Monday, November 14, 2011

Nozzles With Heat Chambers Improve Print Speed

The special nozzles, with heat chambers, have been shown to be an improvement.  100mm/min print speeds have been obtained with PLA by having a heat chamber that is approximately 12mm long.  Without the heat chamber, the print speed was much less than 70mm/min.

In the near future, all J-Head nozzles will be shipped with heat chambers.


  1. But can they print slowly still? My first hotend had a small chamber in it and I could never print slowly because it oozed a lot.

  2. I am printing with PLA at 90mm/min using your MkIII-b hotend without problems. I will try 100mm/min and will let you know the results.

  3. 100mm/min is very slow, surely you mean 100mm/s ?

  4. I mean 100mm/min, meaning feeding 10cm of 3mm filament a minute through my extruder, so 1.67 mm a second.
    If I could feed my extruder 10 centimetres a second I would be very happy (if you can I would like to see a video and praise you).

    I just tried to print with PLA at 100 mm/min and it worked well, didn't have any problems. It was only a small test print, but I will continue to print at this speed.

  5. I see, you are talking about input rate rather than output rate / print speed.

  6. I am using Pronterface / Skeinforge 44 where (I think) this is standard? I think there are many people using Skeinforge 41+ who tend to say mm/s where they mean mm/min of filament.

    When I extrude 50mm of filament in pronterface at 100mm/min it takes 30 seconds and indeed 5cm of filament is extruded (measured and timed it just to be extra sure...).

    When you say 100mm/s, do you mean 100mm length output a second? I think the best way to measure is the amount of extruded volume a minute (or second) so it doesn't matter if you have .5 or a .35 nozzle.
    Can you tell me how this output rate / print speed is calculated so we can make a good comparison?

  7. Above I mean:
    When I extrude 50mm of filament in pronterface at 100mm/min it takes 30 seconds and indeed 5cm of input filament is extruded (measured and timed it just to be extra sure...).

  8. @maakit
    If that is your max speed I think you have an issue. When I change filament I purge my extruder with G1 E200 F900 . That's 600mm/m or 10mm/s of 3mm filament going into the hotend. It streams out of my 0.35mm nozzle at 38400mm/m or 640mm/s.

    I can run it at F300 continuously without it running out of molten plastic.

  9. Oops that was supposed to say G1 E200 F600

  10. You're right about the mm/s mm/min I think.
    In Skeinforge I have 100mm/sec feed rate and 100 float rate.
    If I look at my GCode I am puzzled... It gives G1 commands with F6000 (six thousand) which can't be right... see below.

    G1 F3600.0
    M108 S100.0
    G1 X94.983 Y106.102 Z0.35 F6000.0 E23.172
    G1 X94.142 Y106.102 E23.2005
    G1 X96.102 Y104.142 E23.2942
    G1 X96.102 Y103.3 E23.3227

  11. ok, I see F6000 gives the speed for the x-y move and extrudes an absolute amount of filament during that move. So from the first G1 move to the second it moves .841mm in the x direction while extruding .0285 mm of input filament. It moves in xy direction at 100mm/s (6000mm/min) so the extrusion speed is 203 mm/min

    G1 X94.837 Y93.898 E40.909
    G1 X95.679 Y93.898 E40.9374
    moves in x dir .842mm extruding .0284mm
    extruder speed is 202 mm/min input filament

    G1 X71.103 Y45.164 E537.7794
    G1 X46.398 Y69.868 E538.961
    moves in xy dir 34.94mm extruding 1.1816mm
    extruder speed is 202mm/min input filament

    G1 X46.398 Y119.514 E678.0336
    G1 X120.749 Y45.164 E681.5897
    moves in xy dir 105.15mm extruding 3.5561mm
    extruder speed is 203mm/min of input filament

    @reifsnyderb: sorry for these off-topic posts...