mdavis1863 wrote: ↑
Tue Jul 03, 2018 11:32 am
I am still not understanding if there is any difference between Extrusion Multiplier and Extrusion Width for the case of single-wall printing. The above answer only deals with multiple lines. But if I am printing a single wall, then is there any difference between decreasing Extrusion Multiplier by 10% versus decreasing Extrusion Width by 10%? I have printed some test blocks, and at first glance, they both seem to decrease the overall weight and thickness by about 10% (approximately....I have written down data but not analyzed yet). Also, I am still in the process of testing strength.
The way I think about this and I have never used any other slicer is as follows.
Extrusion width is how wide your line of plastic will be laid down on the plate. There is auto set which uses a mathematical formula rule of thumb to set the width or you can choose a width slightly smaller than that rule of thumb. I will use my M2 manufactures profile default for a .35 nozzle which is .4 as the example.
So a single wall square will measure .4mm thick.. IF
your extrusion multiplier is correct! Too much plastic and the wall is too thick too little and you get gaps. Set correctly you get very frew gap and accurate sized parts.
This is how I set Extrusion Multiplier accurately but is NOT applicable for All print so experiment at your own risk!
So I print a single walled square and use an accurate digital micrometer to measure the wall thinness. It should be the exact +-.002 my extrusion width. Too fat lower Extrusion multiplier too thin raise, reprint repeat until it is correct.
The other thing that can be set "exactly" with this same square is your starting height. If your single wall model is 2mm tall and you are printing at a layer height of .2, then your square should be 10 layers tall and measure 2 mm +-.002 tall.
Examine the square with a jewelers loop, layers should be the same bottom to top. If starting height too close it will be less than 2mm and bottom layers will be kicked out. If to high, it will be taller than 2mm and layers could be de-laminating
Setting starting height is probably printer specific but will explain how I do it on the Makergear M2 as the gcode part may be applicable depending on firmware I would guess.
I heat the nozzle, remove the filament and wipe off the nozzle while hot so it is clean then turn off the heat
Once cool, send the printer the following gcode from the terminal
G28 ;; which homes the printer
G1 F1000 X100 Y125 Z0 ;; send it to starting height center of bed
This put my M2 at starting height center of plate . Adjust X and Y location for you particular printer build size to get you in the center
Measure clearance with the feeler guage, should have some drag (I use a .127mm )
If no drag or too tight , I loosen lock nut and physically adjust extruder height (M2 RevE V4 hotend)
Once physically set I print the single walled square and measure it.
It should be 2mm +- .002 if you got it prefect with the feeler guage. If not continue.
To fine tune it, send the printer M503 on the terminal
Look at the output line starting with 206 i.e. Recv: echo: M206 X0.00 Y0.00 Z10.54
For the M2 the Z part is the firmware offset and what you would think of as the starting height of 0. The bigger the number the closer to the bed the smaller the number the father away which is not intuitive (your firmware may be different)
Using the above example of Z10.54 , if your square measure 2.04 then your are too high or far from the bed
making the Z number larger moves the bed and nozzle closer so you would send M206 Z10.58
then M500 to save the setting.
If the square was 1.96 then it is too close so make the nubmer .04 smaller and send M206 Z10.50 followed by M500 to save
Reprint and repeat if needed
I know this is not what this thread is about but when these 2 items are not set correctly it causes lots of other issues Hopefully this will help someone.