How far can a 3d printer extrude (laterally) “in the air” without supports? What would be the best setting to maximise 3d print span?

I think it depends on what nozzle size you are using,the material, the layer height, the angle of the overhang, the cooling and speed.

it’s something you could test yourself with the setting you want to use, I think it is safe to say you need around 50% of the nozzle diameter, still attached to the previous layer.

As Xeno said, there’s a lot of factors involved, so there’s no simple answer. I think however we can safely say you’re going to want the temperature of the filament as cool as it’ll go and still print well (so it’s as stiff as it can be asap). Depending upon how you’re printing/your experience, you may be able to edit the GCode to adjust this temperature only for the sections where needed.

I try to avoid overhangs as much as possible, often a little thought about the model itself will show an alternative possible orientation on the mat, or a way to print in more than one section that allows seamless/good looking assembly.

Hi there!

As Xeno and cobnut said, there’s no easy answer to this question. Some filaments, like CooperFill can achieve dramatic overhangs because of the material properties whereas ABS is much more finicky about it. In general, an overhang of 45° is considered the point where support will be needed, but printers with active cooling (extruder fans) can do upwards of 55°. You can try going this high as a starting point, then dropping it down if you get too much curling/noodling/drooping.

If you have a part you don’t want to use support for, your best options are trying to reorient the part or printing with dissolving support (if you have dual extrusion capabilities). Orienting models for printing is as much of an art as a science, so this does take time to learn. If you have the ability to print dual material, soluble supports are fantastic. You just print the part in whatever material you want, and print the support in a material that can be dissolved away after the print is done (water, d-limonene, etc.). PVA is a bit tricky at first (use this to support PLA), but HIPS (used to support ABS) is a great material and I can not recommend it enough.