03-03-2022, 07:07 PM
(03-03-2022, 01:28 PM)Highpower Wrote:(03-02-2022, 05:45 PM)arvidj Wrote: Certainly not a tutorial on bridging but it can give you an idea on what is possible ... and especially not possible ... Bridging ... until you get your printer tuned up.
It just happened to be the first page listed by google when I searched for "3d printing bridging".
I started watching several videos and reading some web sites and (I think) I learned a few more things. Bridging and overhangs are not one in the same. Bridging involves anchoring between two points whereas overhangs are only supported from one side. It's like two people holding up a yardstick between them using only their fingertips vs. one person holding a yardstick horizontally from one end of the stick only with their fingertips. In all the examples of bridging I saw both ends were supported all the way down to the table. I did not see any examples of bridging that started half-way up the part and off of the table. I didn't spend all night looking for such a case though.
From what I saw the trick is to get the material to solidify the instant it comes out of the hot nozzle which requires a lot of air flow to cool the extrusion immediately upon exit from the nozzle. Between having to get the melt temperature just right, getting the cooling ability just right and having to fight gravity the entire time makes me glad I didn't go down the 3D path after all. Not enough time left on my calendar to try to learn it all.
Kudo's to the ones that can pull it off though.
Agreed that, in the end, bridging and overhang are two different things. But if you think about it, until the bridge is created it is a hell-of-a overhang.
The extruder does not put out a 'ruler' that is immediately supported at both ends but a 'stream of hot plastic' that has to start at one end or the other and then, eventually, end up at the other end. As such, until it gets to the other end, it is, at least in my mind, an overhang.