Print times longer than Cura  

RE: Print times longer than Cura

Check your max volumetric flow rate.  There’s one under filament settings and one under printer settings.  It’s probably putting a cap on how far Prusaslicer will let you print.

RE: Print times longer than Cura

Thanks, I will try that.

RE: Print times longer than Cura

The one in filament settings is set to 0 to disable the cap. The one in print settings is 15, so how would I find a good amount for it?

RE: Print times longer than Cura

It is probably MVS as mkoic mentions.  Could also be cooling thresholds too depending on part size. 

Please read this thread https://forum.prusa3d.com/forum/prusaslicer/speeding-up-prints-via-layer-height-and-width/   where the user was having problems with a similar issue in that thier changes were not speeding things up as they expected.

RE: Print times longer than Cura

There are a lot of parameters effecting the print speed, a lot. And you actually compared print times not speed really, which adds a lot of parameters to the mix. So if you really want answers you need to compare the settings and perhaps the gcodes from cura and slicer. If you want help, you need to post a test project including all your settings for the same model in both slicers.

Until then it's like: I bought a new vehicle but yesterday it took longer to drive to my in-laws than with the old one. Why is that?

RE: Print times longer than Cura

So I matched as many Cura and Prusa settings as I could and now Prusa is printing much faster! However my print times are way faster than PS’s estimation. All I did was download a profile for my printer and it sped up but I have to rely on the printer’s estimate after about 10 minutes of printing. Any idea on how to fix that? Thanks!

RE: Print times longer than Cura

As mentioned previously for these sorts of issues we would need a copy of a saved Prusa slicer project file. A project saved from PS is a complete snapshot. It allows us to examine all the settings you have used. Especially with random ones you have downloaded from the internet. 

Dont forget to Zip up any files or they won’t attach. 

RE: Print times longer than Cura

Are you aware that you didn‘t even bother to tell us what printer you are using, Joey? How should anyone work out the variables without you providing the constants?

RE: Print times longer than Cura

Don't use Cura that much but if anything, Cura takes a bit longer than Prusa. 

RE: Print times longer than Cura

My bad, I guess that’s also a part of it lol. I’m using a Sovol SV06 Plus with a Klipper screen. The profiles I downloaded are Ellis Print SuperSlicer profiles translated to PS which I’ll link here. Ill upload an example project when I get the chance.

RE: Print times longer than Cura

I’ll upload it when I can but it won’t be for about an hour or so.

RE: Print times longer than Cura

Here is an example file. Sorry if its the wrong type, im kinda a noob.

RE: Print times longer than Cura

Your example file needs to be Zip Compressed, or the forum quietly deletes it from your post. 

regards Joan

RE: Print times longer than Cura

Sorry, I attached it wrong. Here is the file.

RE: Print times longer than Cura

I have used both PS and Cura with the Prusa MK3S for a number of years now.  I also use Cura on an Ultimaker printer.  Cura and PS both have their strong points and weak points.

The Cura that I have is descended from an in-house distribution from our local makerspace several years ago, and was optimized for their Taz (Lulzbot) printers.  I was surprised to see that it had a Prusa MK3 profile on it, and I tried it, but it was nasty and produced poor prints.  The speeds (travel and print) were too fast, among other things.

I carefully adjusted most of the Cura parameters to be the same or similar to those in the ca. 2000 PS and I got it so with basic prints, the results were about the same with both.  I've since versioned both of them several times but kept the now-four-year-old Prusa printer profile.

Although it varies from print to print, the print time, from button press to finished print, is about the same on the Prusa printer.

One thing that I have noticed, and this is really not on-topic, is that on an apples-to-apples comparison with the same print, such as the test cube, the Ultimaker (S5) will typically take 10-15% longer from button press to finished print than the Prusa. 

RE: Print times longer than Cura

Thanks for attaching the file Joey. I have some follow up questions please.

What is the estimated print time using Cura and if printed what is the actual print time ?
When you print the gcode from PS does the actual print time match the estimate or is the estimate way longer.  Basically Im trying to determine if its just the estimate in PS being off or the actual print.

There are a couple of things to note from the project file.
There is still an active MVS setting of 15 in the Print profile.  While the filament one has been set to zero the other is not.  I don't know if 15 is a suitable value for your printers hotend/filament combination.  Changing it doesn't make much difference anyway as the max print speed value in print settings then starts to be the limiting factor.

If its just an estimate difference then naturally that is not going to be very accurate.  In Printer Settings>Machine Limits you have the basic values from what looks like the base profile of a Sovol.  Those are set to be used for the time estimate.  The time estimates use Marlin as the base type with those machine limits configured in there to work out the time estimates.  If you change it from Use for Time Estimate to Ignore then the estimate changes from around 47m to 23m.  

RE: Print times longer than Cura

So the print time in PS actually is longer than the prints, sometimes even double the time. Also the Marlin for time generation, are you saying that it’s an option that can be changed? If so where do I change it? 

RE: Print times longer than Cura

You keep stressing, that you are kind of a noob. So here are some basic things about speed calculation:

There are 3 different kinds of printing time: 1. the time your slicer of choice calculates when generating the g-Code. 2. the time remaining (plus time elapsed) your printer or your server displays during printing. 3. the actual time it took to print when finished. Like when you plan a bike trip. 1. what your route planner calculates, 2. time to destination (plus time elapsed) on your bikes nav. 3. the time it actually took you when you are at your destination. These 3 will never be exactly the same when printing or biking for similar reasons.

First. „Slicer is faster/slower than Cura“: Is it? Are you faster on your bike trip when calculating with Apple Maps than you are when using Google Maps? That depends. See, you need to look at the route‘s details are the two calculated routes exactly the same? Most certainly not. Even if they are, the calculated time depends on the speeds taken into account. If one uses higher speeds or acceleration the calculated time will be shorter but if the values do not match reality you will not be faster you just think you will before starting and while your on your way the discrepancy will be less and less until you reach your destination.

Enough biking, back to printing: All the speed limiting parameters in the slicer apps are there for a reason, some to model physical limits of the printer (like max speeds and acceleration) some to model physical limits of your filament/extruder (like volumetric speed) some to optimise speed vs. quality (like perimeter speeds, or infill style and percentage, number of perimeters). The first two kinds of limits should be left alone, if you change them your calculated printing time will of course be shorter but since those are physical limits your print will actually not be that fast or fail completely - there are safety margins of course and you could try to gain some speed by reducing, but I would not recommend that. That leaves us with the third kind of parameters speed vs. quality, you can play with these as much as you want, every change will result in changes of the path and speeds your printer takes and therefore the printing time your slicer calculates. You will never ever be able to find settings in slicer and cura which result in exactly the same path for the same model, if you would and set the speeds and limits to be the same the calculated times would be the same as well. If your printer actually finishes the job in that time depends on the limits being set matching reality.

Bottom line: Set your physical limits to match reality in both slicers and the rest according to your and your model‘s needs and see what you get. If times differ it‘s because paths differ, you need to decide which path to take. Faster is not necessarily better…

RE: Print times longer than Cura

Generally good advice Robin.  

In the OP's case though they have Klipper selected as type.  With a properly set up klipper install where you have done all the resonance tests etc it will work out what the maximum speeds are for that setup.  In general those will be higher than a 'normal' set of values for standard printer firmware.  Those will then be defined in the klipper config file for that printer. 
Those values should be used to update the ones in Printer Settings > Machine limits to slightly make the estimate more realistic.  They arent 1:1 name wise so you have to work out which ones apply.  Then again if they are 'new' then messing around with Klipper is also going to be a world of hurt potentially.  That alone is way more complex then configuring a slicer and you can over stress your printer as you have a lot more control.

As for the specific questions about the time estimate, you cant change the fact that PS uses the marlin type for the estimate.  That's internal.  You CAN however tell it to not use the values in machine limits.  Its in that same section and is a dropdown called How to Apply limits.  It has emit to gcode, which actually includes the M20x codes for Marlin firmware use into the gcode file (which will do nothing for a klipper setup unless you have specifically made your klipper install make use of those M codes which by default they don't), Use for time estimate, in which case PS will use those maximum speeds to do the math for the estimate but wont include the actual M codes into the gcode file,  and Ignore.  In which case it wont use them at all.  For klipper thats an option though as it does tend to result in a shorter estimate.

Btw all these setting are not available or shown if you are in Simple mode.  You must be in Advanced or Expert mode.

I've got a klipper based printer and even using the klipper values in the machine limits the machine regularly finishes 30-40% faster than the estimate.  Not really a problem as I know my prints are going to be done quicker than it reckons at slice time.