Printing at 300 mm\/s is something quite impressive. You’ve probably seen it at least once on a few printer specs or on a video. Are they really printing at this speed? Maybe, but it is very hard to verify. Printing at this speed is possible but under certain conditions.<\/p>\n
This blog will explore all the requirements to verify, understand and configure a printer so it can reach 300 mm\/s or as close as possible. It might also be very useful if you are building your printer.<\/p>\n
This first part explores the components involved in both speed and acceleration performance. It also compares the two most commons 3D printer types.<\/p>\n
The second part<\/a> will discuss the measurable and calculable limits of the parts explained in this current blog.<\/p>\n The third part will show firmware and slicer configuration, real experiments, benchmarks codes, and prints.<\/p>\n Before heading to hardware limits, let’s make sure we understand the basics. There are some very specific details used in 3D printing that are pretty unique, and misleading to what is seen in the industry standard, see « Jerk » below.<\/p>\n Speed is the easiest parameter to get, we see it in many aspects of our lives: driving ( km\/h ), downloading ( kB\/s ), etc. A 3D printer moving at 100 mm\/s require 1 second to move 100 mm away. However, the speed does not change instantaneously, it slowly gets faster until it reaches it’s target speed. This transition is called acceleration.<\/p>\n <\/div><\/div>\n Acceleration is a little bit harder to get. It is the change of speed in time. For example, a car start at 0 km\/h and want to reach 100 km\/h. It starts moving slowly and then reach 100 km\/s in 10 seconds. It means that each second, the speed increased by 10 km\/s, so the acceleration is 10 km\/h\/s. This unit can be confusing, but it is basically a length \/ time^2, this is the reason why you see acceleration values in mm\/s^2 in 3D printers. Since the components are light and small, acceleration can be very high compared to a moving car.<\/p>\n Based on Marlin firmware, the standard acceleration is 3000 mm\/s^2, which is a good value for a rigid setup. A 3D printer would only require 0.033 seconds to reach 100 mm\/s. Some manufacturers reduce acceleration below 1000 mm\/s^3 to reduce corner ringing and other imperfections.<\/div><\/div>\n As mentioned above, jerk is misleading in 3D printing. In industrial motion application, jerk is the variation of acceleration, so the same logic can be applied between jerk and acceleration than we applied between acceleration and speed. Its unit can be mm\/s^3.<\/p>\n Jerk is not used in trapezoidal acceleration profile, which is the motion profile used in 3D printers. This means the acceleration changes abruptly.<\/p>\n The jerk we see in 3D printing has units of mm\/s. As you probably remember, these are speed units. Actually, in 3D printing, jerk is used as a threshold for minimum speed requiring acceleration. For example, a standard jerk value of 20 mm\/s will make any move below 20 mm\/s without acceleration. This happens often when an infill line is very short and the 3D printer will vibrate extremely quickly.<\/div><\/div>\n Motion profile is controlled by the firmware. The most common profile is trapezoidal because the logic is very easy to program. The acceleration is constant, either positive (accelerating) or negative (decelerating). Being easy to program has few disadvantages. Compared to other known motion profiles types, it reaches the lowest acceleration for the same motor power. Also, the movements can be very rough, because the jerk is considered infinite.<\/p>\n Advances motion profile can get smoother motion, higher acceleration, and higher velocity than trapezoidal profile, such as cycloidal and polynomial. You may want to read this great article<\/a> about jerk, acceleration and motion profiles.<\/div><\/div>\n\n
\n\nMotion basics<\/h1>\n
Speed<\/h2>\n
Acceleration<\/h2>\n
Jerk<\/h2>\n
Motion profile<\/h2>\n