Tricks to avoid warping?

[greengecko 8]

Hi,

I still was not able to resource all things needed for a heated bed and I still have sometimes problems with warping/bending of the lower parts from the blue tape (printing PLA with 200 degree).

What are the best hacks to avoid bending/warping of PLA (especially when printed with 100% infill and big prints stretched over the whole plattform?

Lower temperature?

Additional layer of blue tape?

Somehow modifying the blue tape (aceton wipe??)

Lowering the height of the first layer more into the blue tape?

Using a raft?

I know the only long term solution is a heated bed. But it turned out to be not too easy to find a tempered glass of the right size in Canberra (almost there, with even holes for fixing it to location of the original bed).

Unyil then, any advice is highly appreciated. I would be happy to extend the wiki if there are any agreed suggestions.

[fluxline 0]

I would just add to the list, just things I've tried that have both worked ... and not.

- with the 2 layers of blue tape, wipe down the first layer with acetone/alcohol and let dry before putting on the second layer. also, make sure that whatever you wipe down with is not from your wife/girlfriends stash, both often have some oils in them.

- put the layer that the fan turns on at layer 2 or 3 instead of 1. I actually pointed a halogen light at the print while printing and then turned it off after about 10 layers. others with more experience might comment on if this actually helped or not but i got my print and cold have been just luck.

[futurejames 0]

I tried the two layers of tape + wipe with acetone, I was amazed at how well it stayed straight on the bottom layer. I deliberately printed something that previously warped like crazy, to the point of the bottom of the object actually being rounded.

Keep in mind the following caveats:

1) Its poorly supported anecdotal evidence (worked so far on a few prints, in my experience, but haven't tested it lots).

2) I'm not sure if it was the 2 layers of tape, or the acetone, or both.

3) There might be other factors in play -- the outside temperatures have dropped ten degrees lately, maybe it curls less in cooler weather.

[greengecko 8]

I am now also a fan of the two layers. My idea why this is working. Two layers make the bec more elastic, so if the head hits the printed plastic a some higher layer it is better able to absorb the impact and therefore keeps better sticking to te tape. This leads to a loner better attachment to the bed and therefore less warping. Because my first idea was that a softer two layer bed should be worse, but that's not te case. So far i have nevervused aceton. I guess it dissolve fat from fingerprints and therefore also leads to longer and stronger attachments to the blue tape.

Thanks for the hint.