Can't get 0.6mm or 0.8mm nozzles working on E3D-V6

Discussion in 'E3D-v6 and Lite6' started by moo10032, Feb 7, 2015.

  1. moo10032

    moo10032 Member

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    I just got my E3D-V6 1.75mm direct hooked up and I can't get 0.6mm or 0.8mm nozzles to print hardly anything reliably... I have to slow down to around 10mm/s for anything to print with the 0.8mm nozzle on which is pretty ridiculously slow. Is this just how fast the V6 can keep up with heating ABS with that large of a nozzle? IF so why do they even sell the 0.8mm with this.

    With the 0.6mm nozzle I have to stay under around 20-30mm/s TOPS. The only reason I bought this was because bigger nozzle should have meant faster speeds. It seems the hotend can't keep up. It is not my stepper or gear drive because even by hand it is hard to push any large amount of plastic through the hotend. Pretty disappointing after dumping 100$ into this.

    I reseated the thermistor several times and it measures with an infrared thermometer I have, the nozzle is always around 50C below what the thermistor reads. Even if I bump the temp all the way up to 300C it doesn't seem to help the ABS flow any faster.

    Could there be some fault with the entire hotend? Really need some help here to get this working better.
     
  2. elmoret

    elmoret Administrator

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    I would say the fault lies not with the hotend, but perhaps with your understanding of how hotends work and to a lesser degree the tools/filament you are using. Lets get started on fixing that:

    - IR thermometers cannot be used to reliably measure the temperatures of reflective metals. Simplified, they end up measuring an average of room temperature and the metal itself, since some of the radiation absorbed by the sensor is reflected room radiation off the metallic nozzle.

    - Flowrate = feedrate * 2pi * r^2. So with a 0.4mm nozzle:

    60mm/s * 6.28 * 0.2^2 = 15 mm^3/sec

    30mm/s * 6.28 * 0.3^2 = 17 mm^3/sec

    15mm/s * 6.28 * 0.4^2 = 15mm^3/sec

    So the 0.6mm nozzle at half the speed actually moves more material than the 0.4mm nozzle moving twice as fast.

    You are being limited by how large the melt zone area is. If you want to complete prints even faster, that's what the Volcano is for - it doubles the melt zone's length.

    With that said, I have no problems printing at 60mm/sec through a 0.8mm nozzle, regular v6 (non-Volcano). I would say your ABS filament is a bit crap, and doesn't have good MFI specifications.
     
  3. moo10032

    moo10032 Member

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    That all makes a lot of sense, I'm just not understanding how you can get up to 60mm/s with 0.8. I've been using hatchbox filament from amazon and it appears to be really good stuff, always smooth, strong and clean prints with the 0.4. I just don't see how the filament quality would add 50mm/s for me. What temperatures do you print at, what is your extruder setup like?
     
  4. elmoret

    elmoret Administrator

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    Smooth and strong doesn't mean it has good MFI (which is a measure of its ability to flow). I print at 260C with Sabic MG94 resin I extrude into filament with a Filastruder.
     
  5. moo10032

    moo10032 Member

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    What is a equivalent brand of already made filament? I can't find any MFI ratings on any filament around the web.

    In your experience if I switched to the Volcano how much of a difference would I actually see with the same filament I'm using now?

    Do you know if the Volcano will ever offer a 0.4mm nozzle? That was the only reason I ended up getting the normal V6.
     
  6. elmoret

    elmoret Administrator

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    There are definitely suppliers of MG94 filament, have you tried a search?

    https://www.google.com/search?q=mg94+abs+filament

    Volcano results print speeds 1.5-2.0x that of v6, assuming all else is equal (temperature, nozzle diameter).

    Why would you want a 0.4mm nozzle with a Volcano? Doesn't make any sense. 0.4mm nozzle flowrates are best matched with the melt zone provided by a v6 heat block.
     
  7. moo10032

    moo10032 Member

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    O whoops I was searching for "MFI filament" still pretty new to printing =P

    Having to swap out heating blocks seems like a pain then just swapping out the nozzle. I can see myself breaking the heat break with swapping them in and out so often but I guess I need to.

    I need the 0.4 nozzle to print out gear teeth, and the larger nozzles to print the large components to things.

    I will try out some of this kind of filament. Thanks for the help.
     

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