You’re going to have to zoom In on the photo but while on orcas GitHub I noticed that there’s much stronger infills than rectilinear. I’ve only ever heard of a few infills being popular within 3d2a. Was wondering why the community doesn’t use the strongest ones listed instead?
Most functional parts are printed at 100% infill - at which point rectilinear is the optimal choice for strength and speed. Note that in Orca, as soon as you set sparse infill to 100%, it ignores your sparse infill pattern setting and uses the solid infill pattern setting instead (which has far fewer choices).
If you are actually using low to moderate percentage sparse infill, then gyroid is tough to beat (and often recommended for 2A prints). It gives good all-axis strength and consistent layer print times, but it is very slow. Gyroid also tends to be better for parts that need to tolerate flexing since it has a better ability to handle bending without developing internal fractures than most other patterns.
If you want fast print times, cubic is another popular choice. It has good all-axis strength, consistent layer times, and prints much faster than gyroid at the expense of self crossing on the same layer (which can cause problems with some designs and materials).
Don’t hesitate to try some of the others, but I think you’ll find any strength differences are quite marginal.
I’m thinking the secret is in the walls. Since printing a solid part is the goal, the walls provide the real structural integrity while the infill just acts as filler. With ‘rectal line ear’ it basically becomes one solid, continuous piece, making the whole thing way more durable.
