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Partial Answer Click / Pop on Z axis (R1)

Discussion in 'Troubleshooting' started by PropLord, Jul 21, 2017.

  1. PropLord

    PropLord Member

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    That's what it looks like, but the belt can't get tighter. One detail I forgot to mention was my glass bed broke a few months ago and I replaced it with a 1/4" aluminum plate. I don't think it weighs any more than the glass. And I had been getting perfect prints up until I started this thread.

    I tried it again, upping only the Y to 700, same exact problems. X Z and E seem absolutely fine where they are. No over heating, no slipping or under extrusion.

    Could the motor itself be bad? Oh, and I can't seem to order a new belt from Robo3d's shop. They're not even listed.

    And thanks for the assistance :)
     
  2. PropLord

    PropLord Member

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    Upped it to 725, it gets pretty warm, it printed a bit better, but it's still slipping a good deal. Definitely a tooth slip. I think it is the belt at this point.

    I removed the metal plate, told Y to move a bit, then pushed and pulled the frame manually by hand. I saw the belt give a little and bounce. Not sure how since it is crazy tight when it isn't moving.

    I guess I could get another belt from Amazon? If I can, do you know what belt size I need?
     
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    GT2 belts.
    You may need to slow the bed travel down, just a thought.
     
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  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Make sure the drive cog for that belt is FIRMLY attached to the stepper motor shaft and not slipping.
     
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  5. PropLord

    PropLord Member

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    Thanks!

    I tried slowing it down already. I used to be able to do 1.25-1.5 reasonably ok until this major issue popped up. It didn't even print correctly at 0.80.

    I'll make sure that the cog is on correctly.
     
  6. PropLord

    PropLord Member

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    I replaced the belt, tightened it up a lot, and did another print. Y shifted a couple times, but far less than before. So, I tightened it even further. It only shifted once that time. I went to tighten it once more, but I just don't know if it's even good to have it this tight. The further I pull the bed forward, the it gets harder it becomes pull. Pushing it backward seems to release the tension (wherever it is?) and it becomes easy to push. Up until the Y homing button is just about to get touched, the pressure increases again, though only slightly.

    Can you have the belt TOO tight? Are the wheels next to the motor too tight? Any idea?
     
  7. Geof

    Geof Volunteer Moderator
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    Is the belt riding up and down the bearings (the wheels) ? I'd bet so. I'd the belt is new and tight you can loosen up the bolts on the bearings(wheels) and it may help
     
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  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    @Geof probably nailed it.
    Lift the bed and watch the belt on the center pinions while you slide the rails back and forth.
    This happened on my beta unit too. The sprocket on the motor shaft has to be positioned just right (vertically) or the belt will see-saw on the pinions and bind towards the edges. Very sneaky problem...
     
  9. PropLord

    PropLord Member

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    I loosened the bearing/wheel on the side that was binding. It doesn't stick now. However, I checked to see if the belt moves up/down any while pushing / pulling and it does move, but seemingly only by 1 mm~. Is that normal? If not, how do I fix it?

    Also, when I lift up on the bed on either side it seems like it rocks. I'll record a video in a bit so you know exactly what I'm talking about in case I'm not describing it well enough.
     
  10. Geof

    Geof Volunteer Moderator
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    run some prints and see if the shifting is gone. a little up and down and you may be ok. The bed rocking sounds like you have some linear bearings that are bad. (possibly shafts too) but I'd fire up some prints before I got to worried about it.
     
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    It should not move up/down, but as long is it is not causing binding (rubbing up against the wall of the capstan / belt race) it would still work.

    The way to fix this is to raise or lower the belt cog on the shaft of the motor until it is level with the belt race on the capstan. You can see this visually... The belt should level across from the center capstans to the drive cog on the motor.
     
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  12. Geof

    Geof Volunteer Moderator
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    random thought occurs - you may want to check the belt tensioners that screw through the bed "frame" and make sure they arnt cracked. it could be causing you some "variance" as well
     
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  13. smith59

    smith59 New Member

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    i agree with mark, theyre so cheap it isnt worth the time nor headache.
     
  14. Doug Meek

    Doug Meek Member

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    Make sure nothing is wrapped around the drive cog on the motor. I had a piece of aluminum tape get wrapped around mine, could barely see it looking at the gear teeth, causing it to skip during prints. It also made the tension vary as I moved the bed front to back like you described. The aluminum tape piece came from the heater tape getting ripped up on the rollers, and drive cog in my case..

    You could also have an intermittent connection on the Y stepper cable assembly?
     
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