1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Upgrading the Robo C2 with cantilevered stability - Instructions

Discussion in 'Mods and Upgrades' started by OutsourcedGuru, Oct 10, 2017.

  1. OutsourcedGuru

    OutsourcedGuru Active Member

    Joined:
    Jun 3, 2017
    Messages:
    752
    Likes Received:
    137
    I've created a repository with step-by-step instructions for adding Y-axis stability to the cantilevered print bed. This should add firmness in this dimension, in theory, and lower the amount of ringing seen in tall parts especially near the front.

    The existing design is a bit of a diving board and too prone to vibrations. This is an attempt to fix that.

    CantileverStabilityPlate.png
     
  2. OutsourcedGuru

    OutsourcedGuru Active Member

    Joined:
    Jun 3, 2017
    Messages:
    752
    Likes Received:
    137
    Hair dryer, for the win! Note that this slicing doesn't include a raft, skirt or brim and the edges are about 1mm thick.

    A few moments ago, I walked into here to check on this print job and it's maybe an hour into it and only perhaps a millimeter's been laid down (relatively big part)... to find that the front two corners were badly curling by this point. Rather than aborting the job, I brought the hair dryer and began heating those two corners while edging it back into place with the back of the tweezers. Success!

    I then carefully applied gentle pressure along the front edge as well, "gluing" it back to the print bed. As the extruder returned, I followed along behind the path with the tweezers to coax it back down. I expect to have to do this for a couple more layers but I just saved this part.
     
  3. OutsourcedGuru

    OutsourcedGuru Active Member

    Joined:
    Jun 3, 2017
    Messages:
    752
    Likes Received:
    137
    Installed it and it's working great. It's dampening that diving board effect, as expected.

    Notes:

    * Couldn't find any hex cap aluminum bolts as small as M3 at Ace Hardware so I ended up with some little capped version of these in some other material. They worked out fine at 12mm in length but I think I'd recommend more like 10mm since the remainder is superfluous.
    * Start a bolt in all holes first to make things easier. Install them from back to front since it's a little difficult to find the tiny holes.
    * Lock washers appear to be unnecessary.
     

    Attached Files:

  4. Frank van Gilluwe

    Joined:
    Sep 27, 2017
    Messages:
    47
    Likes Received:
    21
    Interesting project. Did you actually see the vibration in the bed? I haven't noticed any (visually) on my jobs. I've looked a bit too intensely on some jobs watching the bed rise and fall as it auto-compensates for a non-level bed when moving the extruder around. I guess the real key is in the results - does it help align the layers a bit better?
     
  5. OutsourcedGuru

    OutsourcedGuru Active Member

    Joined:
    Jun 3, 2017
    Messages:
    752
    Likes Received:
    137
    Boing, boing, boing... (yes). It was annoying to watch the front-side of the bed bouncing like that and knowing that this was likely translating into ringing in the z layers. It's now much more solid, trust me. This has to be the easiest/cheapest/best upgrade I've done for this printer. I really have no idea why they'd include all those cutouts in the bed platform itself; this just leads to the loose nature of the print bed assembly.

    Read the notes about curling above. You'll want to babysit this one for a portion of the print.

    The bolts I used were M3-0.50x12 but I would guess that 10mm long would be perfect. Ace Hardware's part number is 43829D for these. I used a black version but they look like this.
     
  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    21,138
    Likes Received:
    6,997
    I'll give it a try as soon as the printers are back in action.
     
  7. OutsourcedGuru

    OutsourcedGuru Active Member

    Joined:
    Jun 3, 2017
    Messages:
    752
    Likes Received:
    137
    Oh... I didn't see this part earlier. We had a talk about this subject and some like and some don't like the G29 auto-level routine (preferring to manually level theirs). For a bit, I toggled off auto-leveling completely and focused on leveling the bed manually. You can see my shims here in this picture: DSC_0094_4.jpg. Honestly, there are eight slices of paper on that back/left corner and there are none on the front/right; that's ridiculous.

    If you're seeing z-adjustments mid-layer then it's just wasting time. I think I'd suggest that you make an attempt at leveling it as I did, re-adjust your z-offset as necessary and see if it gets more solid first... and then do the mentioned upgrade here for cantilever.
     
    mark tomlinson likes this.
  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    21,138
    Likes Received:
    6,997
    Manual leveling FTW with the C2.
    I'd even be tempted with the R2, but would probably go with mesh there.
     

Share This Page