Pushing The PTFE Into The Hot End

Discussion in 'E3D-v6 and Lite6' started by Thorinair, Aug 9, 2017.

  1. Thorinair

    Thorinair Member

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    Making another thread so I don't spam the previous one I made with unrelated stuff.

    I am assembling the E3D v6 1.75 mm bowden hot end (ordered from the official store), and I can't push the PTFE in for the death of me. I tried to push it in without the heat break screwed in, just to see how deep it can go, and it barely goes in half way. Any suggestions? I thought it should go in a bit easier than that.

    EDIT: Is my PTFE defective or something? I can't even see a way to properly push it into the pushfits.

    EDIT 2: The PTFE's thickness appears to be something like 4.12 mm or so, if that means anything.
     
    #1 Thorinair, Aug 9, 2017
    Last edited: Aug 9, 2017
  2. Old_Tafr

    Old_Tafr Well-Known Member

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    ptfe I have with a Titan, a short length so to go inside the heat sink, is 3.7 mm OD.

    A longer length I have, assumed for a bowden so external to the heat sink i.e. just to fit in the collet, is also 3.7mm OD

    The two lengths of ptfe that arch over the top of my BB taking the 1.75mm filiament from the back of the printer to the the collet at the top of the heat sinks is 4.05 to 4.07mm

    Two short pieces I have left from building my BB, so as a while ago I assume I cut from the long lengths above are 4.05 to 4.17mm OD

    I have tried these pieces in a spare heat sink and they just fit inside the heat sink, inserted from the heat break end, they are a tight fit and one end of one is squashed from cutting and does not fit, it has to be absolutely round to fit.

    (Note that the heat sink dia decreases about halfway down viewed from the heat break end, there should be a drawing in the build instructions possibly, with the size of the holes. Perhaps trying a drill bit down the hole (the shank end and without getting it stuck) would be a way to check the hole size......... another check in a mo when I can find my mm drill bits.

    In the V6 assembly WiKi I think it states what size the ptfe should be........... just searching for this..........

    https://wiki.e3d-online.com/wiki/E3D-v6_Assembly#PTFE_Recommendations

    Interestingly it says..

    Bowden Versions also Include
    800mm of appropriately sized PTFE tubing. :-(


    I could have sworn I saw a ref to some ptfe tubing as 4mm OD , can't remember the ID but I can't see this right now in the above WiKi page

    Perhaps you could post the web page and step you are at (possibly numbered) to understand at which point and where the ptfe don't fit?

    ----------------

    Troubleshooting page

    https://wiki.e3d-online.com/wiki/E3D-v6_Troubleshooting
     
    #2 Old_Tafr, Aug 9, 2017
    Last edited: Aug 9, 2017
  3. Thorinair

    Thorinair Member

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    Thanks for the reply!

    This is the kit I ordered: http://e3d-online.com/E3D-v6/Full-Kit/v6-1.75mm-Universal-Bowden
    Basically, I was assembling the lower part of the hot end and at some point, I had a thought "Hey, I want to see how easily does the PTFE tube insert". So I simply stuck the tube into the heat sink as shown below.

    [​IMG]

    To my dismay, it wasn't going in easily at all. I had to apply considerable pressure to barely get it half way in. The image below shows how deep I managed to get it without much pressure.

    [​IMG]

    In fact, it goes in so difficulty that I almost broke the tube trying to push it in. Then I decided to measure the OD of the tube on both ends. It is 4.12 only if I actually compress it with my calipers, otherwise it is around 4.17, on both ends. Official specs of the bowden tube say 4 mm (http://e3d-online.com/Bowden-Tubing-1.75mm), 0.17 mm deviation is quite major...

    I am honestly not sure what to do. Should I try sanding it down so it is thinner? I did send a support ticket in the mean time, but I would still like to discuss possible solutions.
     
  4. Old_Tafr

    Old_Tafr Well-Known Member

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    It looks to me like your ptfe tube is too big. I have the exact same heat sink as a spare and 4mm OD tubing fits through from the top as per your photo, with little resistance.

    If you have a way to measure the inside diameter of the heat sink, maybe with a drill bit? then this is worth checking, but rather than sanding down the tube you have I would just buy another length from E3D. Support is usually good and I got an immediate (auto-responder with a support ticket number ) reply from the support Email address, and a proper reply within 24 hours.
     
  5. Thorinair

    Thorinair Member

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    Indeed, I will wait until they reply. I somehow doubt that the problem is in the heat sink's ID, because compared to the heat sink, it doesn't want to get in the heat break at all... My printer will sadly be out of action for like a week, considering how long it takes for UK shipments to arrive to Croatia.
     
  6. Antoine

    Antoine Active Member
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    4.17 is far too large for PTFE tubing, this is the most probable reason for it not going inside the heatsink. Bear in mind that as this is an all metal hotend, the PTFE tube does not go through the heatsink into the hot side when a break is inserted, unlike the Lite6, but should be able to go through the heatsink on it's own. Usually, around 32mm of PTFE should be inserted into the top of the heatsink and thus into the top of the heatbreak. Can I just check that you bought this PTFE tube directly from us before I initiate a QC enquiry?
     
  7. Thorinair

    Thorinair Member

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    I definitely did. My order ID is #1082204, it came with the E3D v6 kit.

    I ended up sanding it down a bit, and that worked. I made sure to clean up all debris so that particles don't get into the hot end. I actually ordered a metre more of the tubing today, because I accidentally cut it a bit too short... Oops...

    EDIT: You can also contact Lawson Dallimore, he processed my support ticket so he also has a lot of info on my experience.

    EDIT 2: Maybe it is worth noting that today when I was assembling the setup, I found that the thicker part was only at the ends of the tubes, not along the middle. I found this out when I cut the tube so I can insert it into my extruder.
     
    #7 Thorinair, Aug 11, 2017
    Last edited: Aug 12, 2017 at 12:27 AM
  8. Old_Tafr

    Old_Tafr Well-Known Member

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    It is easy to squash the ptfe tube when you cut it so I think from what you say is maybe what happened. Using side cutters would cause this, sawing isn't an option even with a very fine blade, using a very sharp and strong craft knife and with light strokes is possibly best.

    I have posted previously about the bend in the tube from storage, cutting the ends absolutely straight, countersinking the end receiving the filament etc. all of which if not taken care of can result it the ptfe not fitting, or the filament getting stuck or catching, or being difficult to fit into the heat sink and heat break.
     

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