Hi Everyone.
Overview
Last week I bought Simplify3D. A colleague of mine told me its the best slicer he ever had, doing very good support structures that are easily removable. So I thouht: Lets give it a try.
I decided to use a simple object like a 2cm cube to compare results with the slice done by Luban. In my opinion Luban is dooing a very good job its very well optimized for the snapmaker and common fillament.
Next you can see (starting from the left) the cube done with luban, the same cube done with S3D and settings provided by brent113 (but removed the backlash settings for now). Because I had some major issues I reduced the high for the next tests and after houres of testing and investigation of g-codes I got a a comparable good result.
Both cubes are good dimensioned in all directions (dindt meseared it, only compared by rotating 
)
Next picture is showing a direct comparison of the 2 cubes. (left Luban, right S3D).
As you can see, I got a good cube just with the basic setting of Luban (PLA, FAST).
The resulting cube with the basic S3D settings was not so good. You can see problems with the under extrusion and to few overlapping of infill and walls. The gab between inner and outer wall is not only a problem of under extrusion, as I found out later.
I lowerd the high to 7mm to get a faster result. The left one shows the next step with increased extrusion and more overlapping and on the right is my âfinal prototypeâ with the best results for now.
Details of the S3D settings
Let me explain my settings and why I chose them in that way. The order is slightly based on the order I have done them step by step.
Speed
Other than in Luban S3D often uses a base value (here âdefault printing speedâ) and other values are only given in relation to that value. So for my âFastâ settings I chose the same speed as in Luban (3600 mm/min; Luban is using mm/s!) then I calculated the percentages for the outline and the infill underspeed. Unfortunatly S3D has no seperate setting for the inner walls, it uses the infill speed for them. X/Y and Z movement wasnt changed now maybe Z movement could also be higher (I think 1800 is used by luban). There is another speed setting for the first layer in the âLayerâ tab (see below).
Layer
For âFastâ priting I chose the same settings like in Luban. So I chose 0,2400 for the layer high and I think this is the maximum you can get out of a 0,4 nozzle without bigger quality problems.
3 Layers for top, bottom and walls is good start for now and also what Luban does. Outline direction Inside-Out. A layer is allways started with the most inner wall -> outer wall -> infill.
I allways use a first layer high of 0,200mm independet from the quality setting because this is best working for my calibration behavior. With 40% speed you get 1440 mm/min for a good stickiness of the first layer. The speed setting for firt layer is not applied to the âAdditionsâ (Skirt).
The fact that the first layer settings can only be configured in relation to normal speed and normal layer high is also the reason why the auto-config quality settings are not working for me (the percentages are not part of the quality settings). I also changed the starting point settings. That has something to do with my prefered start script. I will explain this later.
Additions
I prefer to allways have a skirt. To get a good starting extrusion and maybe a better adhesion. I increased the skirt lines for a test from 3 to 4 because I had a strange behavior but later found out it has to do with the retraction (If you set retraction it is done between every skirt line but this can be influenced: See âAdvancedâ and âExtruderâ
Other
I dindât thought about or changed the briding settings. The fillament settings are adapted to my used fillament (I dont know the density so this is unchanged). Changes in diameter and density should lead to a change in amount of extrusion but you should use the setings under âExtruderâ tab to correct under/over extrusion.
Extruder
The nozzle diameter of the SM2 is 0,40mm. Thats a fact! The first printing result show that by default (multiplier = 0,90; Extrusion Width = Auto) the inner and outer walls seem to be not connected. This is not only because of an under extrusion but also because the âAutoâ setting is leading to an bigger offset of the printed lines (0,48mm). I realy cant understand why S3D is chosing a value so much bigger then the nozzle diameter. If extrusion and speed is at an optimum the diameter of the resulting line could not be bigger then the nozzle diameter (at least not so much bigger) it would need a massiv over extrusion. Physics says that by cooling something it will shrink⊠OK by principle the fillament should not shrink to much but it does at least very very little. So you should definitly set the Extrusion Width to Manual = 0,40mm and (if you ever have) compensate an over extrusion by thee multiplier.
Regarding a retraction. Maybe it can be turned off completely but I feel better to have one when the printing head travels over the field. I prefer not to retract the fillament (Distance = 0) but only lift the head. Some times a fillament retraction is not compensated correctly so it leads to a bit of missing fillament at the next printed line (maybe this can be corrected by backlash compensation but for me its easier to simply not do it).
Advanced
I dindt changed to much here. Only set âOoze Controlâ to âMinimum travel for retraction = 3mmâ. The value can even be smaler but I set this to stop S3D doing a retraction between every skirt line (it only needs to travel 0,4mm so why does it retract at all?)
Infill
Here I changed the fill pattern to a full honeycomb to get a faster filling but I increased the filling percentage to 20% (its the same setting as the slider with hidden advanced settings).
An important change is setting the âOutline Overlapâ to 55% ( It was set to 20% by default I think). I verified this value by looking into the g-code Luban produces. This will perfectly close the gaps between infill and inner wall.
Temperature
The extruder temp is dempenting on yout used fillament. The white one I used here is best printed with 205°C.
My default heating bed temps are 70°C (just set it to 71°C to test if the SM2 realy show me the value I have set here) for the first layer an 50°C for the rest of the print.
Cooling
I missed a screenshot here but I dinât change it.
Support
I also dont have a picture here but evrything was truned off here. A simple cube does not need a supprting structure .
G-Code
I only changed the dimension of the build volume here.
Starting Script
I modified brent113 starting code to get a behavior thats like Luban does. I like starting in the lower left corner to extrude some filament off the printing bed and then wiping it at the corner. Thanks @brent113 for showing how to use the variables for the temp settings here I would have searched forever maybe.
End Script
I changed to code here also a bit. Just as I re-read I am not sure about the M107 and what fan it turns off⊠have to check this again. The rest turns off the heatings retracts some fillament and the head. Finaly its moves the head to the home to get good access to the printed object.
Final words
So thats it for now. With this settings I got pretty good results for fast printing, comparable with the results of Luban. All in all I have to state that Luban does a very good job and at the moment I donât see a reason (for myself) to do everything with S3D. I will definitly try slicing some parts that need supports to compare this results as well.
For printing I imported the g-code to Luban and used WiFi upload. I dinât tried to a direct connection.
I also had general issues with S3D getting it to run. In the first days I had permanent freezing issues that where caused by the NVidia driver and some strange overlay setting. I needed to do a manual update of the driver and disable some background services. Donât know what exactly finaly did the trick.
Thanks for reading,
Thomas
PS: Use the FFF file on your own risk. It may contain mistakes.
A350_my.fff (12.6 KB)
