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bingobob

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Posts posted by bingobob

  1. I never have good results with retraction. I prefer cleaning up the mess afterwards or it tends to under or over-extrude at critical points.

    Another source of your problem could be that with multiple needles, the layers have much longer to cool down between successive writes. Maybe you could try enclosing and heating the inside of the ultimaker to prevent layer temps dropping too much.

     

  2. I personally think it's pretty suspicious that there is no trial version of the Netfabb software for ultimaker. No way I'd spend money on a product with such ambivalent reviews without being able to try it first.

    Reading this thread is the nail in the coffin, as far as I'm concerned.

    Cura is OK. The only thing I liked the look of in Netfabb was the support structure. The one in Cura is too inflexible and I just end up designing my own support structures into the model.

     

  3. I am also very unhappy with 14.01. On some retractions pulls back the Ultimaker too much. This means that afterwards material is missing. This looks like under-extraction. I have some prints so lost.

    Edit: my workaround: back to 13.12 and everything works as usual

     

    Did you upgrade the firmware, though? Or are you using the firmware from 14.01 with 13.12? Looks like I am having the same issue as you.

     

  4. I just upgraded to Cura 14.01. Did the firmware upgrade.

    I loaded my model, pressed print and a blank window with the title "Printing" comes up and that's it. Nothing happens. Am I missing something?

    In the meantime, I'm going back to Cura 13.04 - I hope it still works.

    Thanks.

    /edit: In the end I force the window to close and it tells me that Pythonw.exe was non-responsive.

     

  5. It looks like it doesn't like that overhang at all.

    And there's some major warping going on on your first layer.

    That raft is huge. By the time the print head has finished with it, it'll have changed temperatures several times if you're using a heated bed. Have you tried printing directly onto the kapton tape with ABS glue and no bed heating at all?

    What is your head speed? What results do you get if you use my settings?

    Can you post your printing parameters?

     

  6. Spend some time getting the bed level. First you need to know if your glass is flat. Just use a ruler or something to see if is or not. If not, then you'll never get a good print over a large area like that.

    Have a level bed is essential in getting a good first layer. If the bed is too low then the ABS will blob and the head will push it around. That looks like what has happened in your print.

  7. No, I just grab the sleeve that connects the motor to the screw and turn it with my fingers. Once it's adjusted for the first layer, you don't have to touch it after that.

    How flat is your glass? Have you put a straight edge on it? The first bit I used was completely bent in every direction. I went and bought some 4mm stuff that was perfectly flat.

  8. What does your very first layer look like? It looks like it might be starting to print too far above the bed. If the first layer isn't good then the rest will fail. I always print a double skirt around the object and while it's printing that I manually turn the Z-axis so that the first layer is being pressed solidly into the bed. I raise the bed too far and it stops extruding (no space to extrude) then lower is slightly so that the line it is printing is nice and flat, not like a bead.

    I don't understand why yours is blobbing like that. Are you using some odd ABS? Looks fluorescent in your photos. Maybe the dye is causing different behaviour.

  9. Are you using cooling? If so, try not cooling. I get poor layer adhesion if I cool too quickly - or at all.

    You could also try printing at a higher temperature, with a slower head speed. Maybe increase the amount that is extruded by lowering the value of the filament diameter.

  10. Good to know. Thanks. :)

    I much prefer the mechanical properties of ABS to PLA. I find that the layers bond better, too. Plus you can finish the surface reasonably nicely, depending on the part you want.

    I have also found that for long flat parts like the one you describe you can print directly onto the glass with the ABS goo. It doesn't stick as well as on Kapton, but you get a beautiful mirror finish to the bottom layer from the glass.

    I don't have any heat control on my PCB. I need to wire something up. At the moment it's all or nothing. What do you use to control the temp?

    Thanks.

  11. It's physically unplugged.

    Even with very low fan speeds, there is a large amount of warping and cracking between layers.

    I think by not cooling and printing relatively slowly the material remains at its glass transition temp longer and kind of self-anneals if that makes any sense.

    I think the cooling depends a lot of what kind of part you are printing. When I printed the thin-shelled ABS fan duct (see above) I used cooling and that printed just fine.

    I still haven't really got my head around the science of it. The only thing I can think of left to try is enclosing the print volume and heating it to keep the temp inside at 70°C+. Not sure how the motors and belts will like that, though.

  12. I'm still experimenting, but the best results I have had so far are with these parameters:

     


    [profile]
    filament_diameter = 2.97
    nozzle_size = 0.4
    wall_thickness = 0.8
    retraction_enable = True
    layer_height = 0.1
    solid_layer_thickness = 0.8
    fill_density = 100
    print_speed = 50
    print_temperature = 255
    print_bed_temperature = 70
    support = None
    enable_raft = False
    filament_density = 0.88
    skirt_line_count = 2
    skirt_gap = 4
    retraction_min_travel = 2
    retraction_speed = 30
    retraction_amount = 2
    retraction_extra = 0.0
    travel_speed = 100
    max_z_speed = 3
    bottom_layer_speed = 30
    cool_min_layer_time = 15
    fan_enabled = True
    bottom_thickness = 0
    object_sink = 0.0
    enable_skin = False
    plugin_config = (lp1
    .
    model_matrix = 3.74939945666e-33,1.0,-1.22464679915e-16,1.0,3.74939945666e-33,6.12323399574e-17,6.12323399574e-17,-1.22464679915e-16,-1.0
    extra_base_wall_thickness = 0.0
    cool_min_feedrate = 10
    fan_layer = 1
    fan_speed = 20
    fan_speed_max = 40
    raft_margin = 5
    raft_base_material_amount = 100
    raft_interface_material_amount = 100
    support_rate = 100
    support_distance = 0.5
    infill_type = Line
    solid_top = True
    fill_overlap = 15
    bridge_speed = 80
    sequence = Infill > Loops > Perimeter
    force_first_layer_sequence = True
    joris = False
    retract_on_jumps_only = True
    hop_on_move = False
    Crucially, the preliminary process is this:

    1. Paint kapton tape with ABS goo

    2. Let dry

    3. Preheat platform

    4. Start printing the first layer (this is the solid raft that I add in CAD - see above)

    5. As soon as the raft has finished printing (sooner even, if possible) turn the heating off

    Let the printer print.

    And most importantly - no cooling fan.

  13. Thanks for that, but my problem is not getting the parts to stick to the bed. In fact with the heated bed, the Kapton tape and the ABS goo the problem is getting the part off the bed afterwards!

    My problem was the deformation at different levels.

    I have made significant progress in this and the other problems I was having printing ABS and I am now much more confident about printing in ABS. More so than PLA which I have noticed also shows similar deformation, albeit less significant that in ABS.

    Here is the above part printing correctly now:

    correctlyprinting.jpg

    The finished print:

    finishedbrut.jpg

    And the smoothed finished product:

    finishedsmoothed.jpg

    This is a PLA print showing deformation:

    photo2cftb.jpg

  14. OK, that print above turned out like this:

    photo1bst.jpg

    The warping in the support structure wasn't limited to the support structure, but you can see where the wall of the cylinder has pulled in.

    I printed this part again but instead of having a fill ratio of 20% I used 100% and the the print was MUCH better. Much less deformation. Even on the support structure which is a bit odd.

    I realised that the support structure on the right was more deformed than on the left and I realised it was due to the standard fan ducting which blows more air to that side of the print (the nozzle not being centered on the fan) so I have printed out a new duct that is much more directional to see if that helps:

    photo2rd.jpg

  15. Thanks to mrjohnk's post of his ABS printing parameters in this thread:

     

    http://umforum.ultimaker.com/index.php?/topic/1789-retraction-and-blobs/

     

    I was able to print an object in ABS that is the most successful that I have so far achieved.

     

    I think it's worth repeating those parameters here for anyone struggling to print in ABS. I was experiencing a lot of blobbing, cracking and warping and thanks to those parameters, the first 2 at least are greatly improved.

     

    I was getting a lot of failed prints from the first layer coming unstuck, but by not using the Cura raft and printing a solid 0.3mm base instead they seem to be sticking better.

     

    Most of my problems come from Cura's support structure which I don't like. Here is an example:

     

    photo1aue.jpg

     

    Anyone know what causes this?

     

    Sometimes this causes the print to fail (head picks up on the print and wipes it out). I don't really see a solution to this other than provide my own support structures in CAD.

     

     

    Print looking good now. Updated to latest Marlin and changed settings. Thanks for the help. Link to pic below. Also changed the order of print to Perimeter > Infill > Loops in order to drop any potential blobs in the infill instead.

     

    http://www.flickr.com/photos/8465641@N07/8581931440/in/photostream

     

    [profile]

    layer_height = 0.2

    nozzle_size = 0.4

    wall_thickness = .4

    solid_layer_thickness = 0.4

    fill_density = 20

    skirt_line_count = 6

    skirt_gap = 0

    print_speed = 50

    print_temperature = 255

    support = Everywhere

    enable_raft = False

    filament_diameter = 2.97

    filament_density = .92

    machine_center_x = 100

    machine_center_y = 100

    retraction_min_travel = 2

    retraction_speed = 30

    retraction_amount = 3

    retraction_extra = 0

    travel_speed = 150

    max_z_speed = 3.0

    bottom_layer_speed = 40

    cool_min_layer_time = 15

    fan_enabled = True

    bottom_thickness = 0

    enable_skin = True

    model_scale = 1.0

    model_rotate_base = 0

    flip_x = False

    flip_y = False

    flip_z = False

    swap_xz = False

    swap_yz = False

    extra_base_wall_thickness = 0.0

    cool_min_feedrate = 20

    fan_layer = 1

    fan_speed = 17

    fan_speed_max = 75

    raft_margin = 5

    raft_base_material_amount = 100

    raft_interface_material_amount = 100

    support_rate = 25

    support_distance = 0.5

    infill_type = Line

    solid_top = True

    fill_overlap = 12

    bridge_speed = 100

    sequence = Perimeter > Infill > Loops

    force_first_layer_sequence = False

    joris = False

    retract_on_jumps_only = True

    enable_dwindle = False

    dwindle_pent_up_volume = 0.4

    dwindle_slowdown_volume = 5.0

    retraction_enable = True

    plugin_config =

    hop_on_move = False

    model_matrix = 1.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,1.0

    object_sink = 0.0

     

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