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deepshots

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Posts posted by deepshots

  1. I've had similar issues with "roofing" and here's my solution.

    1. Get a new coupler.. well actually get a bag of them. My underextrusion issues dissappear once I change a new coupler... The old ones are always hollowed out from inside and burned.

    2. For difficult surface closings I drop down the temperature to a miniumin where it still comes out nicely and put fans to 100%. I also lower the build plate a bit manually on the fly. This way the nozzle doesn't travel against the uneven surface and end up scraping the previous layer and destroying the new one. Rather it cools down on top nicely as a string which then gives a great support for the next layers. On 0.1 I usually do 0.8 tops and bottoms. For a nice finnish I rise the buildplate again (for last 2 layers ) to get a really nice "squeezed" surface.

    I know its lots to do but that's often the only way to get good surface quality on UM2.

  2. I have had UM2 for over a year now and I use it mostly for printing gears and other knick-knacks from PLA/PHA for my customers. But I see the print quality slowly deteriorating over the last half an year. There seems to be nothing wrong with the printer and I get 10/10 from the UM2 speed torture test but still the print quality is not what it used to be: More banding, more underextrusion (especially with thicker layers), not as accurate dimensions, etc... So I was thinking to buy another new one as I can't be in a position when I don't have a working printer financially.

    My parts are small so the UM2 Go seems like a good option. The only problem with it is the lack of the heated bed. I have never printed without heated bed. I have never had any adhesion issues while the bed is hot. My prints pop out often themselves once the bed is completely cooled. I can't see how could the prints adhere to a cold bed. Do they?

  3. One thing I just realised that makes the new "forum" seem so un-forumy is the lack of activity counter. Post count and the latest reply time stamp is an old and proven method of quickly seeing what part of the forum is active and what not. On the forum overview please add post count and latest reply after each of the boards... and who posted it.

  4. I have sometimes heard the "clack" also and had to wriggle the tube to get the filament in. Now I always sharpen the filament edge. No issues since that. and I get 10/10 from the speed torture extruding test so I don't think my coupler is especially deformed to restrict the movement.

     

  5. I used to print PLA without glue but I have started to use it recently for sharp cornered bottom layers. (I usually print gears where the teething start from the first layer) Without the glue, when laying down the first layer, it seems like the sharp corners of the teeth sometimes curl/or are being pulled up by the nozzle when it passes. Happens only in the first crucial layer. I've always thought that the first layer filament strings does not grip well on the clean glass. Glued surface feel more rough once dried and my corners don't curl up.

    (note I'm talking only about the initial layer only... not to be confused by other types of corners pulling up)

     

  6. I've had this same issue for ages. My trick is to really slow down to crawling speeds for the final 2 layers and rise temperature a bit plus turn the three screws leveling screws so that the final layers really squeeze on the print. (sometimes I just lift the build plate by hand and keep it there for the final layer)

    Not ideal but that's the only way I've managed to solve this.

    I should say that the gaps seem to be worse when on 0.2mm

     

  7. ref: a couple indents

    I always get these and I've always thought that they are due the softened filament stretching when you are pulling it. They wary from every pull. I've had no issues due the "stretch marks".

     

  8. I'm assuming that you are using "move material" here. You really giving it a proper shove inside the head. The motor skips because there is just too much "pressure" at the hotend.

    When I use "move material" I generally give it 3-4 clicks at the time and then wait few seconds and then another 3-4 clicks... etc... If I do more more the extruder will shred the filament. Even at this "3 clicks/wait/3 clicks/wait speed" the flow out from the head is nice and constant.

    Try to feed the cord in to the printhead manually and you will get sort of a feeling how little pressure is actually needed for nice flow.

     

  9. Further results on the ongoing fur saga.

    I currently print with Colorfabb PLA/PHA and CO-Polyester XT. (not at the same time of course :mrgreen: )

    PLA/PHA: 0.1 layers, Speed 50, temp 200, bed 60 = Not a single hair

    Swap to XT: 0.1 layers, Speed 50, temp 240, bed 70 = Fur everywhere.

    No matter how clean or dirty my nozzle is XT makes fur and PLA don't. It must be either the material difference or as gr5 said the higher temperature. Over the last month I have probably swapped the material for at least 10 times and it just keeps happening.

    I might contact Colorfabb and ask what they think.

     

  10. Is there anything out there for UM2 that would allow me to slice/print part of an object with 100% fill and other parts less? In one go... related to Z would be enough.

    I've tried to achieve this in CAD also but of course the final STL will always be just "hollow"

     

  11. I've peered through my nozzle and it seems perfect. The hole is nice and round and atomic pulls do not result to anything. However, I might have a tiny scratch just outside the nozzle end (i've looked it at with a magnifying glass). I have often wondered if that is a reason for my priming curls.

    And I could imagine that the little scratch could be a like a sharp comb that makes the hair happen. But all this is just guesswork

     

  12. I should add that since beginning my UM2, when priming, curls the extruded filament on the nozzle if I don't yank it down gently. After the first bit gravity will take care of the rest. I've done this routinely for a half a year now. If I don't do it result is a mess. But as said earlier, my printer has always done perfect quality before this fur issue started some weeks ago.

     

  13. I've not got any conclusive results unfortunately... Yesterday I started with a new roll of Colourfabb PLA and no fur at all. My worst fur came from a XT sample material I got from Colourfabb at London 3D print show. I wonder if this material had something wrong with it. I was about to change the nozzle but now it looks like I don't have to.. oh well... at least I have a spare

    Also I have started to think that bed being too near could cause this. Maybe the hot nozzle rubs the previous layers and pulls tiny strings of it....

    I'll do more tests with a new roll of XT that I just got if the fur returns.

     

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