Sock-sag

Discussion in 'Calibration, Help, and Troubleshooting' started by Spoon Unit, Dec 30, 2016.

  1. Spoon Unit

    Spoon Unit Well-Known Member

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    I do like the new socks for the hot end. Certainly it keeps everything looking a lot cleaner and permits more aggressive part cooling. One thing I do notice is that, over time, the sock begins to sag, no longer effectively gripping the top of the hot end. I wonder if anyone else has noticed and/or come up with a solution. At the price they are, I can happily just re-order more. Is sag just an indication that it's time to change, or a design flaw to induce repeat-purchase? Is there an actual degradation in the sock that means I really should change it. Has anyone created some sort of item to help apply pressure to keep the top of the socks over the top of the hot end. Could it just be that the hot end is dirty from previous-non-sock use and that small amount of crap is enough to cause sock droop?
     
  2. Kanedias

    Kanedias Well-Known Member

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    I never thought I'd be talking about droopy socks but yes I've noticed it too. Built in obsolescence? Shocking. :D

    I thought about using a loom band to hold it on but I haven't tried yet
     
  3. Ephemeris

    Ephemeris Well-Known Member

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    I thought about making some clips out of spring steel enclosed in a length of teflon heat-shrink tubing to avoid shorting the heater accidentally, but I haven't tried it yet
     
    #3 Ephemeris, Dec 30, 2016
    Last edited: Dec 30, 2016
  4. Kanedias

    Kanedias Well-Known Member

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    Heat shrink!
     
  5. mike01hu

    mike01hu Well-Known Member

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    I found that there is a gradual build-up of filament under the nozzle due to capillary(?) action that eventually pushes the sock down such that the sock touches the printed surface and drags slightly causing further movement of the sock; I clean under the sock regularly.
     
  6. Jasons_BigBox

    Jasons_BigBox Well-Known Member

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  7. Spoon Unit

    Spoon Unit Well-Known Member

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    Will have to remove and de-fluff !
     
  8. Spoon Unit

    Spoon Unit Well-Known Member

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    Wow. I wonder what those things are made of ... I guess it must be ABS-based or there's no way that would have stayed. I like this idea though. I had tried bending a paper clip around the sock and just couldn't get it to settle.
     
  9. Spoon Unit

    Spoon Unit Well-Known Member

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    Is all heat-shrink made from Teflon then?
     
  10. Ephemeris

    Ephemeris Well-Known Member

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    No. Most are much lower temperature plastics. Also teflon tubing can't shrink as much other types. My usual go to is polyolefin but teflon is your best bet at high temperatures. Any higher and you go to fiberglass sleeving or some other non metallic non polymer.

    If you're curious go here

    https://www.mcmaster.com/#heat-shrink-tubing/=15p70cn

    You'll find
    a very helpful table if you click on

    About Wire and Cable Protection
     
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  11. Spoon Unit

    Spoon Unit Well-Known Member

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    OK. So I just pulled the saggy sock off. Here it is, as it came off, side by side with a brand new one.

    ApplicationFrameHost_2016-12-31_00-15-05.jpg

    As you can see, I don't seem to get a lot of build up on the bottom of the sock. Any kind of print fail inevitable leads to friction against the sock and, as you can see here, the hole has enlarged itself. I think sagging could also lead to this hole enlargement and that could well add to a build of material inside the sock. However ...

    ApplicationFrameHost_2016-12-31_00-15-29.jpg

    As you can see here, I have virtually zero content inside the nozzle. There is some sticky stuff in there though, so perhaps that's what Mike's talking about. It's also discolored slightly vs a brand new one.

    A closer inspection inside ...

    ApplicationFrameHost_2016-12-31_00-15-45.png
    ApplicationFrameHost_2016-12-31_00-15-56.png
     
  12. elmoret

    elmoret Administrator

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    It isn't an intentional design flaw to induce repeat-purchase, it is a limitation of the material. Silicone will deform at these temperatures over an extended duration. It doesn't make sense to use a more exotic material as that would increase prices of the socks which are meant to be disposable.

    Further compounding the issue is that the "fingers" of the sock can't really lock around the top of the block, since they have to have cutouts to allow the sock to be changed without removing the heater/thermistor cartridge.

    Some folks have used a thin wire wrapped around the sock near the top of the block to hold it on.

    Zip-ties are normally nylon btw, not ABS. ABS doesn't have enough impact resistance/flexibility.
     
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  13. Spoon Unit

    Spoon Unit Well-Known Member

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    Glad you cleared that up. I was kidding :)

    Just feels like a touch extra on the finger tips would have helped.

    My cable tie was too short, so my paper clip has just done exactly this. Knowing my luck I'll have a disaster print that tears the sock to pieces sometime soon.

    Now you mention that, I should have guessed.

    Well, I'll be ordering some more socks anyway. They're too useful not to have, and that was my last one I just fitted. Hopefully the wire will keep it from sagging though during it's intended life span.
     
  14. Spoon Unit

    Spoon Unit Well-Known Member

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    So here's how this ended up with the paper clip in place:

    ApplicationFrameHost_2016-12-31_14-25-09.png ApplicationFrameHost_2016-12-31_14-25-27.png
     

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