ABS Slicer settings for 1st layer

[Potatohead908]

So I am trying to dial in my new printer. I have the files for Materials and Quality that were linked to in the instructions. I've got my bed very square and set my Z height to Zero using a .051 mm (.002 in) feeler gauge.

I'm trying to really dial in the first layer right now. My problem is I seem to be going down a rabbit hole. I know I should only change one setting at a time. My questions are as follows:

1=In order to get the most accurate height of on a print I would think that my Z height should actually be set to true "0.000 mm". Am I wrong and if so will the .051 mm be an acceptable height?

2=What is the difference in the slicer settings for Print>Layers/Perameters>First Layer Height (in mm or %) and Print>Advanced>First Layer (in mm or %)?

3=Why would it give me the option of %?

4=Is my extruder nozzle .5 mm? If you where going to create a test cube would .5 mm walls be achievable? (I've tried and at first my walls were 1.05-1.1 mm thick, I changed my Extrusion factor to .8 and recieved a .8-.88 mm wall thickness). Now I cant get a first layer to lay down.

Also the overall dimensions of my cube were really close other than a height of 9.8-9.88 mm, when it was suppose to be 10mm.

Thank you for any input!

[IMBoring25]

1) For starters, .051 mm is .002 inches, not .02. With the other potential sources of error, you're not likely to ever see that. Z height is one of the things with which you can experiment to get print quality you like and a suitable amount of adhesion for your specific material on your specific print surface. If Z is set at true 0, it won't be very tolerant of overextrusion on the first layer and may sometimes have excessive bed adhesion, making parts difficult to remove (and it also won't be very tolerant of high spots on the bed).

2) You don't say if you're running this through MC (which I never have), but in native Slic3r, there's a box in the Advanced menu around several of the settings identifying them as Extrusion Widths. Beyond the obvious difference, First Layer Height, if expressed as a percentage, is computed against the default Layer Height, but First Layer Extrusion Width, if expressed as a percentage, is computed against the First Layer Height.

3) See answer to (2).

4) The standard Max v2 nozzle is indeed .5mm. If you leave the extrusion widths on automatic, they will by default be set wider than the nozzle. In order to extrude a suitable amount of plastic for a single-width wall you probably need to manually set the perimeters width to conform, and such a narrow extrudate probably would need a very accurate, true Z=0 to adhere.

Were you by chance using a .3mm layer height? 10mm is not evenly divisible by .3. Even if you were building a configuration at a layer height that came out even, +/- .2mm is +/- .007. That's a level of precision that even a precision machine shop would probably charge you extra to guarantee on most part features.

[Potatohead908]

IMB thank you for the input. I corrected my mistake on the .002".

-Also I was using a .1 mm layer height. I can see how this would compound by each layer. Didn't think of that.

-As for the Slic3r vs. MC....it was MC.

-I still don't get why you wouldn't use a true height of 0.00 mm for the Z0. If your first layer is .2 mm then that's what it should be. Not .2 mm with a little extra because I don't want it to stick too hard. I would think the slicer could factor this aspect in. Like the Extrusion factor for first layer. Again I'm new so may something just isn't sinking in.

-Also I maybe missing something because I don't recall seeing extrusion widths. Only extrusion nozzle diameter. I will have to look into this.

-If I were making a test cube I would probably be better served making it 1mm wide?

[Potatohead908]

Ok I found the default extrusion width is .06 mm.

[IMBoring25]

I think you misplaced some digits again. .06mm would be tough to achieve.

When I've done a test cube for extrusion width, I've made it a single nozzle width wall and manually set my perimeter widths to match in the slicer.

Here's the Advanced menu in a native copy of Slic3r. See the box around the first 8 settings?

Advanced Menu in Slic3r

[Potatohead908]

Crap! Yes I meant .6mm.

Thank you for the screenshot. What is the advantage to having a standalone Slic3

What is the difference between Slic3r, MatterSlice and CuraEngine? I'm probably going to start another thread asking this question.

[IMBoring25]

In my case, the advantage of running the slicer standalone is that it doesn't crash as much. I generally wasn't even getting MC to completely load before it crashed.

The slicers are different pieces of software. They're different, configured differently, and better at different things. I've never used anything but Slic3r, so I can't speak to specifics.

[Potatohead908]

Do you run your Printer via the stand alone or do you generate the code in the stand alone then paste it in the Terminal Window? I was having the issue with MC crashing too.

[IMBoring25]

I do usually run prints off SD but upload the gcode to the SD card and manually run the machines when needed through Repetier-host for the Rostock or through the web client interface for my Duet-equipped Mendel.

[Potatohead908]

Got it. I will look into Repetier Host. I'm not digging MC.

[Potatohead908]

IMBoring,

When I setup Repieter Host I'm just looking to set all the preferences like temp,speed, layer thickness and such. All the calibration and horizontal radius type settings are stored within the EEPROM correct? I think I'm going to try printing via RH tonight.

[IMBoring25]

Temp and speed are set in your slicer, which will generate the appropriate instructions in the gcode file.

Horizontal radius is in the EEPROM. It's a little more obnoxious to set in RH because you have to know the gcode, whereas MC has a nice dedicated GUI for such things.

http://reprap.org/wiki/G-code

M503 will output all the settings stored in EEPROM and their current values.

M206 is used to change values, with the syntax shown on the Wiki. My recollection is Horizontal Radius is type 3 and, being a float variable, it should be set with an X prefix. I don't remember the position number, but M503 will show you that, along with the correct type.

M500 saves your changes.

[Potatohead908]

So everything was set with MC. I take it I will have to reset everything if I move to RH...?

[Potatohead908]

Actually can't I just slice it with Slic3r and import the gCode to the MC GUI? I don't want to go through all the calibrating stuff again right now. I just want to print and play. I have it calibrated pretty damn nice now.

Also on a side note...can I use Slic3r and then save the gCode to an SD and just print from there? Or do I have to use the MC to create the gCode.

I've never printed from an SD card so I don't know what all is involved.

[IMBoring25]

EEPROM is EEPROM is EEPROM. If those settings are saved they'll be the same everywhere. Your Slic3r settings will only transfer over if you're pointing to the same configuration files.

Slicing in standalone Slic3r and using RH to put the resulting gcode file on the SD card is exactly what I do. Once the gcode is on the SD card you can launch the print from the LCD and don't even need a computer connected.

[Potatohead908]

Thanks IMBoring. You got me up and printing again. I started a new thread about what was happening with MC. It started printing a false line out of the blue on multiple STL's.

I'm able to use Slic3r and save the gCode to directly to an SD card.