Jerk and Acceleration Settings

DjDemonD

They look fine, see how it runs, its good to push it just for a test, to see how far it can go, then you know how much headroom you have when running at much more more sensible settings.

deckingman

I kind of put my thoughts in the other thread that Corexy posted but regarding accelerations, try something like diagonal infill on a 100mm x 100mm cube (or 50X50 - doesn't really matter) and just observe how it looks as the moves get shorter and shorter. I'd think that at 9,000 it'll try and shake itself to bits or at least look pretty alarming. If it does, reduce it down until the speed "looks right". I've found that 1200 acceleration works well for my CoreXY (but it has a seriously heavy hot end).

Corexy

@deckingman:

I kind of put my thoughts in the other thread that Corexy posted but regarding accelerations, try something like diagonal infill on a 100mm x 100mm cube (or 50X50 - doesn't really matter) and just observe how it looks as the moves get shorter and shorter. I'd think that at 9,000 it'll try and shake itself to bits or at least look pretty alarming. If it does, reduce it down until the speed "looks right". I've found that 1200 acceleration works well for my CoreXY (but it has a seriously heavy hot end).

It's hard this…you get such wildly different answers.

I'll play it safer:

M566 X900 Y900 Z12 E800 ; Set maximum instantaneous speed changes (mm/min)
M203 X12000 Y12000 Z1200 E8000 ; Set maximum speeds (mm/min)
M201 X2000 Y2000 Z20 E500 ; Set accelerations (mm/s^2)

I've never had any problem with the stepper motors like skipping or any thing, they seem strong. I know the standard Zortrax extruder setting was 400mA, but they had trouble with it and some people including myself wound it up to 600mA. Over 600 it started to show wavy patterns in the prints.

There's also one speed I can't get to change, the Z axis when it homes at the start of a print. I can get it to move faster when I move it manually, but the homing speed is always the same, and it's too slow and makes an annoying resonating noise.

I just want to step it up 50%. Can anyone tell me where I find that?

deckingman

You will get wildly different answers because the speed and accel settings will be wildly different depending on machine kinematics and to a large extent users personal preferences. Personally, I find the best approach is simply trial and error.

Ref homing speed, it's the F parameter in M558 where you define the probe type. https://duet3d.com/wiki/G-code#M558:_Set_Z_probe_type.

HTH

Ian

Corexy

@deckingman:

You will get wildly different answers because the speed and accel settings will be wildly different depending on machine kinematics and to a large extent users personal preferences. Personally, I find the best approach is simply trial and error.

Ref homing speed, it's the F parameter in M558 where you define the probe type. https://duet3d.com/wiki/G-code#M558:_Set_Z_probe_type.

HTH

Ian

Yes that helped immensely thank you.

So good not to hear that horrible resonating noise at the start of each print.

Cheers,

Corexy

And….......it turns out it was just a crap roll of filament.

Changed my expensive roll of Verbatim for a roll of cheap Aussie generic, and knocked out a near flawless print.

Now running a roll of Colorfabb and that's beautiful too (but need very different start and print temps than the others).

One thing I'm learning after years of only using ABS is that different brands, and even rolls of PLA vary much more in settings requirements and print quality.

So it's worth trying out different filaments, cheap can be good and expensive can be crap.

deckingman

Interesting your observations about Verbatim filament. I ordered some "common or garden" PLA but the supplier was out of stock of the particular colour I wanted so they sent me the more expensive Verbatim instead at no extra cost (big deal). Long story short - I'd rather have had the cheap "crap" and won't be using Verbatim again.

Corexy

@deckingman:

Interesting your observations about Verbatim filament. I ordered some "common or garden" PLA but the supplier was out of stock of the particular colour I wanted so they sent me the more expensive Verbatim instead at no extra cost (big deal). Long story short - I'd rather have had the cheap "crap" and won't be using Verbatim again.

I have had no luck at all with Verbatim in PLA or ABS.

I also won't be using it again.

Whitewolf

I am running a Bowden direct drive extruder and my results might surprise some people but I can attest these settings work very very well.

I do not have a part cooling blower and have successfully completed several benches like this one with PLA: https://www.thingiverse.com/thing:1619976 and 3dbenchy…. I do not have any stringing, oozing or blobbing like when I started.

Warning, I need to tame some of these back as some of them cause my printer to bang around depending on what is being printed but the prints come out amazing

M566 X9000 Y9000 Z12 E9000 ; Set maximum instantaneous speed changes (mm/min)
M203 X12000 Y12000 Z375 E12000 ; Set maximum speeds (mm/min)
M201 X9000 Y9000 Z150 E6000 ; Set accelerations (mm/s^2)
M906 X850 Y950 Z950 E950 I30 ; Set motor currents (mA) and motor idle factor in per cent
M572 D0 S0.1

My Slicer is simplify3D and the bridging in it sucks, most overhangs in these models never get bridge mode enabled but I was still able to get amazing results none the less.

Slicer settings:

62mm/s print speed
115mm/s retraction speed
1.85mm retraction
0z hop
Outline direction: Outside in
Outline overlap: 10% (too much overlap on a well tuned printer will cause bulging like you see I found 10% to be ideal for well tuned estep and filament temp)
Only retract when crossing open spaces is unchecked
force retraction between layers is checked
perform retraction during wipe movement is checked

My kids ran off with my benches but the results with snappy XY and snappy extruder completely eliminated any stringing and successfully connected non bridge parameter outlines (S3D bug, they should be treated as bridges) and it did so without the assistance of cooling and a 205c temp on PLA.

Now I just need to find the best jerk settings so my printer does not sound like its banging with every movement of the axis…. I am finding fast moves are the best way, it makes for ultra sooth quality prints with no defects but I need to find the sweet spot for jerk settings to make it maintain the quality that the high speed is giving

Whitewolf

P.S. I have a sheetmetal frame Davinci Pro so your results could vary depending on frame and motors but this thing seems to respond well to speed.