PLA curling up issue

[helifrek]

Hello all,
My M2 is only a few days old and has been printing up a storm! just about everything I have printed so far has came out perfectly with one exception and not on any particular print.

When printing an overhang with no support at a sharp corner I notice the PLA tends to curl up. On a larger print, this isn't much of an issue as the next few layers eventually push it down into place. But on small prints with finer details it can pretty much ruin the print. I have noticed higher infill makes the issue worse.
What are some ways I can help to prevent this in the future? I did some google searching but everything I found dealt with the print curling off of the bed which is not my issue.
I did lower my extruder temp a little and decreased the infill which helped. I also printed to objects to allow time for the layers to cool but it still happened, not as bad though.

black makergear pla
S3D stock M2 setting on medium
70C bed temp
215C down to 205C extruder temp
%50 infill ( I tried as low as 20 and up to 100 as well)
.20 layer height

Thanks in advanced guys!
Brandon

[insta]

Try with the bed at 60C, and the bed coated in a dilute layer of elmers glue, or rubbed down with a single pass of an elmers glue stick.

[benavery]

You can minimize the curling by cooling the material as much as possible after it has been extruded : Make sure the bed fan is running. If the overhang is only on one side of the model (rather than all around), then orient the model so the overhang points forward to get maximum cooling from the bed fan.

[jsc]

I think insta's suggestion addresses a problem you do not (yet) have, but keep it in mind for the future when your glass isn't pristine.

Ben has it right. PLA is a great printing material in most respects, but it is prone to overhang curling. I did some experiments when I was having this issue, and found the more cooling the better. Make sure your fan is running, and if it's still not enough, try augmenting it with a desk fan.

[helifrek]

Thanks for the advice guys.
I do not have the problem with it curling off the bed (yet!) but will keep the elmers glue in mind. I have been using Aquanet since I had the Flashforge and I swear by it! that stuff holds great. Most of my prints actually stick too well! I wash the glass with hot water and soad every 10 or so prints then I wipe it down with 70% Isopropyl Alcohol to get any leftover oils off and then I do a coat of hairspray.

Do you guys think a fan duct would help with the issue? I will keep reorienting the model in mind the time it happens! I am printing a bunch of tricopter parts right now and I can only see it in one corner of one of the parts. So not bad at all.

[jsc]

A fan duct might help, but I haven't seen anybody doing anything on that front. There are a few Thingiverse M2 ducts, but they are for an earlier version of the extruder I believe.

[helifrek]

Where are all the smart engineer's at who design the complex stuff? I am pretty good with electronics cases but that's about it!

Off subject but.... I was thinking it would be cool to make something where you would be able to level the 4 corners of the bed versus the 3 level screws. Seems like it would be so much easier to level the bed that way.

[ednisley]

level the 4 corners of the bed versus the 3 level screws

Remember that three points define a plane surface: a fourth point can only get you in trouble.

Imagine a platform with screws on three corners: the fourth (free) corner will move as you adjust the diagonally opposite screw. If the free corner had a screw holding it in place, you'd bend the platform if you didn't tweak the two opposite screws by the same amount in opposite directions.

Putting the three points further out toward the corners would reduce the length of platform beyond the screws and allow finer adjustments, but that would enlarge the support structure holding the screws and increase its weight to maintain the same rigidity.

Tradeoffs! Tradeoffs everywhere!

[helifrek]

Makes sense now. My old flashforge had 4 bed leveling screws and it could sometimes be a pain to get perfect but it made more sense to me. I guess I just have to get used to it
I have tried all the different bed leveling techniques in the Forum and each one seems to have it's ups and downs (pun intended )
I just need to order myself a dial indicator and print out the adaptor so I can get it perfect!

[pyronaught]

Makes sense now. My old flashforge had 4 bed leveling screws and it could sometimes be a pain to get perfect but it made more sense to me. I guess I just have to get used to it
I have tried all the different bed leveling techniques in the Forum and each one seems to have it's ups and downs (pun intended )
I just need to order myself a dial indicator and print out the adaptor so I can get it perfect!

I've been using one of these: http://www.amazon.com/gp/product/B0043F ... UTF8&psc=1

You really don't need to spend a bunch of money on the more expensive ones, the one above does the job just fine. It is certainly a lot easier than placing a sheet of something under the nozzle head every time you need to take a measurement.