How do I print a honeycomb structure that I have designed using the technique that infill uses?
I'm trying to print what is essentially a honeycomb infill pattern which I want to be 3.2mm A/F on the hex with a ~0.8mm wall thickness.
When I import the STL into Prusa slicer, it's going to take 10+ hours.
But If I import a solid block the same size and choose a honeycomb infill then it only takes 4 hours.
So presumably Prusa Slicer uses some algorithm to print honeycomb infill in the most efficient way which it doesn't do If you make the mesh yourself?
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
I guess that big difference in printing time comes from the fact that Prusa Slicer (and pretty much any other slicer) have different presets for infill speed and perimeter speed. I would guess that Prusa Slicer interprets your modeled honeycomb as only perimeters since the 0.8mm wall is just two perimeters. It will the slow down your printing speed to the lower perimeter speed.
Try increasing all your perimeter speeds to what is set for infill and see what time it comes up with then.
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
thats that timo-m is trying to explain
- when you slice a solid block the slicer removes a layer around the object the width of the perimeters and considers the rest of the volume as "infill" and prints all the infill at infill speed
- when you slice a hollow object with designed in fill the slicer sees everything as perimeter and nothing as "infill" so prints it all at perimeter speed
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
one thing you might be able to do is add a modifier block to the object over the interior area and modify the print speed in the area the block covers
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
OK, I've tried changing the external perimeter speed from 25 to 80 and it makes very little difference.
I think the main problem is the method it uses to print. If you look at the screenshots below you can see that on my design it prints hundreds of tiny hexagons side by side. Whereas on the infill image you can see that it prints long, jagged lines which stack up to become the hex pattern. (less time lifting the nozzle up)
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
If it is just a honeycomb structure you could also switch to a bigger nozzle (e.g. 0.8mm) and print the solid block model with zero perimeters. That may result in something close to the same Gcode?
How many copies of that part are you going to print? I'm just wondering if it is worth trying to optimize printing time or rather just let it run for half a day and be done with...
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
How many shells does your part have? If you can merge them into a single shell the slicer may treat them differently, with only one single perimeter.
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
If I print the solid block model then I can't specify that I want the hex size to be specifically 3.2mm. Or did you mean the other model?
I potentially will want to print hundreds of these in various sizes
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
Hi James,
the Prusa automatic infill is, as you say, different to your original model,
have you noticed that alternate layers create either a single .perimeter or a double perimeter.
which interleave to integrate all of the hexagons into a solid mass, creating a more robust structure.
where as your individual hexagon model relies totally on inter filament bonding for strength resulting in a relatively less robust structure.
the prusa automatic infill will run continuously for a greater (wiggly)distance with few stop start / retraction, z lift actions,
where as your model will print with lots of stop starts (decelerations and accelerations) and with loads of retraction/detraction, and z lifts. also adding to the time difference
try slicing again, but make retraction 0 mm... the print time for your individual hexagon print should reduce.
I don't think you can do a lot about the acceleration/deceleration times
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
Yes, this is exactly what I'm talking about 🙂
What I want is the strength, plus the wiggly, interleaving methodology but to be able to specify the hexagon sizes in mm rather than as an infill percentage. Is this possible?
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
Hi James,
I dont believe there is a way to specify the infill dimensions precisely
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
No, but couldn't you just run at different % infill and extrapolate the percentage needed to hit your specified hexagon size?
RE: How do I print a honeycomb structure that I have designed using the technique that infill uses?
A good mathematician can predetermine the frequency of the hex infill by setting infill to 50%, measuring the resulting spacings, and then adjust to obtain the desired actual dimension.
0% is NO infill, 100% is everything. 50% fills 1/2 the volume with plastic, and the infill width is used for that determination. But there is some infernal constant that is used that you have to discover by experimentation. I did this a while back to get 1/4" and 3/8" hex patterns... but tossed the Excel file. I was needing center to center control, but the same theory applied to openings.