PrusaSlicer very slow - how to speed up?
I have, as of last year, a Prusa i3 Mk3. I previously used a Replicator 2 for several years, and used Simplify3D for the slicing software. As I have around 550 models (as designing wargames models for 3D printing is my day job), I have continued to use that, simply because of the supports.
However, with some models, I have been having some sticking issue (wheels in particular, as well as small parts). Not even always just to the plate, but sometimes, some small parts on a base don't stick to the base.)
I am at the moment, for reference, specifically trying to print a variant of a 144th-scale Boxer APC
Similar to the one pictures here (albiet this one printed as one of the last models we got out of the Replicator 2 before it finally died last year), which is about 55mmx25xxm20mm for a ball-park reference.
As an experiment to try and solve that problem, I tried Prusa Slicer this afternoon (the latest version of 2.3 with the paintable supports - that was a mandatory thing, since it would be HIGHLY impractical to laborously do the supports again on PrusaSlicer without some level of fine control for 550 models).
It still puts rather more supports on than is necessary (even adjusting the settings from a relevant post on this forum below), but it stuck. The first test seemed okay, coming it at pretty much bang-on the predicted time, and more or less the same time as Simplify's prints.
However, I then realised that the model I'd done (at the same speed as the Rep 2 did, and with Simplify when it worked) was at 0.2mm res, not the 0.1mm I need for production. Switching to 0.1mm increased print time from about two hours to three-and-a-half using Prusa slicer, and on smaller models, the time is doubled.
While I have been having some annoying sticking issues with one or two models in Simplify, the majority have been printing fine at Simplify's default 80mm/s speed. (Outline speed is 50%, solid infill and support structure 80% and x/y axis is 200m/s.)
The vastly increased print times (on the order of +50% to double) of the default PrusaSlicer settings is not something I can live with (since it means a direct proportional increase in price to my models based on print time). A small increase would be acceptable if it resolves the sticking problems, but not something of that magnitude. One feels there must be a decent compromise point.
As the settings are not the same between Prusa and Simplify, I'm not 100% sure what needs to be increased.
I can see on PrusaSlicer's Speed tab:
perimeters
small perimetres
external perimetres
infil
soild infil (which I assume equates to simplify's "solid fill underspeed," especially as both are the same 80%)
top solid infil
support material (which I assume equates to simplify's "support matrial underspeed," also both 80%)
support material interface
bridges
gap fill
ironing
speed for non-print moves (which I assume equates to simplify's "x/y axis movement speed" and set to 180mm/s to Simplify's 200mm/s)
first layer speed
and then some options on acceleration.
Simplify 3D has under its speed tab:
default printing speed 4800mm/min => 80mm/s
outline underspeed 50%
solid fill underspeed 80%
support matrial underspeed 80%
x/y axis movement speed 1200mm/min => 200mm/s
z axis movement speed 1000mm/min => 16.67mm/s
Speed overrides: Adjust printing speed for layers below 15s set to 20%.
Using generic PLA; as of yesterday, first layer temp set to 215ºC, subsquent to 210ºC. (Since it was defaulted to 200ºC on Simplify, so I copied PrusaSlcier's heat settings; while the quality was not notably any different at 200,, this was an attempt to deal with some of the sticking issues.)
So I'm not sure as to which Prusa settings equates to the default print speed?
Perimeters? Which would make "external perimeters" equivilent to Simplify's outside underspeed? (Prusa had that at 45mm/s to 25mm/s to Simplify's 80mm/s to 40mm/s...?)
I am seeking advice, as while some level of experimentation is likely going to have to happen, I am hoping that some advice might cut down the amount of time required, so I can be usefullyrunning stuff off again; any advice would thus be appreciated.
(Incidentally, if there IS a way to translate the supports in Simplify across to Prusa, it would be useful to know, but obviously, I highly doubt that possibity exists.)
RE: PrusaSlicer very slow - how to speed up?
Good morning,
looking at your S3D settings, I believe you made an error
Simplify 3D has under its speed tab:
default printing speed 4800mm/min => 80mm/s (If this is correct)
x/y axis movement speed 1200mm/min => 200mm/s (This cannot cannot be 1/4 of the speed and 2.5 x as fast)
have you seen this Prusa Slicer information?
https://help.prusa3d.com/en/category/prusaslicer_204
moving on to your real question... why is Prusa slower than S3d?
I don't know... (Yeah... not very helpful, Sorry... )
Are you comparing S3D estimated time against Prusa Estimated time? IIRC S3D estimates were a bit optimistic, on my Prusa
Actual - 'real print times' for the same model sliced on the different slicers, is the parameter to compare...
maximum volumetric speed is possibly the ultimate potential limit... for PLA this should normally be 15 mm3/s (PETG usually has a slower speed). I suspect this will not be an issue in this case because you have lower layer heights and a fair amount of detail (Both of which restrict ultimate print speeds and thereby filament requirement speeds... but it's worth checking
Retraction and Z hop do you need the default values? I usually reduce mine... 0.4mm retraction 0.4mm (Time spent leaping about is not printing time, more intricate models tend to have more retractions)
In the Prusa Slicer infill section there is a 'Reducing Print Time' section... You may consider
'Combine infill every' 2 or three layers.... the external perimeters need to be 0.1mm layer height, could the infill be 0.2mm or 0.3mm? this may reduce your print time.
'Only Infill where Needed' some details may not actually need infill, this option may also save print time...
in the Prusa Slicer infill section, consider ticking 'Only retract when crossing perimeters'
Are you actually printing the same model (I know you are using the Same STL but Prusa Slicer and S3D use different settings to complete the sliced models can you compare the material weight in both for instance... If the Prusa Slicer version is significantly heavier, then it has more plastic to lay down, which is likely to take longer) Maybe you have more plastic in supports?
If model weight difference, is the case, you may need to look at the perimeter/ top and bottom layers/ infill type / infill percentage settings rather than speed settings
Are you using the latest Prusa Firmware? in the printer to match the latest slicer?
there have been reports of older firmware taking longer to print, with gcode created by later prusa slicer versions. (I haven't paid a lot of attention to this but it may be a 'Linear Advance' conflict...)
I hope these points will help you narrow the gap between the slicer settings
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: PrusaSlicer very slow - how to speed up?
@joantabb
Typo - 12000mm/mins, which equates the correct 200mm/s.
I am comparing logged Simplify times. I log estimated and actual print times as a matter of principle (indeed, actual print times are the primary metric by which I set my product's prices) - Simplify's estimates are indeed under the actual print times, but I have the actual time.
I also log material length and weight estimates. The Simplfy slice with raft used an estimated +20% more material (estimated 5289.3mm and 15.89g, verses the PrusaSlicer (with no raft) 4220mm and 12.59g), but the Prusa has an estismted print time of 3h 23m (or 3h 25m on stealth).
So in is projecting it will take PrusaSlicer will take 35% longer to put 80% of the material down.
(Looking at it, Simplify is also set to 30% infil instead of PrusaSlicer's 15%).
I flipped the settings as suggested to combine three layers of infil and turned on only infuil where needed - that dropped 15m off the projected print time (but that's still three hours 15 mins). Turning the non-print speed up to 200 from 180 made a difference of about amniute (I didn't expect it to).
Flipping up the PrusaSlicer perimeter speed from 45 to 80 did not appear to make any significant difference.
Here are compartive screencaps for features:
And movement speeds:
If that might of assistance (as I had not though to check that last night or this morning).
From that, it appears that Simp;lify is just running the perimeters 25% faster at least (though still well below the both 45 and 80mm/s).
Checking the since, PrusaSlaicer is now running the inner support materials at 80mm/s, which Simplify is still running the inside at about 50mm/s.
So now I'm REALLY not sure what settings to try with, since the first obvious one clearly won't have an effect, as neither print approaches it.
RE: PrusaSlicer very slow - how to speed up?
I hate to do this, but I'm going to suggest taking a look at ideaMaker as a slicer. It sounds like you're having a lot of issues with supports. I went through several slicers and configurations when printing a large number (500+) of 1:100 vehicles last year. After going insane trying to figure out good support settings to eliminate exactly the issue you're dealing with, I discovered ideaMaker can produce supports that are easy to remove (literally seconds for most vehicles) and look markedly better than PrusaSlicer's current support undersides. It also provides a custom support interface that is very much like Simplify 3D's. All of this in a software package that is free, although not open-source.
Here are some samples I did in 1:600, 1:285, 1:200, and 1:100 scale recently:
A few tips:
- Tilt your models at a slight angle to reduce that stair-stepping effect on the front deck. You may need more supports for this, but it makes a big difference in models at these scales. The exact angle might vary by model.
- If you have problems with things like wheels failing, even with supports, trim 0.25mm off the bottom to provide some flat surface to improve adhesion. If you are designing your own prints, you can design in a bit of "flat" tire squish to do this.
- If you have a lot of fiddly bits with adhesion problems, a raft might help. I really hate to use rafts, but they can be useful in specific circumstances like this.
- If you're really after fine detail, you might consider a resin printer.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: PrusaSlicer very slow - how to speed up?
If you have a sample model available, I'd be happy to give it a go in ideaMaker to show the results. Also happy to provide suggestions for printing in PrusaSlicer.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: PrusaSlicer very slow - how to speed up?
@aotrs-commander
looks like Bobstro has some ideas...
the Prusa first layer speed is also very slow, 20mm/s
good luck, 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