1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Unanswered Part cooling fan configuration.

Discussion in 'Troubleshooting' started by Oisin, Oct 25, 2016.

  1. danzca6

    danzca6 Well-Known Member

    Joined:
    Jul 27, 2015
    Messages:
    2,161
    Likes Received:
    1,077
  2. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    Thanks for the picture, Danzca. I've got the IR sensor mounted on the side now. Probably a good call covering the sensor since some stray piece of plastic from a failed print getting hooked on that could destroy it. I only found the mount on thingiverse though, not the cover.

    About the fan mounts. I plan on using 50 X 20mm fans. They may not fit in that configuration but I could give it a go. I'll try to find mounts like that that will accommodate a 50mm fan. If you already know of one then I'd appreciate it.
     
  3. danzca6

    danzca6 Well-Known Member

    Joined:
    Jul 27, 2015
    Messages:
    2,161
    Likes Received:
    1,077
    50's are going to be tough to find. 40's are the norm I see. There are 40x10 and 40x20 fan mounts.

    I designed my mount from scratch to incorporate the cover. It isn't adjustable for the extra length of the V6. So I would need to tweak it and is in Tinkercad. I've been meaning to port it over to Fusion 360 but haven't had the time.
     
  4. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    Would a 125% scale and a drill turn your mounts in to 50mm mounts?
     
  5. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    So the next test I did was mounting my old 40mm X 40mm X 10mm fans back on the printer. Dual shrouds the same as before. Here is the overhang result. Not much different really. Starts to get pretty poor at only 35 degrees.
     

    Attached Files:

  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    You need to set a minimum print time per layer to allow the fan to have a chance to cool the layer once it get towards the top of the print and the layer print times get ... small. Without that set the printer will be printing on top of filament laid down and not yet cool.

    I can give you directions for setting that parameter in Simplify3D. I don't use the other slicers, however I am sure they all have it somewhere.
     
    jim3Dbot, Geof and danzca6 like this.
  7. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    Okay I see. I only use Simplify as well. You think that could entirely resolve the issue? Or are better fans necessary?
     
  8. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,729
    Likes Received:
    2,330
    Its possible your fan ducts arnt hitting the part the way they should.
    My minimum layer time is 25 sec i think. Any faster and it was yo fast for small parts
     
  9. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,729
    Likes Received:
    2,330
    I rub dual cooling fans ducted and to bw honest my printing temp was the biggest issue. I was to high on my temps and the fans couldnt keep up
     
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    It would certainly remove the issue I see in you prints where the top layers are getting laid down too hot. It won't cure world hunger or anything...
     
  11. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    I'm printing at 190C. I could go to 180C and try it out. Any lower and I'll have to change the 'cold extrusion' settings in the firmware. The airflow coming from the ducts isn't really that good to be honest. No better than when I had a single 50 X 20mm fan. I'll retry with a higher minimum layer time.
     
  12. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    I do not have dual fans on either of my Robos and this is not an issue. One does have a ducted fan, but the other is the stock fan and mount. They both work fine by simply controlling the layer print times. Pick a number that is reasonable for a minimum print time and the small layers will have a chance to cool down before the extruder comes back over them. Huge difference in quality.
     
  13. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    Okay Mark. Could you tell me where it is in the Process settings? Also, what are your retraction settings? Just to compare.

    Mine are the following; In the 'Extruder' tab:
    retraction distance = 0.8mm,
    retraction speed = 150mm/s.

    And then in the 'Advanced' tab I've checked

    'Only retract when crossing open spaces',
    'Force retraction between layers',
    'Min travel for retraction = 5.00mm',
    'Only wipe extruder for outer-most perimeters'.
     
  14. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    My retraction settings for every filament type except nylon is the defaults. Never had an issue there.

    The other is under the COOLING tab, SPEED OVERRIDES. More details can be had in their tutorials.

    The best settings for you depend a lot on how you print so you need to do a little experimenting.
    For PLA and the like I want at least a 45 second layer print time and for some it is a bit higher.
     
    #34 mark tomlinson, Oct 27, 2016
    Last edited: Oct 27, 2016
  15. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    P.S. if you are using Simlpify3D and you have NOT gone through their online tutorials you are seriously missing out.
     
  16. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    Okay thank you. I have set it to 25 seconds and 25% allowable speed reduction. I'll see what effect that has now.

    I have taken a look at the tutorials on their site :) I'll look at some other ones on Youtube.
     
  17. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    It make sense if you think about it. The filament you lay down has to be solid before the extruder makes another pass over it with more filament. The first print I saw this on was a test pyramid I was doing. The top was crap the rest was perfect :)

    How each slicer handles this setting is different. Some just slow down the print speed while others will actually just move the extruder aside and wait for the time to expire before resuming the next layer.
     
  18. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    It definitely does make sense. However surely having the 'random start points' turned on as well as '25 seconds minimum' for each layer means one negates the other to an extent? The random point might begin where the printer just finished printing?

    I'm printing the part now and it doesn't appear to be taking any longer. Maybe I'll notice the difference when the overhang part begins.

    When I look at Octoprint it says each layer takes 2 minutes and 53 seconds anyway.
     
    #38 Oisin, Oct 27, 2016
    Last edited: Oct 27, 2016
  19. Oisin

    Oisin Member

    Joined:
    Apr 14, 2015
    Messages:
    384
    Likes Received:
    23
    So the curl was evident even in the first few layers. I'll try having my fans on from Layer 1 and maybe printing at 175 or 180C
     

    Attached Files:

  20. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,668
    Likes Received:
    7,316
    The time is for the layer, not each point :)
    Hopefully the slicer is smart enough to avoid something like that.
     

Share This Page