Print circle arcs without supports

I'm still putting aside money for buying my first 3D printer and I'm designing all the things I have to print.

As I have a lot of things to print I would like to print as much of them as possible in a single print.

I have some arcs of circle (between 90° and 320° and 10/30 cm of diameter) and I'm going to slice them so I'll be able to print many of them, vertically, in a single print. I read in the internet that I cannot print over 45°... but starting from where?

The image below shows how I would like to print my (orange) things

I suppose I can print my things without supports because from Y-start to Y-end they are <= 45° (as the green line shows) is that right?

The red line, instead, shows a case where the angle, starting from a (Y: 50%) point, is higher than 45°.

So the question is: Can I print my things in such way?

• The overhang is from 1 layer to the next. 45 degrees relates approximately to a 50% overlap from one extrusion to the one above. Feb 7 '17 at 15:27
• Why don't you want to print them horizontally? It would seem a lot easier. BTW, your axis system there is left-handed. You should fix that. Feb 7 '17 at 17:56
• @CarlWitthoft I want to print them vertically because if I print orizontally I can print 5-6 at same time, if I print vertically I can print 60-70 (a small part) of them with one print. Moreover the shape constraints me to use supports i.stack.imgur.com/9kuwT.png Feb 8 '17 at 11:30

There are a lot of variables here...

If you did at ..

1. higher resolution.
2. Calibrate your machine extremely well. Trial and error. Minimum temps and speed.
3. If you use a fan.

IE bad calibration. Good calibration at a slower speed and lower temp.

What is going to happen is you will get a lot of junk, lines, loops, stringers that you can later remove with clippers. See the first photo for an extreme case. It still printed.

Also if you use the right material as well. Some material, will do bridging better, IE ABS has a longer molecular chain than PLA so it tends to do overhangs / bridges better.

Images from ultimaker

This depends on your material, your nozzle diameter, and your layer height. In general, shorter layer thicknesses with wider path widths will give better overhangs. And note that the last bit of each of the larger arcs are nearly horizontal, and I do not expect them to work well without support material.

See the excellent answers at How can I improve the overhang angles my printer can successfully print?

• Awesome and I think it might even work! Feb 10 '17 at 18:57