Would like to be able to print a different directions

In the piece below water is expected to flow down the slope and off. But due to the lines from printing that does not work well. Would like to be able to say which way things should be printed. Understand that is an issue due to height interference issues. Makes me think a nozzle setup came from the side or some other changes to get greater access to shape would be a great evolution of the printer. Or a six-axis print head…

Those look like they’re lines designed into the model?

If not, maybe this is just a limitation of using luban.

Both Cura and PrusaSlicer (or SuperSlicer) have an option to do a method called “ironing”, where it goes over the flat top sides of the object and spits out just a tiny bit of filament with the nozzle at temperature, leading to an extremely flat surface.

Also, this could be an issue with the orientation that you printed the object in. If you printed with the ribs down (i.e. upside down compared to the picture you’ve shown), then it’s likely that the printer had to do “bridging” across the ribs (e.g. if you were printing an “n” shape, the top of the letter would have to be bridged). Bridges will usually end up with a little bit of sag, especially if you haven’t gotten crazy with fine tuning your print temps/speed (things which luban will try to hide away from you). If that is the problem, you could try flipping the object over before printing (I think even luban offers the ability to modify the rotation of an object). In my letter example, that’d mean printing a “u” instead of trying to print an “n”. Since the printer no longer has to bridge a gap at the top, it can print tbe bottom nice and flat, and then build tbe walls on top.

I personally want to try out a printer I saw a few days ago. The entire printhead is a gyroball that can print in any direction, even straight up. Bed is double sided. Still in prototype testing stages I think. And I imagine the cost for that will be quite high at first.

Can you upload or link to the model?

I assume you’re complaining about the lines that run parallel to the long edge of the picture. From what I can see, the object has a slope to it, because the base is thin at the bottom of the picture, and thicker at the top of the picture. The lines that run parallel to the short edge of the picture look to be constant absolute height, but get relatively shorter at the top of the picture because the base rises up to meet them.

If that’s the case, you’re going to have some lines just caused by the height stepping up. The best way to make those steps smaller is to lower the layer height. That does make the print slower (more passes), but each step is less. I’ve printed with a layer height of 0.05mm, and it makes very fine steps. Depending on how thick the base is, you might be able to speed things up a bit by making the initial layer thicker, then the rest of the layers are thin.

Another option would be to rotate the part around the X axis, so that what’s currently the vertical wall at the top of the picture is flat on the buildplate, and the bit that’s flat on the table becomes a vertical wall (you’ll probably want to enable a brim or raft if you do). Without being able to test it, I believe the stair steps in that orientation would be finer. You will probably need supports everywhere to keep the the C cutout walls crisp. Either way, I’d make sure I used the layers slider after generating GCode to examine the tool head path before starting the print. In either orientation, running that slider up and down should give you an idea how coarse the stepping will be.

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You’ve got a slicer problem, and not one specific to Luban. In order to get what you want, smooth channels at an angle, you need to lay down filament in parallel with the ribs. The problem is that in the orientation of the model as it is, filament would need to be laid down on a non-level surface, with changing Z-height as the filament goes down. The machine is physically capable of this, but slicers are not. There are physical reasons for this choice, as the slicer would have to worry about molten filament slumping, etc.; don’t expect it.

What you can do is to change the orientation of the model. Tilt it at an angle so that the “drain surface” is flat. Add supports under the base (currently flat, will be on a slope) in order to enable this. Slice as normal, then check the deposit direction. If the filament isn’t being laid down parallel to the ribs, rotate the model in the X-Y plane until it is.


The STL:
Bottle Drain_v1.stl (528.4 KB)

Be a while till I try out the options suggested here. Uses a lot of filament…

When I’m prototyping big parts, I like to scale them down for iterative testing.

If you scale that down to 10%, the C walls and ribs are too small to print, leaving just the base with it’s obvious stair steps.

Riffing on @eh9 's suggestion, rotating the model -6º around the X axis and enabling supports makes the top of the base flat, and the bottom of the model has the stair steps. And it only takes 10min and 1g of filament to print on my v1.

If I keep the rotation and bump the size up to 25%, now the ribs, back, and C cutout walls are big enough to render. That’s a 2hour print, using 18g of filament in High Quality mode. That’s an acceptable prototype test for me. If I run through the layers sliders, I see there are still a few steps from layers 66 to 73. -5º rotation on X gives me a smooth layer 65. If you happen to know the exact angle of that slope, that’d be better than my guestimates based on the layer previews.

Because it’s being tipped back slightly, the bottom of the print, the back wall, and the top of the ribs are going to have that stepped texture instead of the top of the base.

I only have a v1, so I can’t print the 100% scale. I’m also not terribly happy with the current state of layer previews in Luban. Using Cura, I can get a much better idea of how the print head is going to deposit filament on any given layer. But Cura makes me use the mouse to rotate rather than typing in a number, so it’s a lot fiddlier to get right. It’s going to print the top skin of the base on a 45º bias, so I’d recommend rotating the piece +45º or -45º, which ever way makes the top skin print parallel with the ribs instead of perpendicular. For my 40% scale, -45º around the Z axis made the lines on the top of the surface parallel to the ribs. Although that complicated things in that now I needed a different amount of rotation on both the X and Y axis, so it might not be worth the extra time. Here’s a zoom of the lower left hand corner, at layer 72 (with a few layers of the ribs printed).
Screen Shot 2021-04-14 at 11.29.27 AM
That should make the water drain pretty smoothly.

I think using the layer slider preview, you’ll be able to dial in the exact angle and print direction to give the best drainage. I’d definitely do a couple small scale tests to make sure you understand how to read the preview before you re-attempt such a big print.