Small 90 degree overhangs without support

[egoaudio 0]

Hello everyone, 

 

I'm trying to figure out what settings might be most efficient for these types of overhangs. If you look at the images I've attached, you can see that the extruder starts to fill the 'bottom' of the circles in mid air. is there a setting that could possibly connect this with the shell instead of extruding in mid air to start the 'bottoms' (or tops depending on how you look at it) of these circular recesses? I've printed the part and since it starts like this the filament just ends up garbled in the hole. I'd like more precision of course. Support is one method, of course. This is only about 8 mm bridge which I feel like I should be able to get away with if it's connected to the shell.

 

Thoughts?

 

Thanks for reading and for your input, in advance. Happy Holidays y'all!

 

Erik O.

 

This picture is level 8 

Edited December 15, 2018 by egoaudio
add detail to photo

[smartavionics 287]

It would be helpful to see the complete layer 9 but I'm guess that it ends up with some skin partially covering the 3 big holes. Anyway, you have 2 options: (1) use support or (2) make the skin on layer 9 completely cover the holes and then drill them out when the part has completed. The skin only needs to be a single layer thick. I use this technique always when I have a small diameter hole directly above a larger diameter hole (i.e. when you have a nut trap or similar. Here's what I mean...

 

 

 

 

Hope this helps!

 

[egoaudio 0]

Thanks smartavionics! where do you add the skin? the model/cad program? or within cura?

 

I'm not trying to have a small hole within the larger hole by the way. just trying to have a recessed hole with a 'ceiling'. I'm going to put rubber feet on the bottom of this part so it doesn't slide around and a flat surface here would help with the rubber feet to adhere.

 

Support the best avenue then?

[smartavionics 287]

Ah, understood. In that case you don't need to add the extra skin if you use lines or zigzag for the skin pattern because then the skin should span the hole OK. Using the concentric pattern is a problem, it won't even work using the technique I show above.

 

The easiest way to add the extra skin is designing it into your model when you create it.

[egoaudio 0]

Thank you my good man! I suppose that's why I don't recall having these issues previously.... I must not have been using concentric for the bottom. 

 

I'll keep on printing! Happy holidays.