I’m working on a brush for printing so have included in my model a 60 by 70 patch of 0.3mm cylinders that are 25mm long. I have bookended these cylinders
with cubes but predictably the software choked when I tried to prepare a render for print.
Does anyone have any experience with what the upper limits may be or what sort of settings I may have to employ to get this to work?
I’m having trouble understanding your request. Could you upload a screenshot of your model?
If you’re asking about the theoretical resolution of the printer, it’s highly dependent on the filament, so empirical testing is the best way to verify it.
Regarding slicer capabilities, there’s no published limit on the maximum number of vertices a 3D STL mesh can have. However, my personal experience has been that I have yet to run into any limitations including those with hundreds of thousands of vertices, like topographical maps from the USGS. So I highly doubt a brush with fewer than a millions bristles would be much more of a challenge. 
Have you tried running the model through the slicer to see how it handles it?
Hi
This is an interesting question.
In slicing large files, my limits were always regarding hardware and in pretty good machines. So, I conclude that this depends on the hardware and time.
Generally, you can use the model, which can be efficiently done if you design it.
To provide a detailed answer, further data about the mode is needed.
I’m complete newbie when it comes to the printing, I’m alright with the modelling. When I was prepping it to send to print, the model transferred into the Bambu software unchanged but when I loaded it into the slicer it dropped all of the bristles.
Just a note in case its not obvious, the plan is the cut down the middle of the printed object with a knife to create two brushes 
To be clear, systems specs have very little to do with the slicer program. The slicer program will run cheerfully on 15 year old hardware, it does not use graphics acceleration nor will employing a gen14 Intel processor make much of a difference. If the machine can run Windows 10 effectively, in can run any model in a slicer. Sure maybe it might take 10 seconds to run on a gen 1 i3 versus 8 seconds on a Gen 10 i7 but who cares?
Now on the subject of your brush. What is preventing you from simply printing it?
The screenshot you provided isn’t from Bambu Slicer (BS), which software package are you using that you say “it choked”?
I agree that you can slice in an old machine without an issue.
My empirical knowledge shows that if the file size (not necessarily print size) is large, my machine hardware (processor and memory) is pushed to the limit when trying to slice, and this happens with many software (Cura, Prusa, Bambu Studio, or more specific ones such as Solidworks, fusion).
so, here is what I get when I slice -
As the preview render did not display the bristles spanning between I’ve guessed that all that will print is the blocks;
… the software that I am using to model is fusion 360 which has had no real problems so far (but not really the issue) ; I exported to Bambu as a .3mf.
At the moment I’m reducing the amount of bristles until I see a good render but being able to find a way to calculate how and why would be interesting and useful.
you need to go into the settings, change stuff like resolution, and also line widths, I expect. I? would try a test print, maybe only 5 mm high, see if the bridging doesn’t sag too much.
Do you have any idea on what sort of settings I should be using or somewhere I might read up on settings and in general what they do?
I tried a line height of 0.21mm which seems to be the lowest it will go to and I still have the same problem in the slice
The slicer/printer will have trouble processing line widths smaller than the .4 nozzle where a min is around >.38mm You can get smaller with a .2 nozzle but it’s going to take a while.
Change the wall type to Arachne, this ‘may’ improve things. You may need to turn on advanced mode.
I’ve changed the Wall generator setting to Arachne as well as increasing the diameter of the bristles to 0.4mm (I did increase the amount of bristles to conform to one every 0.5mm in each direction) but here we’re…
Now I’m looking for the restriction to do that 5mm test print!
in the slicer, prepare, then the move arrows, and push object down through build plate (blue arrow). If you then slice, it will only slice that above the plate.
Did you try leaving “Wall generator” to “Classic” mode and turning “Detect thin wall” on in the Strength tab ?
DUDE!!! I know your new but you are wasting far to many of your own mental CPU cycles overthinking this.
What are you waiting for? Press the damned print button already and get it over with. I promise you, the filament police won’t raid your house if your print isn’t perfect. 
A sentiment I often am posed - The first print is on!
No, but that will be first on the list if the quality of this one is unacceptable
