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Solved Y-Axis Issues

Discussion in 'Troubleshooting' started by WindDrake, Dec 25, 2016.

  1. WindDrake

    WindDrake New Member

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    Had something strange happen today when printing a large object on my R1+. It is running a Smart LCD Controller, as well as Marlin RC8

    Mattercontrol, by default, thinks that the bed is 228x254x200.

    Using that setting, I attempted a print and ended up with a squished back-end.

    Checked the Y-Axis mechanical parts first, found that the pulley on the stepper was down too far, and the belt would walk up the pulley, causing the whole system to bind (but not fail). Found that the double-setscrew gear's hole was undersize to the 5mm stepper shaft, and that they had pressed the damn thing on. Had to use a gear puller to remove it, then bore the hole to proper 5mm and reinstall at the proper height.

    Still didn't fix it.

    Manually commanded the tray around and found that it stopped at 236mm.. Far short of the advertised 10" Y-Axis.

    Decided to check Marlin's configuration.h, and sure enough, the firmware is set to 220x236x230! While I'm not going to complain too much about 8mm on the X-Axis, 18mm on the Y-Axis definitely screws things up.

    Setting the firmware temporarily to 254 on the Y, I checked the actual mechanical limit and found it to be 249mm (or 250, seemed like 249 began to bind). I then set the firmware to 245mm, and all is running nicely now.

    245mm/9.64" I suppose isn't the end of the world, it is just not quite as advertised. However, the extra 30mm Z-height was nice!

    I suppose this isn't so much a troubleshooting post as it is a post for posterity's sake. Hopefully this helps someone else in the future. For me, it cost 30 hours of printing time and about 80% of a pound of PLA. :(

    Also, Robo3D, you guys might want to look at those pulleys. A double grubbed screw doesn't need a friggin' interference fit when the load is all radial. A fork-style height gauge between the stepper body and bottom of the gear would easily set the proper standoff height at manufacturing time, and not require it to be eyeballed by an operator on an arbor press.
     
    mark tomlinson likes this.
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Sadly Robo3D themselves do not often read the forums.

    Inhad that same issue on the Y axis pulley with my original beta. Good job catching it since finding my post from back then would be hard. ;)

    Sent from my SAMSUNG-SM-G930A using Tapatalk
     
  3. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    @WindDrake If you are using my modified version of RC8 then the firmware limits X, Y and Z to 220, 236, 230 because when I tested my stock Robo R1 with the original firmware set at 240, 254, 240 if you actually tried to move to those limits it would bang into the end of the movements and grind. I have no idea where Robo got those numbers other than maybe on paper. The printer could not physically move there. That doesn't mean that my numbers are accurate either, just that they shouldn't bang into the mechanical end of the axis. Your particular printer might be a mm or two different, but likely not more than that. So all the mods I have done use 220, 236, 230 as the maximum bed dimensions.
     
    Geof and mark tomlinson like this.
  4. WindDrake

    WindDrake New Member

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    @WheresWaldo - No worries. I've dialed my firmware in for the mechanics of my specific printer now. I should have known better than to trust the assumptions of any software, so I half blame myself. :)
     

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