Hello Zortrax team,
I just saw an official zortrax promotion video, where a architectural modell of considerable dimensions including doors and window openings was printed without support!!!
I would be very interested to know how you did this,
what were the used printing parameters ( layer height, material, especially fan amount)?
Best
Andreas
Push…
if you pause the video just after the bridging occurs, you can see that there is still a little sag over what looks to be about a 1" span.
I'm guessing they are just springing at the slightly faster speed. I can't imagine they would be running full-fan on such a large model, but maybe.
I have found that when bridging such large gaps it helps to orient the part such that the bridging is occurring at 45 degrees to the machine. Because the "fill" would then be across the length of the bridge instead of the width. Perhaps they fixed this bridging issues (of the fill trying to traverse the width of the bridge instead of the length) in later firmware(?).
It would also be great if the software recognized a "bridge" or "cantilever" geometry and cranked the fan/speed up accordingly (I think Cura software does this, so I imagine the Zortrax team could eventually incorporate this feature as well... call it "smart bridge technology" or something).
Hello joshpit2003,
thanks for you answer, what would you say are the best settings for bridging ? I would guess 100% fan (as you said) and then which layer height ? 0.09 would be easier to cool but is very fragile, on the other hand 0.19 or 0.29 would be harder to cool...
if you pause the video just after the bridging occurs, you can see that there is still a little sag over what looks to be about a 1" span
yes i see it, especially at the inner door right hand side...
I have found that when bridging such large gaps it helps to orient the part such that the bridging is occurring at 45 degrees to the machine. Because the "fill" would then be across the length of the bridge instead of the width.
This sounds interesting, but I am not sure I understood you right, do you mean to rotate the object around the x or y axis (please see attached pic) ? This will probably work but is not bridging anymore ;-)
or do you mean the z axis? In this case I do not see the difference... the gap remains the same or not ?
It would also be great if the software recognized a "bridge" or "cantilever" geometry and cranked the fan/speed up accordingly (I think Cura software does this, so I imagine the Zortrax team could eventually incorporate this feature as well... call it "smart bridge technology" or something).
sounds like a great idea +1 !
best
Andreas
I meant rotate along the z-axis.
If you watch how the printer fills-in the body of parts you will notice that it deposits plastic at the same 45 degree angle (then cross-hatches). I get significantly better bridging when I am working WITH the direction of plastic deposit rather than against. When viewing the model from a top-down (looking at the X/Y plane) you should orient your model such that the surface to be bridged is at a 45 degree increment. Hope that makes sense.
to understand what I am talking about, simply create a flat object like a RECTANGLE with X thickness,
lay it down as you would normally. prepare to print and view the tool-path.
then go back to the model, rotate it 45 degrees along the z-axis, prepare to print and view the tool-path.
compare.
Interesting! I will sure try it out
Thanks!
What would you say is the best layer height / fan speed for bridging?
not sure if layer height matters much, but I would guess the thinner/lighter the layer the less sag you would have.
Fan speed to 100% is best for bridging, but would be a royal PITA if it started causing warp-issues/layer splitting on a large object.
not sure if layer height matters much, but I would guess the thinner/lighter the layer the less sag you would have.
Fan speed to 100% is best for bridging, but would be a royal PITA if it started causing warp-issues/layer splitting on a large object.
That’s why you should use my adjustable fan shroud! 
Using stock fans for large models at least on my experience overheat the lower fan and gets fried...
Max bridge for the model in the video is ~1.5cm, which can be easily done with whatever print settings.
Josh, I know what you mean, it seems to me that in 0.9 they've fixed it, layers/bridging are now related to the model itself, not z-axis rotation.
Warping is still an issue for me (not during the print, after cooling).
Think of a 50x50x2mm piece printed upwards - 1mm curvature at the bottom.
@Catalin C:
Are you saying that the bridging ability ist not influenced by fan or layer height?
I would be really surprised if that’s the fact…
Best
Andy
I think he's saying that at that minimal bridging distance it shouldn't really matter what your settings are.
And from my experience I'd agree.
Max bridge for the model in the video is ~1.5cm, which can be easily done with whatever print settings.
Josh, I know what you mean, it seems to me that in 0.9 they've fixed it, layers/bridging are now related to the model itself, not z-axis rotation.
Warping is still an issue for me (not during the print, after cooling).
Think of a 50x50x2mm piece printed upwards - 1mm curvature at the bottom.
hum, I haven't been having much of a warping issue. There's lots of tips about preventing that sorts stuff, and I think I even wrote up a post with pics about enclosing the printer. Now I've got laser-cut side panels. Wrote a post about that too.
I was saying that for a model with thin walls, a ~1cm bridge is not an issue, comes out fine even on default settings.
Not the best choice of words. I haven't had warping as in print lifting and fail for months, even with full bed.
I meant finished model shrinking, but that is geometry and ABS related, not much you can do about it.
What would you say is the best layer height / fan speed for bridging?
I'm still pretty green but just printed this Math Spinner from Thingiverse:
http://www.thingiverse.com/thing:452651
The bridging over the horizontal top segments in the numbers sagged at 0.19 mm layer height but were gone at 0.14 mm height. I may have also increased the fan speed from 20 to 60%, though. Gotta start taking better notes.
Mike