Linear Module Loose Procedure

Support has a procedure: https://support.snapmaker.com/hc/en-us/articles/1500000110341-What-should-I-do-when-the-slider-of-the-Linear-Module-comes-loose-

I think that it is insufficient and wrote my own. Any reference to Actions is in the procedure on snapmaker support article.

  1. In Actions #1, you might as well take off both ends, there’s no way I found to reassemble without taking both ends off.
  2. Do Actions #2. Eventually, you’ll probably have to take off the other end, too. And make sure that you note which side of the strap is up. You can adjust the bearings without removing the strap, but I wouldn’t recommend it.
  3. My way is to remove the screws from the motor end and carefully move it out to the end of the home switch wire.
  4. Now you will be able to push the slider to the end of the Acme drive screw without messing with the home switch.
  5. Using a thin blade to hold the switch lever out of harm’s way, slide the slider off the guide rails/rods. As in Actions#3, slide the slider out of the Linear Module. Be very careful doing this, the home switch is easily bent.
  6. Carefully wipe the grease off of the slider with a paper towel, otherwise it’ll get all over everything.
  7. Now wipe the grease off (yes, even if you’re wearing gloves) your hands, see, it still gets messy!
  8. A clarification, there are two bearings (of the four) that are adjustable , both on the same side of the slider that has the bright plate under the bearings.
  9. Loosen the bearing screw (3mm) half a turn. This is in Actions #5, note the change in order. This may need to be more if you can’t do step 11 easily. The reason I do this in this order is that with my way you have more control of how much and which way it changes and control is the secret of adjusting anything easy & fast.
  10. Loosen the set screw a full turn. This is in Actions #4. This may need to be more if you can’t do step 11 easily.
  11. Move the cam, two of which can be seen on the long side of the plate, below the bearing. The direction (towards the plastic or away from the plastic) may be different for increase or decrease—it’s a cam , if it’s on one side of a half turn from the other then it’ll be different. Move it using the grooves in the cam with a very small screwdriver, initially, try for about one quarter of the distance between the grooves—if you can’t move it easily, loosen the set screw more. It may also be moved using the bearing screw, just be careful and still use the grooves as a reference. I wish that there was a way to do tis while measuring the setting, but there isn’t, so move the cam a little at a time and do the next step.
  12. Tighten the set screw just lightly snug, you will tighten more later. This will keep the cam from turning as you tighten the bearing screw, keeping the setting from changing.
  13. Tighten the bearing screw, again, just lightly snug, you will tighten more later.
  14. Check for 34.29mm, preferably using a digital caliper, look for the maximum.
  15. If it’s not 34.29mm, redo from step 9.
  16. Tighten the set screw—I can’t tell you how tight, they didn’t give a spec.
  17. Tighten the bearing screw—again, I can’t tell you how tight, they didn’t give a spec.
  18. Actions#8, Assemble the Linear Module, riiight, like it’s soooo easy——NOT!
  19. Unless you have better luck than me inserting the strap into the slider, remove the two black plastic strap guides from the slider, 2.0mm hex.
  20. Clean the strap guides.
  21. Slip the strap into one of the guides, the up side of the strap goes away from the screw, which should still be in the hole—trust me, it’s much easier to have the screw in the hole before the strap in the guide, not to mention putting the whole thing in the slider. The strap touches only the curved parts of the guide. Remember, that the thick end of the guide is the outside and the screw goes in from that end.
  22. Slide the strap and guide into the slider and screw it in.
  23. Slip the other end of the strap into the other guide.
  24. Slide the strap and guide into the slider and screw it in.
  25. Again, using a thin blade, holding the switch lever out of harm’s way and slide the slider back on. Note that:
    a. The plastic on the slider goes in after the metal.
    b. There are two places on the white plastic (as well as the metal) that can damage the switch lever.
  26. Slide the slider to near the Acme screw and set the Acme screw in the slider.
  27. Push the slider and Acme screw together, don’t push too hard or you’ll damage the plastic threads. You’ll have to rotate (clock-wise from the motor end) the Acme screw to start it in the threads of the slider, you’ll know this has started when the slider or the motor move towards each other—rotate the Acme screw a couple more turns.
  28. Now you should be able to push the slider towards the motor, move the slider at least 5cm towards the motor.
  29. Put the bearing cover and the motor back on the extrusion and tighten the screws
  30. Slide the strap to close to either end.
  31. Place a strap anchor on the strap, checking that the small pin on the underside of the anchor goes in the small hole in the strap.
  32. Screw on the strap anchor, but don’t tighten the screws yet.
  33. Do the other end of the strap.
  34. Make sure that the strap is flat to the extrusion—this is why you haven’t tightened the screws yet.
  35. Using the neat little jig that comes with the snapmaker, pull the strap & anchors to one end and tighten the screws there. Make sure that the jig is centered on the strap and not overhanging on to the black end of the module.
  36. Do the same thing with the other end of the strap.
  37. Remember that the home position will probably not be quite the same, but you’re done.

A cautionary note, don’t mess with the screws on the white plastic, one is just a mount, but the other is also for adjusting backlash.

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