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Poor prints, help...

Posted: Mon Apr 06, 2015 2:28 pm
by krazyking01
I'll start with the problem. First several layers look great. They are uniform in thickness all the way around. Several hours later I go back and the layers have pulled up and are curling all the way around. I have blobs of plastic all the way around in random places. (I'll get pictures next chance I am able.) Odd thing is, this just started happening after several near perfect prints.

I've calibrated this thing 8 ways from Sunday and it is as near perfect as it is going to get. Center, X, Y, and Z all catch the paper within .02mm of 0. The nozzle is at 230 and the bed is at 95. I calibrated the machine with it at these temperatures as well. I'm printing ABS on blue masking tape coated with ABS slurry. I have it retracting 4mm whenever it has to move 2mm or more. My speeds are only sitting at 40mm/s. Can anybody help?

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 2:48 pm
by mvansomeren
Sounds to me like poor adhesion to the print bed. I had that problem intially and solved it using four layers of Elmer's Purple Glue stick. Put it on the glass bed directly (lose the blue tape) when it is at room temp. Lay down one layer, then a second layer in a crosshatch patern. the last two layers diagnally.

I think you'll find that this will end your curling problem which is contributing to your other issues, most likely.

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 3:33 pm
by krazyking01
I tried the purple elmers glue stick, and it was even worse. I applied it while the bed was hot and waited for it to turn clear. That's actually why I went to the tape/slurry.

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 3:40 pm
by Polygonhell
Blue masking tape does nothing for ABS adhesion, it's good for PLA though.

For ABS I use hairspray or UHU glue-sticks directly on glass, ABS slurry is also good.
Having said that a lot depends how big and what shape the print is, there is a limit to what you can print and stay have stay stuck with ABS.
230 is on the low side for ABS IMO.
Also not all plastic behaves the same, some is harder to print with than others (even of supposedly the same type).

Pictures will help people diagnose the issue. Seeing pictures of the first layer, then the subsequent issues would be ideal.

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 4:02 pm
by BenTheRighteous
95 is also pretty low for the bed. If you're doing glass with slurry/glue, I'd go with 110 at least, and 120 if you can get there.

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 4:36 pm
by mvansomeren
I use 235 / 95 with glue stick and I have trouble getting the prints off the bed...especially large prints. But, I also use a 1/16 inch aluminum defuser disk between the glass and the Onyx.

Here's a question, do you have any cool air or breeze hitting your printer? That could cause the ABS to warp.

Re: Poor prints, help...

Posted: Mon Apr 06, 2015 4:59 pm
by drunkenmugsy
I had this problem until I started rafting stuff. Solved it completely for me. I could probably do without the skirt when rafting but it gets the tip primed for the raft 100% of the time. I also use the purple elmers. At least 2 layers crosshatch hot or cold application doesnt seem to matter. Sometimes more layers. Works great for me.

Re: Poor prints, help...

Posted: Sat Apr 11, 2015 2:15 am
by radicaldev
I had that problem until I bumped up the speed. I tried a bunch of gluesticks. Elmers extreme hold sold at office depot works well when applied liberally, like .1mm layer or more. If you apply it to a hot bed, wait until it stops steaming before printing. The bubbly action going on seems to work against you.

@ 235/90, enabling wiping while retracting, retracting 4mm at 45mm/second and printing at around 80 to 100mm per second, I got away from curled edges and blobs, and started getting into good print territory. Less than 235, I was having layer adhesion issues with the black ABS I bought from Frys. Shaxon or something.

More than 90C bed temp takes more time than I care to invest while experimenting. Thankfully, the parts stick well at that temperature.