Unanswered Edges lifting/warping

I apologize if this has been addressed elsewhere. I searched, but couldn't find a thread with an answer.

Yesterday, I tried to print out one half of a spool holder for my R1. After a couple of tweaks, the first layer went down perfectly, smooth, solid, no gaps or ridges, couldn't ask for a better result. I was in my office and kept an eye on the print for the first several layers, all of which looked great. I left the job to finish on it's own and came back a couple hours later to see the end result. What I saw was a real bummer. The edges of my print had warped in several places and lifted off of the bed (see photo). Aside from this, the rest of the print looked great. I'm not sure what the likely cause of this is, but would love input from anyone who has resolved similar issues. Thanks!

DETAILS:

Filament: 1.75mm White PLA
Extruder: 191°C
Bed Temp: 70°C
Fan turned off for first 2 layers

 

Hi, I had this same issue. Use extra hairpray on the bed at that corner, and it will lie flat. Usually the corners furthest from the center of the bed require a little more hairspray in my experience.

 

I tried both of the above suggestions (used more hairspray and raised the extruder temp a couple degrees), but got the same result. Any other thoughts?

 

I think it's a cooling issue. I lowered the in-fill a bit so that there will be less hot plastic retracting to pull up on the edges and I'm going to try printing it with a good sized brim to see if that helps. Here goes nothing...

 

I ran a third print with much better results. For those who want the technical details, I am using MatterControl with MatterSlice as the slice engine. Also, I did not alter the temperature settings from my second attempt. Relevant print settings follow:

First layer speed: 30%
Infill: 20%
Extruder Temperature: 193C
Print Bed Temperature: 70C
First Layer Extrusion Width: 120%
Disable Fan for First 2 Layers​

I also printed the part with a brim by adjusting the skirt settings as follows:

Loops: 20
Distance from Object: Touching - 0mm​

The result was a thin brim along the edge of the object extending out by just shy of 10mm. There was still a slight amount or cooling warp on the corners in question, but not nearly as pronounced as in the first two attempts -- and for this particular job, I am able to use part as it printed this time around without issue.

I am going to attempt to print the other half of the spool holder today and will be adjusting a couple of things in hopes of further improving the results. First, I plan to slow the fan speed to 75-80%, rather than running it at full speed, in an attempt to produce a more gradual cooling process that I hope will reduce the internal pulling that is lifting my corners. I figure the part is big enough that it has a lot of time to cool between layers already and likely does not need as much fan assistance to prepare for subsequent layers. Additionally, I am going to rotate the model 90-degrees so that its length runs along the x-axis, rather than the y-axis. My hope is that this may also help make my temp-delta more consistent by keeping the model a bit less exposed to the cooler air outside of the printer and reducing the y-axis movement needed for printing. Using an infrared thermometer, I also found that the bed temperature seems to be significantly more consistent along the length of the x-axis, with only a 2-3 degree drop at the extremities, compared to the temperature lost at the far points of the y-axis, which were as high as 7-8 degrees. Here's to hoping for a good result!

 

Oops! I forgot to drop it back down, which I meant to do. At any rate, I also forgot to rotate the print orientation as I mentioned in my last update, so I cancelled it and am about to restart it now. I'll try the bed at 50C and see how it goes. Thanks!