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I have just finished assembling a TT I3, with a large heated bed 220x280, a couple of weeks ago and my first print went well.

After a few initial experiments I noticed that the filament will not stick. I have manually leveled the bed over and over again, added a glass sheet over the bed, applied masking-tape and what-not.

The filament still will not stick, it will curl up on the nozzle, clog the nozzle and all sorts of other issues...

Everything functions properly but it seems like the extruder is trying to push more then the nozzle is actually putting out. My filament is 1.75 mm.

Can anyone help with all this so I can get something printed decently?

I am printing with PLA, I started off with 50 °C, raised it to 60 °C, and last time I tried to print a filament spool holder with 70 °C (twice), still if layer is thin it will not stick.

After cleaning the bed with alcohol 70%, you can see the issue in these videos:

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  • $\begingroup$ That temp sounds about right for PLA.. Are you cleaning the print bed with acetone/windex before printing? Just the traces of oils from your hands will keep the plastic from sticking. $\endgroup$ – ctag Sep 15 '17 at 12:08
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    $\begingroup$ I actually just learned this myself, but isopropyl alcohol may not be the best for cleaning print beds, as it can leave residue. I switched to acetone a few days ago and saw a noticeable improvement. $\endgroup$ – ctag Sep 16 '17 at 15:57
  • $\begingroup$ Additionally, it does look like the first layer is thinner than it should be. You want to squish the plastic down to get good adhesion to the plate, but there should still be a bead shape. $\endgroup$ – ctag Sep 16 '17 at 15:58
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    $\begingroup$ Unfortunately, up to now, no answers are given on your question! Have you found an answer yourself? If so, you may add your own solution and accept that after 48 hours. If you have not been able to address the problem please update your question so other people may help you find an answer. You can even decide to delete the question. We need to reduce the unanswered questions list to graduate from the Beta stage. $\endgroup$ – 0scar Sep 7 '18 at 6:45
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Getting that first layer to stick is sometimes pretty hard, you just need to find a good combination of settings. Clearly your filament does not stick too well as the brim comes off after been laid down after a while.

Parameters that affect adhesion are:

  • Bed temperature; a temperature close to the glass temperature is favorable as the filament is soft at that temperature, the stresses are low due to this softness and the smaller temperature difference. You already tried to increase bed temperature: 50 - 60 °C should be fine for PLA, there is no need to go higher than 60 °C,
  • Hotend temperature; the temperature of the filament deposition could be increased for the initial layer, usually a 5 °C increase over the standard temperature should be enough,
  • Overextrusion; a small over-extrusion on the first layer (filament flow scale factor larger than 100 %) could sometimes help to better adhere the first layer, but usually this means that the nozzle to bed distance is too large,
  • Correct leveling and correct nozzle to bed distance; level the bed as good as possible or scan the bed and use mesh leveling if the build platform does not have a uniform (flat) shape, also make sure the distance between the nozzle is correct: too small or too big cause the filament not to stick very well.
  • Debris in nozzle; debris in nozzle can cause non-uniform extrusion, cleaning the nozzle with the atomic method (heating up the nozzle, inserting filament, cooling down the nozzle and finally yanking out the filament cleaning all the cooked stuff inside),
  • Cleanness of the bed; make sure the bed is not greasy,
  • Tack of the bed; the use of a PVA based substance on the bed like e.g. gluestick, hairspray or specific printer sprays like 3DLAC increase the bed adhesion considerably,
  • Bed preparation; sanding the bed to roughen the platform, using tape, etc. are all tricks to get the filament to stick better.

Either one of the suggested parameters or a selection of these are the answer to your question, just figure out what works best for your printer.

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