I'm printing an L-shaped bracket that will hold a light shelf, not a decorative model. The first version looks lovely but cracked along a layer line when I tested it by hand. I'm using PETG with four perimeters and moderate infill. I can rotate it so the main bending force acts more along the printed strands, though that requires supports. For a functional part, how do you prioritize orientation, wall count and fillets before worrying about infill percentage?
Printing a functional bracket where strength matters more than appearance
- 3d-printing
- printing
- functional
- bracket
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5 replies
For a shelf bracket, I’d care more about orientation and wall thickness than infill. If the load is trying to split layers, no amount of che...
For a shelf bracket, I’d care more about orientation and wall thickness than infill. If the load is trying to split layers, no amount of cheerful infill percentage really saves you.
Exactly. More perimeters and a fillet at the inside corner usually matter more than going from, say, 25 to 40 percent infill.
I’d rotate it if you can. Supports are annoying, but the print is usually stronger when the bending load isn’t prying layer lines apart.
And the fillet is doing real work there, not just looking nice. Sharp inside corners are where little cracks start.
One thing I’d check is whether the bracket is being loaded in bending or as a peel off the wall. That changes which orientation is actually...