PLA Not Sticking to Blue Tape

I'm trying to use Scotch #2090 blue tape with PLA, and the PLA refuses to stick. Why? I do not have a heated bed.

Also, I get a constant stream ooze which does not stop even if I run the extruder in reverse (Wade). What would cause this?

HI..

Sounds like you have the temp on the PLA set too high, it should be about 180/190 C..

As for getting it to stick, make sure the nozzle is sey set to one sheet of paper above, as in so you can JUST slip ones sheet of paper between the print bed and the nozzle.. Why, if you print with a .4mm layer by setting it so low it will stick to the bed as it squeezes out the plastic at .1mm ..

If all else fails get a headed bed..

Auzze


krunchy Wrote:
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> I'm trying to use Scotch #2090 blue tape with PLA,
> and the PLA refuses to stick. Why? I do not have
> a heated bed.
>
> Also, I get a constant stream ooze which does not
> stop even if I run the extruder in reverse (Wade).
> What would cause this?

I will give that a try. I had read somewhere that the nozzle should be 2-3 mm above the bed, but I guess that was wrong.

Edited 2 time(s). Last edit at 09/04/2011 08:28AM by krunchy.

Ideally it should be exactly the layer height above the bed. With PLA on blue tape it needs to be a bit lower to stick but that leaves a ridge around the base of the object.

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[www.hydraraptor.blogspot.com]

If you are using skeinforge, the first layer is printed at 1/2 your layer thickness. If you have raft enabled and have it set to not print out a raft (base layers = 0 & interface layers = 0) then the first layer is at:

(operating nozzle lift over layer thickness + 0.5) * layer thickness

So if layer thickness is 0.4mm and operating nozzle lift over layer thickness is 1.0 the first layer is printed at 0.6mm.
(this assumes bottom isn't enabled).

Now that I'm a few months into printing, what I found works best so far is wiping down a new layer of blue tape down with some rubbing alcohol. I can usually get about 8-10 prints off the same tape before it stops sticking... Sometimes I find that the adhesion is TOO good, and the tape will rip when I try to pry the object off, but even then, as long as I can lay it back down, it works just fine.