grue19
Posts: 55
Joined: Sun Jun 30, 2019 12:06 pm

how common is it to change the extrusion multiplier?

i'm beginning to understand that extrusion multiplier, esteps and temperature are really tightly related! i have done a ton of 1st layer tests, .2mm high. i started getting pretty great results with the esteps cranked up above what i had calibrated, i calibrated from default of 95 to 103, but then turned up to 107. i do this under the scripts tab in the start gcode.

also, should i set extrusion multiplier to 1.0 when i am using the esteps? i used the macihne control panel to extrude the 100mm of filament so not sure if that took into account the extrusion multiplier?

in otherwords, maybe setting the esteps and leaving the extrusion multiplier set to the default of .9 for pla and my machine profile is OK? it seems like you can fudge it between esteps and extrusion multiplier?

as far as temps, i see that makes a big difference too, but not as much as extrusion multiplier or esteps.

right now i'm using .9 extrusion multiplier and 107 esteps which i judged by the many 1st layer tests i've done. my wall width is supposed to be .8mm and i'm measuring .84 on all 4 sides - it's consistent great! my nozzle is .4mm and i have its size set to manual and .4mm. although is there some thoughts on using a bit larger nozzle size in the slicer?

i also wonder if extrusion multiplier affects overall layer height, or setting higher esteps for that matter? so over time and height in a tall print the errors could add up and not be good!

sorry, lots to unpack here ha!

thanks,
horst.w
Posts: 861
Joined: Fri Oct 17, 2014 5:00 pm

Re: how common is it to change the extrusion multiplier?

... very common and really necessary!
Each material has its own conditions (e.g. ultimate elongation constant ... ) you can't justify but with the extrusion multiplier.


horst.w
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dkightley
Posts: 2405
Joined: Tue Mar 10, 2015 4:09 pm

Re: how common is it to change the extrusion multiplier?

I tend to partially....but not completely agree with this....

I've hardly had to make many changes to the extrusion multiplier. I've never had cause to even think about changing the esteps. I have, however had on a few occasions needed to adjust the temperature....but purely to ensure a particularly complex or small part needs printing.

Having said that, I only work in PLA and I always use plastic from one supplier.

Thinking technically about the extrusion multiplier......the value is used to adjust the overall calculation of the amount of plastic extruded throughout the whole extrusion process...and it is one of two values that do so.....filament diameter being the other setting. My experience of filament has shown that the diameter of the filament I use is very, very consistent.....and consequently, once I have settings tuned, I never have need to adjust either of these two settings.....even on changing rolls and/or colour.

Tweaking the esteps is totally unnecessary.....and in fact I would say is a really silly thing to do. You are essentially adjusting the x, y or z mechanical dimensions of the bed in relation to the dimensions the slicer thinks the bed is. The same would go for the esteps for the filament feed......you might as well drill the nozzle out with a larger drill as an alternative to changing the esteps!!

Bottom line......learn what the slicer settings actually do....and what the effect of changing them has. Then only change one setting at a time when trying to tune your settings. Never guess and twiddle at random!

Of course, what I've said here is purely my own opinion based on my six years of 3D printing. Others may....and probably will, disagree!
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net
grue19
Posts: 55
Joined: Sun Jun 30, 2019 12:06 pm

Re: how common is it to change the extrusion multiplier?

thanks. so this is why i'm just starting to now understand things - i'm making one change at a time and then printing ha!

so yeah, calibrating esteps on xy and z seemed really crazy to me because wouldn't the mfg of the printer know that already and program that into the software?! i mean, it's visible right there in my config.h file and on the printer's control box interface.

however then i tested the extrusion of 100mm of filament - but even in that there are variables - i assumed the best approach was through the nozzle at a certain temp. others have done it cold. and at what speed - does that make a difference? i know my printer came with a preset extrusion steps just like the xy and z axis movement steps.

ok, so my first layers since getting simplify3d have always been questionable. there are gaps between the lines it lays down as bottom solid infill. the brims/skirts are always guitar strings!

that's what has lead me here - i know my nozzle is just about perfect (?!) gap, .06mm from the surface and i have mesh bed leveling with marlin turned on and set it manually with that same gap using a feeler gauge.

i did try changing the extrusion multiplier from .9 to 1.05 to see if the 1st layers were any better and they weren't so maybe i needed to go more than 1.05. but i did try multiplier of 1.00 and set my esteps 107steps/mm and my 1st layer actually turned out well.

i did also try 5 degree increases in temperatures up to 210 anything above that the pla gets pretty goopy and stringy.

so that's when i started wondering about changing the extrusion multiplier and if that's a good thing or bad thing. i guess what i'm looking for like you said is to find the one or two settings i can always change or look at first, then move on to the next thing if needed.

ps i also tried raising and lowering the global z offset +0.04mm and -0.04mm which REALLY cuts it close if in fact my feeler gauge is .06mm and the mesh leveling is accurate. and besides a lot of people are printing with .1mm gap.
grue19
Posts: 55
Joined: Sun Jun 30, 2019 12:06 pm

Re: how common is it to change the extrusion multiplier?

well, i'm getting pretty decent 1st layers it seems and i did another one of those hollow cube prints with 2 .4mm walls and getting great width measurements with it. here's what i did. first started at extrusion multiplier of 1.10 and turned off my extruder esteps i had in the start gcode. then i printed that calibration cube and got wall width measurements of .91 - .92 ish. so based on calculation my new extrusion multiplier is .967 so i'll round that up to .97. anyway, the cube wall measurements are now .80 - .81. plus the height of that hollow cube is very nearly perfect 15.0mm. yeah, dpending on where i measure it ranges from 14.98mm to 15.12ish. but much better than before. also, i wonder if that could be due to mesh bed leveling - i changed my fade height in marlin from 10 to 20 to average out more at a finer gradation of height.

ok so my cube was great, now the first layer test i made .2mm high with .2mm layer and 1st layer of .2mm and % line width and % height both set at 100, the first layer test is pretty OK, it's like a piece of paper, all one piece and it measures in various places .20mm to .23mm so awesome!

i have only recently started playing with % 1st layer height and % 1st layer line width, but i also wondered about that - it shouldn't really be necessary and if it is, then the height really should only be the thing to change if you're doing say .12mm layers, but then the 1st layer height should be an even multiple of the actual printing height.

damn, i'm all excited now... it's working great and i don'thave to worry about esteps! i can just use that multiplier for extrusion!

thanks,
Jarhead
Posts: 9
Joined: Thu Oct 05, 2017 10:00 am

Re: how common is it to change the extrusion multiplier?

Depends on if you're just printing 'trinkets' or if you need things that actually "fit".

Look here:
https://mattshub.com/2017/04/19/extruder-calibration/
grue19
Posts: 55
Joined: Sun Jun 30, 2019 12:06 pm

Re: how common is it to change the extrusion multiplier?

thanks. good read. so i'm all set for multiplier and actual extrusion width. unfortunately i'm getting some major layer shifting and banding. something came loose - a belt or whatever, so time to revisit that. otherwise, the layers that are printing now before i get all the layer shifting are looking better than they ever have been! nice defined shape to them and evenly stacked on top of one another.

as soon as the printer starts jogging back and fourth like when printing an x y z cube, to make the indents for the letters, that's when i get the layer shifting. crazy - like i said something must be loose somewhere! i'll post up some picks. i think i'm heading in a really good direction!
wirlybird
Posts: 1374
Joined: Sun Jul 17, 2016 1:32 pm

Re: how common is it to change the extrusion multiplier?

I do not adjust the extrusion multiplier much after I find a value that works for a particular filament and machine.
For instance I may find that 0.93 work well for PLA on one machine. I might adjust up or down by 0.01 for a particular part but not that often.

Calibrating e-steps (extruder only) I think really depends on the machine. For something like a Flashforge Creator Pro or other type machines that are commercially made the e-step values are known and calculated so best to leave them alone.


On other machines calibrating the extruder e-steps is a good idea to get things to a known quantity then use the extrusion multiplier to fine tune.
wirlybird
Posts: 1374
Joined: Sun Jul 17, 2016 1:32 pm

Re: how common is it to change the extrusion multiplier?

grue19 wrote: Sun Jul 14, 2019 1:14 am well, i'm getting pretty decent 1st layers it seems and i did another one of those hollow cube prints with 2 .4mm walls and getting great width measurements with it. here's what i did. first started at extrusion multiplier of 1.10 and turned off my extruder esteps i had in the start gcode. then i printed that calibration cube and got wall width measurements of .91 - .92 ish. so based on calculation my new extrusion multiplier is .967 so i'll round that up to .97. anyway, the cube wall measurements are now .80 - .81. plus the height of that hollow cube is very nearly perfect 15.0mm. yeah, dpending on where i measure it ranges from 14.98mm to 15.12ish. but much better than before. also, i wonder if that could be due to mesh bed leveling - i changed my fade height in marlin from 10 to 20 to average out more at a finer gradation of height.

ok so my cube was great, now the first layer test i made .2mm high with .2mm layer and 1st layer of .2mm and % line width and % height both set at 100, the first layer test is pretty OK, it's like a piece of paper, all one piece and it measures in various places .20mm to .23mm so awesome!

i have only recently started playing with % 1st layer height and % 1st layer line width, but i also wondered about that - it shouldn't really be necessary and if it is, then the height really should only be the thing to change if you're doing say .12mm layers, but then the 1st layer height should be an even multiple of the actual printing height.

damn, i'm all excited now... it's working great and i don'thave to worry about esteps! i can just use that multiplier for extrusion!

thanks,
Don't forget to measure the filament diameter in several places over a few meters and enter the average into S3D. This is important or all your other work is for nothing.
grue19
Posts: 55
Joined: Sun Jun 30, 2019 12:06 pm

Re: how common is it to change the extrusion multiplier?

thanks. yikes a few meters! yeah, makes sense. i've done a few, well 2 feet ha!

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