Design tips

When using homemade 3D printer there are some restriction during the printing process, if your model got overhangs parts, there are few options:

1. We will print it with surport material, you will need to remove the unwanted surport material by cut or file it off.

2. Or you can break your model into parts, stick them together after printed.

Design for No-Support: 45 Degree Rule

The homemade 3D printer don’t have support plastics like the expensive 3D printing machines from Dimension, and while Skeinforge does have a “support gridding” option, at the moment you’re much better off altering your model so you don’t need it. Today we’ll discuss making shapes more print-friendly with a minimum of impact to the shape of the final object. The basic design rule is: no overhangs greater than 45 degrees. If you always obey this, odds are you will never have a problem with dangling plastic noodles.

This, however, is a rule that can be bent, and occasionally even broken, if you think ahead and in terms of 3D printing technology. One key: overhang is size dependent. A 2mm circular hole will print just fine with no tear dropping, but a 2 centimeter hole will start to get droopy loops:

Droop is also a function of how long the overhang goes on for. If an edge of a layer is resting almost on thin air, but the noodle marking this perimeter only dodges briefly out over the abyss, it’ll likely hold firm, whereas a long trek can cause the whole thing to sag in the finished print. You can even get away with short horizontal jogs out into nothingness if they’re brief, especially if they have someplace to go. Note the test part with a square(!) horizontal cavity here:

The truth is that both holes will probably be usable, although you’ll have to file off a bunch of ugly hanging plastic on the cavity to the left. Horizontal overhangs shorter than a centimeter will often hold up just fine!