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Variable acceleration and Jerk

Posted: Wed Feb 07, 2018 5:27 pm
by Ret
Hi all,


Idea:

I suggest S3D add a feature that gives us independent control over the acceleration and jerk of the following features: Top layer, Bottom layer, Inner shell, Outer shell, Infill, Support, and typical travel.




What this will accomplish:

By allowing us control of each individual feature listed above, we can speed up the process for some features, and slow it down for the other that require slower acceleration and jerk.




How this could benefit you:

Speed up infill printing.
Speed up printing of the inner shells.
Speed up normal travel.
Better bed adhesion with lower accel/jerk
Better outer shell and top layer quality.
Optimize the accel/jerk of a second extruder printing designated support material (PVA HIPS)
Overall, faster print completion with the same external quality you have, or better!
More accurate print time estimates
And many more benefits!

------------

Another slicer I use just came out with a feature similar to what I am suggesting, and it was really amazing! My prints came out a lot nicer and the build time was shaved down. I printed a 3 hour part and shaved off about 25 minutes yet the surface quality was much nicer than previously without the feature enabled.


On a side note, if S3D implements it all correctly, this will also help get more accurate print completion times which we all desperately need!


Please do give this a consider since it would be quite beneficial for better quality, faster printing, and more accurate print completions times.

Re: Variable acceleration and Jerk

Posted: Thu Feb 08, 2018 3:05 am
by rrdavis
I've been doing this for years in S3D. They already let you add custom code for each feature type using their custom scripting.

{REPLACE "; outer perimeter\n" "; outer perimeter\nM204 S500\n"}
{REPLACE "; inner perimeter\n" "; inner perimeter\nM204 S1000\n"}
{REPLACE "; solid layer\n" "; solid layer\nM204 S800\n"}
etc

Just add whatever modifications you need for each feature type

Re: Variable acceleration and Jerk

Posted: Thu Feb 08, 2018 5:32 am
by Ret
Thank you for that information, I wasn't aware of it. Although that is helpful, its a little limited and impractical. If they did implement this, as I said, it could assist in making print time more accurate as well as providing a simple way to change accel and jerk without post processing. I'm sure its not going to be a super high priority for them but I see it as being a fairly simple feature to implement.

Re: Variable acceleration and Jerk

Posted: Fri Feb 09, 2018 3:24 am
by rrdavis
Why is it limited? You can customize the acceleration for any feature type that the software uses. I've been using it for years and it works great. Not sure what more control you would actually need...

Re: Variable acceleration and Jerk

Posted: Fri Feb 09, 2018 5:46 pm
by Ret
Well, right off the bat I don't see how to control top and bottom layers independently. They seem to be merged into "solid layer". Bottom layers could be sped up a lot more than top, so I see a use in that.

Re: Variable acceleration and Jerk

Posted: Tue Feb 27, 2018 12:13 pm
by SDX
I made one with Jerk-settings, too:

{REPLACE "; inner perimeter" "; inner perimeter\nM204 S1500\nM205 X20 Y20"}
{REPLACE "; outer perimeter" "; outer perimeter\nM204 S500\nM205 X7 Y7"}
{REPLACE "; solid layer" "; solid layer\nM204 S700\nM205 X10 Y10"}
{REPLACE "; infill" "; infill\nM204 S1500\nM205 X15 Y15"}
{REPLACE "; support" "; support\nM204 S1500\nM205 X20 Y20"}

M204 = Acceleration
M205 = Jerk

You have to set the values for your needing.

Re: Variable acceleration and Jerk

Posted: Mon Apr 16, 2018 2:59 pm
by Tailslide
Came here to ask for the same feature.. very happy to find this script !

I think there is value to including this in the GUI though.

Re: Variable acceleration and Jerk

Posted: Mon Apr 16, 2018 6:00 pm
by airscapes
can live with the script but would love to find the document that would explain the 2 parameters and why one would want it slower for this or that.. Can.t customize something if you don't understand how the changes will affect the outcome.. Wait.. that is also needed for ALL the GUI entries as well as stuff the is not implemented!! :D

Re: Variable acceleration and Jerk

Posted: Mon Apr 16, 2018 6:20 pm
by airscapes
Sorry, just did a search though some gcode and dont' see M204 or M205 anywhere. What are these parameters set to as default?

Re: Variable acceleration and Jerk

Posted: Mon Apr 16, 2018 7:03 pm
by Ret
It most definitely should be in the GUI!

As for the values; The values are set by whomever configured/developed your firmware. Send M503 to your printer via USB and it should return a bunch of information on your printer's firmware settings. In that data returned, you'll see the acceleration and jerk settings they have predefined.