Print warping?

[sizemore]

I can run small prints like vehicles and small items without issue. When I goto print larger items, I am having an issue with warp on the long axis of the print. I typically float the print with supports, and now I'm experimenting with angles (ie. ArcTan(layerheight/pixel size). I'm trying to determine if its FEP suction causing the warp or exposure issue with shrinkage. I think its a FEP suction issue, since the high numbered layers were perfect and straight. When the failed print was printed on an angle, it was much better but still a slight warp. Testing it again at a high angle (ArcTan says 65* is my golden angle). Any guidance is appreciated!

The S.

[Chris333]

Depends what you are printing. If I print something tall and thin I will print it standing up and leave it attached to the raft so it cures even on both sides.

[sizemore]

Yeah I've found the closer I get to vertical (over 60*) the better everything is, as evidenced with the latest print. Figures it's your boxcab that I am printing too.

The first was a Hail Mary based on our past chat. The second (without supports) was to see what printing on an angle would do, the latter (in the back) was the latest test, tinkering with supports. Its good, but may give it another go later in the week at the "golden angle".



The S.

[GGNInNScale]

I found that large-50mm or more straight walls benefit by having internal braces- easy to add.  I have not seen the end warp effects unless I do not have enough peripheral supports.  You might try adding some extra supports to the perimeter beyond the wall edges.  Good luck!

[Chris333]

Don't think that is warping, it is under supporting. if you look here I just added a file called "supported". It is the exact file I used to print mine. Just open and slice. https://www.printables.com/model/528899-n-scale-boxcab

[ggbutcher]

I'm finding that larger "unattached" walls, that is, walls that grow in a sheet without support or some other dimensional attachment (e.g., another wall at a right angle) will warp.  I modeled my locomotive tender "per-prototype", with the water wings surrounding the coal storage space, so long thin walls:



On the left is the cistern turned upside down and frame; that warping manifest itself after curing, as the model sat under the fluorescent light of my workshop.  The right-hand cistern has spacers inserted to force dimensional stability; I print the cistern at a 45-degree angle, so those spacers are designed to not need supports at that angle. 

I'm also working on a station model, I'm printing the four walls as one unit, right on the build plate. It's N scale, about 3" x 2" footprint, I over-thickened the walls to about 0.05", not prototype but I'm curious to see how noticeable that is through the windows.