screws and bolts. Discard everything plastic. 
6. Move the bed so it slides off the “rail” and remove & discard the old belt.
7. Thread one end of the new belt through the hole in the Y axis extrusion.
8. Slide 2x Part C onto the extrusion on the back.
9. Transfer the screws from the original Y motor mount to the new printed one, screw it onto the Y axis extrusion.
10. Insert the rods into Part A. May require some hammering. 
11. Put 2 linear bearings onto each rod.
12. Insert the other ends of the rods into Part C you have mounted onto the extrusion. 
13. Use 2x M5 screws to screw Part A into the Y axis extrusion.
14. Insert the belt idler and the axle into the belt idler holder
15. Use a M5 bolt and a T-nut to screw the belt idler holder into Part A. Just barely so it holds at the edge of the thread. 
16. Route the belt you threaded through in step 7 to go around the idlers on both ends.
17. Tension the belt with your hands. Find the points where the distance between loops would be more or less 6cm. See reference picture 1 for what I mean by loops. 
18. Use 3 zip ties per belt end to make the loops tight and hold shape. 
19. Measure again that the distance while tensioned is 6cm. Cut the excess if yes. 
20. Use a wrench and a hex tool to unscrew the rubber (POM) wheels from the bed.
21. Use 15mm long M5 screws and reuse M5 nuts to mount 2x Part B onto the bed frame. Use printed washers included in the 3d file on the right side of the bed frame to compensate for difference in hole size.
22. Mount the Y axis extrusion back onto the frame, see steps 2-3 if you forgot.
23. Remove the belt from the motor axle to give yourself some wiggle room.
24. Attach the belt ends to the bed frame.
25. Snap the bed onto linear bearings. Right side first, left side second. (you can be a little naughty and do it the other way around, I don't mind)
26. Slide the belt back onto the Y motor axle. 
27. Screw the tensioner bolt until you feel that the belt starts to resemble a guitar string in it's tension.
28. Marvel at the heretical piece of engineering you just finished.

Happy hacking!

• Reference picture 1.

• Reference picture 2.
   

• Reference picture 3.
  (Note: Part A in the picture is a prototype)