Best practices for overhung parts

Guys, I clearly am not using the best settings to achieve good overhangs, even when using supports. The underside of some flanges that were printed with supports underneath look pretty sloppy, even though the are only 8mm wide, and the same can be said for counterbores on the bottom faces.

The settings are basically stock for the proto-pasta ABS, with just initial layer height and normal layer height changed. What settings should I be looking at to give me the best chances of these overhangs coming out OK?

Cheers

Les

Pictures would help… but I can probably guess what it looks like.

Its hard to get a solid bottom on any large flat overhang (5mm). The hotend is printing in mid-air and expecting the cooling of the filament to lock it in place. Since there is no surface to print on, the extrusion doesn’t have an opportunity to widen into an oval… filling gaps.

Best results I’ve had are with S3D and using dense support layers or keeping the supports to 3-5mm gaps. The dense suppot feature, essentially creates a “platform” for the print. It can also help conserve filament… for example using a 15% support density, then enabling dense support layers (3 layers) @ 70%.

Keeping the support gaps to 3-5mm stays within the range which the hotend can print without significant sag of the extruded filament. Make sure you’ve got cooling at 100% for overhangs… this solidifies the extrusion as it leaves the nozzle opening.


Hope that helps.

Thanks, will definitely gives those a go!

Cheers

Les