Problems Removing HotEnd Heatsink from X-Carriage

Discussion in 'Calibration, Help, and Troubleshooting' started by Old_Tafr, Apr 13, 2016.

  1. Old_Tafr

    Old_Tafr Well-Known Member

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    I have removed both fans and IR sensor for access, I have removed the temp sensor and heater and unscrewed the heatbreak from the heat sink so only the heat sink remains.

    I have also removed completely the two grub screws that hold the heat sink in position i.e. the one from the front (easy access) and the one from the rear (mirror on a stick very handy here) the heat sink moves down ok until the lower of the two bosses (the smaller section than the fins) is visible and I can see 2 to 3mm the smaller diameter section between the two bosses, but at this point the heat sink will not extract any further.

    Pushing the heat sink up, and then pulling down with a little force, it feels like the heat sink hits something solid.

    The only thing I can imagine this is, is one/both of the square nuts that the grub screws screw into. As I didn't have a problem inserting the heat sink I cannot immediately see why the nuts could get in the way, but short of applying quite a lot of force I can't see how the heat sink could come out.

    I had tried removing the heat sink before fully removing the grub screws so I can't see that removing these completely allowed the nuts to come loose and obstruct the heat sink.

    As it is can clean the nozzle etc. without removing the heatsink and the path through the heatsink to the hobbed filament drive is clear too so I can just reassemble without removing the heat sink but it's just puzzling as to why it won't come out.
     
  2. Miasmictruth

    Miasmictruth Well-Known Member

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    I have had the PTFE tube get stuck before holding the whole heatsink up, I usually gently pry with a screw driver to pop it free. I put the shaft of the screwdriver on the lower ring and try to hold the heatsink straight.

    I am not sure I recommend it as your taking a risk but just as a thought..
     
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  3. Pierce

    Pierce Well-Known Member

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    The grub screws go into bolts, those bolts slot in from inside the hole, so taking out grub screws the bolts could have slipped into the heat sink almost locking it in place, put the grub screws back in and try again, I also use the level it out with a screw driver method :)
     
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  4. Old_Tafr

    Old_Tafr Well-Known Member

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    Thank you kindly both of you ! I did this... put the grub screw back in the front... no difference, maybe worse. Looked at the other with a mirror on a stick before trying the screw. The nut was not aligned i.e. it had slipped into the bore the heat sink fits in, so it slipped into the gap in between the two bosses, so not possible to get the screw back in, but.... a small and worn at the end screwdriver (used for aligning things like these nuts) brought the nut back into line and some slight force with a screwdriver pulled the heat sink free.

    I had not cleaned out the holes for these nuts, just inserted as was, so this may well be a problem for anyone trying to remove the heatsink when the nuts come loose. Probably best to not quite remove the grub screws, but it is impossible to tell if they are engaged or not.
     
    #4 Old_Tafr, Apr 13, 2016
    Last edited: Apr 13, 2016
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