Create Profile with maximum Speed (but still stable parts - good layer adhesion)

shoe · December 13, 2023

Hi,

is there a general guide as to how to tune Cura's printer profiles to get maximum speed with acceptable quality? I noticed that you can increase things like print speed to a point where the textfield turns red. Does this mean you can go to "yellow" and it is still okay?

I assume print temperature should be increased as well since extrusion is much faster.

I dialed up Print Speed to the highest value until it was not red. When slicing the print duration was much smaller. Then I also enabled "Print acceleration" and doubled the "Print Acceleration" value. When slicing, times did not increase. Very odd, no?

Anyways, is there a good way to max out the speed of your printer while keeping the strength of the part mostly intact?

Slashee_the_Cow · December 13, 2023

7 hours ago, shoe said:

is there a general guide as to how to tune Cura's printer profiles to get maximum speed with acceptable quality? I noticed that you can increase things like print speed to a point where the textfield turns red. Does this mean you can go to "yellow" and it is still okay?

I assume print temperature should be increased as well since extrusion is much faster.

I dialed up Print Speed to the highest value until it was not red. When slicing the print duration was much smaller. Then I also enabled "Print acceleration" and doubled the "Print Acceleration" value. When slicing, times did not increase. Very odd, no?

Don't focus on speed. Haste makes waste, in this case literally, with failed prints.
Red means "you can't do this", like print beyond the maximum speed a printer can, or print layers thinner than your nozzle can handle, stuff like that. I think in most cases it will refuse to slice if a setting is showing up as red.
Yellow means "you can do this, but you shouldn't" - it might be able to pull it off on paper (like print very thin lines without using a small nozzle) but there's no promise it'll work out well in the resulting print. You should only print with settings at yellow if you know what you're doing.
The print temperature setting needs to remain the same - whatever is appropriate for your material. It's the hardware that makes the difference here - your printer will manage its hot end to take into account the flow rate, but too fast and it just won't be able to heat up the filament in the time it takes it to get through it. Setting the temperature any higher wouldn't help because you're already hitting the printer's limit, and any slower areas will cook your filament.
You should print as fast as your material is designed for. Any faster and you'll get substandard results. For example TPU tends to need to print very slowly (I think mine recommends 20-40mm/s) because it's very rubbery and needs to properly set, or else the print head will pull on it and move it out of position, resulting in underextrusion and filament going everywhere around the plate.
Higher speeds are less accurate, even if your material and printer can handle the speed. Think of driving a car - even if your Ferrari can drive at 260km/h (in a closed environment, not on public roads, of course) you're going to have a lot less control than if you're driving at 80. When you get to a curve you're going to have to slam on the brakes (resulting a blob of filament where you brake) to be able to make it around safely, whereas the slower driver can just keep cruising at an even speed and laying down a much neater track of filament behind it than your Ferarri. My printer can go up to 250mm/s (which requires special high speed PLA), but I rarely take it beyond 100 for this reason.
Acceleration won't affect the print time much unless it's particularly low to begin with - it's just how quickly it goes up from a slow speed (like doing a corner) to max speed (like if there's a long straight bit just past the corner, or a long travel move). Too high and it'll have a similar effect to moving too fast in general - you'll tug at the filament and pull it out of position. Literally, I've had prints that were warped in spots because of how quickly it was accelerating away from some parts, when the rest of the print was fine.