Jamming

Discussion in 'E3D-v6 and Lite6' started by johnrygg, Jun 13, 2014.

  1. Splendid

    Splendid Member

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    Because I use a 100k thermistor :) The original was DOA
     
  2. Mike Kelly

    Mike Kelly Volunteer

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    Unless you modified the heater block to fit a larger thermistor it's probably still a semitec, aka table 5
     
  3. triplanedave

    triplanedave Member

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    So, I’ve been having the same general problems as others with E3D v6.

    Here's what I've noted and tried. There is a small gap created between the heat break and the PTFE tubing. The gap fills with melted PLA/ABS. When retracting, the PLA cools enough to plug up the print head. The plug prevents both forward extrusion and retraction.
    As a solution, I tapered the end of the PTFE tubing before inserting it into the hotend. The heat break accepts the PTFE tubing – but at the bottom of the hole in the heat break where the PTFE tubing is seated, there is a chamfer. The end of your PTFE tubing is usually trimmed with a razor or xacto knife – so the end is flat (squared off). So, I figured that when you seat the squared off PTFE tubing, you create a small gap between the bottom of the PTFE tubing and the chamfered area. Take a look at any plug you’ve removed. Most likely, there is a bulge at the top of the plug. My belief is that bulge was created in this small gap.
    To solve the problem, I simply used some 220 grit sandpaper and tapered the end of my PTFE tubing with approximately a 45 degree taper. By doing so, the PTFE tubing now sits approximately 1.5mm lower in the heat break, and flush with the chamfer.
    I'd been able to run jobs with and without retraction successfully, but alas, a simple print job last night failed to feed properly twice. I'm going to try temp and retraction distance changes to see if I can get better consistency, but as of now, still a problem. Hope this information is helpful - I really want to love using my v6 - but I can't keep failing prints.
     
  4. Inyector

    Inyector Member

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    Good Morning.

    My name is Joseph, I write from Spain. Sorry for my bad English.

    Last weekend, I made my printer with a V6 e3d hotend, 1.75mm. Then I printed the calibration cube, and other parts without problems. But suddenly the impression stuck. I cleaned it with acetone but the problem persists. Prints for a minute, but then it jams. Always this process is repeated.

    I have a nozzle diameter of 0.4. ABS 1.75mm (1.70 measured with calipers), I tested at temperatures from 235 to 270. The same problem occurs.

    I leave you a picture of what I get every time:

    [​IMG]

    I'm thinking of buying it again:

    One nozzle 0.4
    One nozzle 0.6
    1 heat break

    Does this fix it?

    Thanks, greetings.
     
  5. triplanedave

    triplanedave Member

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    Look at the upper end of the bulge. It has an angle to it. Is the end of your PTFE tubing cut at an angle? If so, read my previous post about tapering the PTFE tubing. It may help. However, with as many folks as seem to be having problems with the v6, (including me after having tapered the tubing) my guess is that a new nozzle won't fix anything, and a new heat break might - but it doesn't seem likely that it will fix things. Sadly.
     
  6. triplanedave

    triplanedave Member

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    Update - eating a bit of crow... :) I'm back to having really good prints. Using the tapered PTFE tubing is working. When I was having more troubles, it turned out that my extruder was slipping due to a failure in the idler bearing assembly. I replaced that part, have sufficient pressure on the filament in the extruder, and am getting good prints. Next up - heavy retraction by printing a small chess set. :)
     
  7. ichbinsnur

    ichbinsnur Member

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    Just pay attention To keeping the cooling fan on till the extruder completely cooled down after printing!

    If you don't let the extruder cool down completely before switching off, the Heat rises in the heatbreak and causes the filament
    to melt within the heatbreak, because the cooling fan does not cool the fins anymore.
     
  8. ichbinsnur

    ichbinsnur Member

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    I just checked my temp readings with a thermocoupler on my multimeter ad found the readings
    are way off!

    I get 220°c at the heater block if i set it to 260°c in Repetier.

    Maybe this was the cause for my 0.4 nozzle to jam recently.

    What can i do (Firmware?) to get more correct readings for my extruder temp?
     
  9. elmoret

    elmoret Administrator

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    Try setting the correct thermistor type (5).
     
  10. ichbinsnur

    ichbinsnur Member

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    Thermistor 5 is already set in Firmware.

    I now heated up the extruder and pulled ozt the filament.
    then i stuck the thermocupler of my meter directli into the hotend, right down to the nozze.

    Then i rechecked the temp readings in steps of 10°C

    i found that from about 180°c the readings start do differ in growing span.
    at 200°C in the hotend i get a repetier reading of about 172°C
    at 210°C in the hotend repetier alredy reads 230°C

    I think that may be a cause for the jamming problems many users face (mee too sometimes)

    I 'll try to tweak a thermistor table to get more correct readings, although i don't know if it will
    fit other v6 users as well, might be my thermistor isn't that good ...
     
  11. 3Dmaker4U

    3Dmaker4U Member

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    Hi!
    I installed E3D V6 at the beginning of this week on a X400 printer (German RepRap). It is a 1,75 mm direct drive version.
    More or less obviously, I faced jamming issues. After analyzing the facts and also reading this topic I came to a conclusion that still need to be checked in practice.
    It appears that V6 is prone to jamming for the following reasons:
    - though it is using a PTFE tube (as a liner, even if it is part of a Bowden), the filament is exposed to the warm region of the cold part of the hotend, for about 1 cm; on certain conditions when more heat accumulates, this may lead to the filament becoming to soft near to the joint with the liner;
    - is not enought to cut the liner square; it must be chamferred to fit the profile of the stainless steel heatbreak, and avoid situation when softened filament will create a frustum that could prevent proper retraction; (this was pointed by triplanedave on Oct 31 before)
    - it is not enough to push the PTFE tube as far as it can go in the heatbreak, but also to lock it, by pulling up the unlocker of the push-fit (this was pointed by josh in his first post in this topic, but I thing it was not taken into account too seriously (as neither documentation is mentioning it); if this is not done, the PTFE tube will easily slide for 1 mm or so in the very beginning and after a while, as pressure builds, the distance may increase allowing for a bulge of soft filament to form between the end of the 2 mm hole in the heatbreak and the end of the PTFE tube; when this happens, the filament will not move anymore in any direction.

    So, leaving apart other causes (like wrong thermistor), I thing the following remedies should apply:
    - E3D should review the design, considering to extend the PTFE lining as near to the heat barrier as mechanically possible (a good engineering example is provided by the construction developed by Adrian Bowyer for the Huxley);
    - The instructions should be revised into saying that the end of the PTFE tube that is to be inserted, has to be chamferred (e.g. using a pencil sharpener); attention should be paid so that the chamfer is equally round, but let a few tenths of mm square, to prevent the edges protruding the 2 mm hole in the heatbreak when pushed against.
    - The instructions should be revised to complete PTFE tube locking in the pushfit (however, this will make difficult if not impossible to retract the tube if needed; this is a design issue, and other solutions could be considered, e,g, using a threaded retainer)

    As said, I'll have to check all of these, but as far as my experience goes, I think they will confirm :)

    L.E. After locking a chamferred tubing for direct drive, check if the filament is passing easily. If not, you can use a long 2 mm drill bit and gently slide it a few times. Then blow inside to eliminate any chip of PTFE that might be captured inside (or you risk a... clog :( )
     
  12. 3Dmaker4U

    3Dmaker4U Member

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    Please watch a short video presenting two simple additional steps to be performed during assembly of E3D V6, that will most probably prevent your filament from jamming.
    http://youtu.be/EeodB0vf9Nk
    All The Best,
    Daniel
     
  13. Inyector

    Inyector Member

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    Good Morning.

    Before yesterday I received the new material. I mounted the nozzle and heaterbreak and now everything seems solved.

    I'm a little unhappy that the previous nozzle could only print 3 hours.

    I hope this lasts longer, now take about 5 hours to print.

    [​IMG]

    Sorry for my bad English.

    Greetings from Spain.
     
  14. BrOncO

    BrOncO New Member

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    hello all.

    First thanks to all for your suggestions and sorry for my bad English

    My story:
    I bought the v6 two months ago mainly to print filaments at high temperature, I printed successfully ABS, PC, nylon , PET.
    the only jamming with these filaments was with a roll of pink abs, this pink does not dissolve completely in acetone, i think is abs+pla, i printed correctly lowering the temperature to 220°C.

    Two weeks ago I started printing pla but i was never able to make long prints without jamming.

    My printer is a Rostock Max v2, ez extruder bowden tube, 1.75mm filament.

    I'm sure that the bowden tube is properly inserted in the v6 and i block the clip with this: http://www.thingiverse.com/thing:24363
    I chamfered the bowden tube as suggested but nothing has changed

    I have two PLA filaments, black and white.
    With black filament could not have more than 2 hours printing without jamming, at 198°C maximum.
    With white filament could not print more than one layer at any temperature.
    The visible difference are that black is more soft and you can bend a little, white filament is very hard and breaks easily when bent. The white filament creates more friction in the bowden tube.

    The first thing I tried was the retraction, but this does not affect the jamming, I tried different lengths, velocities and even disabling it but nothing changed.

    At this point I thought that was not cool enough, I replaced the stock fan with a 40mm but without success, probably the fan duct was not designed well. So I left the stock fan and I put the 40mm fan on the opposite side to blow out air.

    With this configuration, the situation has improved a lot,i can print the black filament at 210°C without jamming (I made 2 seven hours prints without jamming),
    the white filament can print at maximum 200°C but jamming after 1 hour, however, much better than before. :D
    [​IMG]

    I believe that with a best cooling system the situation should improve.
    the best thing would be to increase the surface of the bottom fins , but I do not know if it is feasible, it is simpler to use two or three fans.

    when I have some time I'll try to print a fan duct for 2 or 3 fan.
     
  15. 3Dmaker4U

    3Dmaker4U Member

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    The main issue is unfortunately a design issue.
    V6 has the upper part of the heat-break M7. Compared to V5, there is an additional 0.5 mm stainless steel all around the filament, until it gets to the bowden.
    Stainless steel is very bad as thermal conductor. Hence with V6 cooling is worse than with V5.
    As I said, a solution would be to allow the bowden lower in the heat break. It will act as thermal insulation.
    Obviously, one could enforce better air flow, hence improving cooling, but this would mean additional weight on the moving parts, which is not desirable.
     
  16. TaurusSilver03

    TaurusSilver03 New Member

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    Just installed this week and it always jams. Every time I pull it out it looks like the pic. Seems the small part before it melts is the exact measurement like the space between the heat block and heat break. Anyone knows what causes this?
     
  17. cantax

    cantax Member

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    Thank you Aggresive. That solved my PLA-Jamming-Issue.
    I drilled my noozle from 3.2mm to 3.4mm. My Heatbreak is 3.5mm at the hotend, like yours. I can't feel any resistence even after 10 min idle while the Extruder is heated.

    Although, i recommend to use a hobbed bolt in your extruder that grips the filament really tight. I need to "sharpen" mine a bit because the E3Dv6 seems to need a bit more pressure if you dont want to raise your temperature to get it flow better.

    I need to say it, i am bit disappointed about the accuracy of the heatbreak. Remember, that you are selling one of the more expensive Hotends. Its not that much to ask for getting a hole in the heatbreak thats tha same size going in and going out of it. At least 0.1mm isnt too much accuracy to accomplish.
     
  18. abillionhorses

    abillionhorses New Member

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    Cheers byramamdaimee! This was exactly what my problem was and almost exactly what I went through to solve it as well. Ended up using a torch to clear the clog. Checked out virtually every square millimeter throughout the whole hotend, unfortunately, before realizing what was going on...ALL GOOD NOW THOUGH :)
     
  19. grpiotr

    grpiotr Member

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    Hey,

    Have anyone ever had problem like in attached picture?

    It occurs mostly on PLA (1.75mm) with my brand new (today installed e3d v6). I did everything like in here http://e3d-online.com/E3D-v6-Assembly.
     
  20. cantax

    cantax Member

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    @grpiotr: Most likely your extruder slips on the filament. Try to calibrate your E-Steps.
    For PLA set the temperature to 235°C. Extrude 20mm (should be enough for now). Check if you actually extrude 20mm.
    I think the result will be (nearly) 20mm. Now, lower the temp in 10-15°C Steps and extrude again.
    If i am right and your extruder slips on the filament you will now see, that with lower temp your Extruder travels less than 20mm although you told it to extrude 20mm.
    Solution: a) get a better hobbed bolt that grips the filament really good.
    b) tune your existing Bolt/Pulley.
    c) tighten the spring on your Extruder to get a better grip of the filament.
     

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