# Slic3r Acceleration control **URL:** \ **Category:** Software\ **Created:** [July 20, 2013, 11:06pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214 "2013-07-20T23:06:22Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![eric\_german](https://avatars.discourse-cdn.com/v4/letter/e/7ab992/32.png) [@eric\_german](https://forum.lulzbot.com/u/eric_german)\ **Post date:** [July 20, 2013, 11:06pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/1 "2013-07-20T23:06:22Z")
Hey all, Can anyone give more info on the Acceleration control (advanced) options in slic3r’s speed panel? Does this override the firmware? Ought I move it above 2000 mm/s2? ---
**Author:** ![jebba](https://avatars.discourse-cdn.com/v4/letter/j/9e8a1a/32.png) [@jebba](https://forum.lulzbot.com/u/jebba)\ **Post date:** [July 22, 2013, 2:53pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/2 "2013-07-22T14:53:38Z")
It overrides the firmware. I’d be interested in hearing your results. 🙂 ---
**Author:** ![1013](https://avatars.discourse-cdn.com/v4/letter/1/8edcca/32.png) [@1013](https://forum.lulzbot.com/u/1013)\ **Post date:** [July 22, 2013, 4:09pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/3 "2013-07-22T16:09:21Z")
I doubt it will make it accelerate faster than the firmware’s limits…but it can make it go slower I would imagine (just like max speed settings). I have not messed with it at all…the effort to set it up correctly just doesn’t seem worth the small gain IMO. But go for it is you have the inkling. ---
**Author:** ![jebba](https://avatars.discourse-cdn.com/v4/letter/j/9e8a1a/32.png) [@jebba](https://forum.lulzbot.com/u/jebba)\ **Post date:** [July 22, 2013, 5:52pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/4 "2013-07-22T17:52:33Z")
Actually, I think it will override the firmware’s settings, even if faster. ---
**Author:** ![eric\_german](https://avatars.discourse-cdn.com/v4/letter/e/7ab992/32.png) [@eric\_german](https://forum.lulzbot.com/u/eric_german)\ **Post date:** [July 23, 2013, 12:51am UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/5 "2013-07-23T00:51:29Z")
Well i doubled perimeters to 4000m/s/s and it was sailing until it skipped steps (i think) on the y axis started printing 5 mm off on the y. ---
**Author:** ![t0b1as1](https://avatars.discourse-cdn.com/v4/letter/t/a9adbd/32.png) [@t0b1as1](https://forum.lulzbot.com/u/t0b1as1)\ **Post date:** [June 22, 2014, 2:46pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/6 "2014-06-22T14:46:49Z")
Can anyone say a bit more about this? What is the acceleration, and how come the values are so high i.e. 2000mm/s and so on… ---
**Author:** ![rufu5](https://avatars.discourse-cdn.com/v4/letter/r/f14d63/32.png) [@rufu5](https://forum.lulzbot.com/u/rufu5)\ **Post date:** [June 27, 2014, 5:33pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/7 "2014-06-27T17:33:15Z")
When you put an acceleration value foo mm/s^2 into slic3r, it will put this into the output file right before the designated print feature (infill, perimeters, etc): ```nohighlight M204 Sfoo ``` This will override the firmware setting, which can be found in the mechanical settings section of configuration.h of the firmware. It looks like this: ```nohighlight #define DEFAULT_ACCELERATION 500 // X, Y, Z and E max acceleration in mm/s^2 for printing moves ``` (you can find the firmware here: [http://devel.lulzbot.com/TAZ/Guava/software/current/Marlin/Marlin/Configuration.h](http://devel.lulzbot.com/TAZ/Guava/software/current/Marlin/Marlin/Configuration.h) ) However, it will not change the jerk setting. Jerk is [http://en.wikipedia.org/wiki/Jerk\_(physics)](http://en.wikipedia.org/wiki/Jerk_%28physics%29), or the rate of change of the acceleration. The line in the firmware that sets the maximum jerk looks like this: ```nohighlight #define DEFAULT_XYJERK 8.0 // (mm/sec) ``` and can be changed from 8 mm/s^3 to something else by navigating through the LCD like control\>motion\>Vxy-jerk and then changing it (don’t forget to use “store memory” if you would like to make the changes persist through a power cycle). Or by running ```nohighlight M205 Xfoo ``` from the pronterface terminal. Jerk is the rate of change of the force applied to the carriage (since F=ma, force and acceleration are proportional). Even if you crank your speed and acceleration settings to over 9000, a lower jerk setting will correspond with a longer overall print time, because it is limiting the rate of change of the acceleration. ---
**Author:** ![printeverything](https://avatars.discourse-cdn.com/v4/letter/p/f14d63/32.png) [@printeverything](https://forum.lulzbot.com/u/printeverything)\ **Post date:** [December 1, 2014, 7:50pm UTC](https://forum.lulzbot.com/t/slic3r-acceleration-control/214/8 "2014-12-01T19:50:37Z")
After setting the acceleration to 5000-8000 mm/s^2 and skipping y steps (1-2 mm near the 5mm z height), support told me they use max 1800 and low 1300. I had set some to 200 and noticed it crawling, after reading 500 is the default that helps a lot. Was trying to set infill only to 1800 and slic3r kept erroring, it doesn’t like values of 0 for the others when one is set up.