How do I eliminate warping on PLA printer?

Hi all...

Things were going well, with nearly a 100% success rate on printing with the new PLA ROBO 3D. Then, things started warping on me. I even tried a small (1.5 inch) hollow cube, which started warping after about 5 or so layers. The trusty TARDIS I printed early on won't make it to the 10th layer without the edges curling up about 1/16th inch. Of course, once that happens, things get real ugly.

The specs are all the same, and the temp appears to be fine.

Any tips would be greatly appreciated. My next project is a chess set, so I want to make sure all is well before I take the project on.

Thanks

 

I am having similar problems to Iggy. Here's a pic of the warping I'm getting with gold PLA. I assure you the spools are not mislabeled. I get this with blue, black, and white, too. I began with using a non-heated bed according to instructions, but for certain models I got such severe warping that it knocked the model free, and I'm using Krylon spray adhesive on blue painters tape, very sticky. So, I thought I ought to try heating the bed a little (65 C) which seemed to help a little, but still there's warping. I haven't had much time to test it but I really want to make a Tardis for my daughter and it ain't workin'. I included a pic of the warping. This model was built with an extruder temp of 190 for the first layer and 180 for others. Maybe it's the fan, but I'm not clear on how to override it. There is a button in Repetier but it turns on again soon after I turn it off.

 

The fan keeps the extruders hotend cool, so turning that off is tempting fate for running too much heat into the extruder. I'd try turning the bed temp up a bit more perhaps. I've been using it for my PLA prints as well, and was using it at 65c for first layer, and 60c for subsequent, and not getting any warp. Not all PLA is equal, and I got mine not from the Robo guys but a supplier direct from China. I bought eight spools of filament from http://www.repraper.com and with shipping ($80, ack!) it still only worked out to $25 per 1kg spool. So far I've only printed with the one (tardis!) blue PLA spool, but it's worked really well for me once I (finally) got the adhesion problems we all seem to hit at first finally resolved.

 

Matt, thanks. I am still learning. In fact a co-worker was thinking it might be related to the spray adhesive I was using. Looking carefully at the pic that tesseract posted above, it appears the first layer is kind of flattened which I assume helps with making good contact, so I tried fine-tuning my z-elevation and turned off the bed heater and it seems to have solved the problem, at least with black PLA. I will try gold next. I am still using blue painter's tape, but no spray adhesive and no bed heater, and I wipe the painter's tape with alcohol right before printing.

 

Yes, I did try hairspray on the glass and on the painter's tape with no success but that was before I did my fine-tuning so I may revisit that again. I recall someone saying Aquanet was the hairspray to use but I couldn't find it in Vons so I got something else. Maybe it's gotta be Aquanet? The models I'm having particular difficulty with are these platonic wireframes (http://www.thingiverse.com/thing:38302) . I am trying out the structural materials option in Repetier and it seems to be working but it doubles the time to print. I probably need to refine those settings, too.

 

Aquanet Extra Super Hold Walgreens. Using 50C heat on PLA energizes the Extra Super Hold even more. Sticks like glue and "gives your hair great body and volume "

Measure the thickness of the print ring created on the first layer. I think the Slic3r Advance setting for first layer extrusion width 200% dumps out extra material for the first layer. Good measured thickness is 0.3-0.45mm (maybe). You can adjust your first layer height in Slic3r in Printer Settings>>Layers and perimiters>>First layer height to tweak the thickness. There should be a good deal of squishing of filament on the first layer to get good attach. Also remember to preheat your extruder when doing Z calibration. Extruder gets longer by 0.2mm when hot.

Also set bridging flow to 0.9 to pull across big gaps.

 

I was using just 130% for my first layer for extra material to great success with just glass, no hairspray. Blue tape didn't work for me for **** with PLA. Never stuck for damn! Soon as I lost the tape, went to just glass, heated to 65c for first layer, cleaned well with rubbing alchohol, and made sure my Z height was correct and bed was level, I started having success. I dropped the bed temp to 60c for subsequent layers.

If you can easily remove your first layer then don't expect it to stick for the rest of the print. You want that first layer to be stuck down good and wide and flat!

 

Matt - Everybody has a different calibrated piece of paper for setting the Z height and people are using different first layer Z heights in slic3r. What is really important is the resulting thickness of the first layer. I would be very curious in having you measure the thickness of the priming ring that gets printed around the part before the part printing actually starts. I was also headed down the road of bare glass 65C or so for first layer on PLA. That seemed to work ok if the PLA is really getting squished on the first layer to like 0.2mm measured. Glass had to be really clean. Then I stared using hairspray at 50C which gave me many times more stick and it was much less sensitive to bed height and absolute cleaning. In fact, I don't have to clean or even add more hairspray on every new print. I use a piece of paper to as a shield to keep the spray localized on the bed.

 

I just don't have any hairspray here at the ranch... Keep meaning to get some next time I'm in town, but keep forgetting when I'm there. I'd agree too that everyone has different paper and different settings. Just trying to share what I do and what works for me. {shrug}

 

I can try and measure my first layer height on my next print... tho typically I end up removing that rim ring as it's printing as I'm heating the hotend while I'm kicking off Slic3r and depending on how long slicing takes, it might overcook the PLA a little bit and that ring goes down a bit off. I've got my dial test indicator here tho, so I should be able to take that measurement and report back.

 

Having trouble using hairspray with ABS on larger parts with bed heating. Edges are warping up. Will try a bigger PLA run, but will head to kapton an ABS slurry for ABS next.