Prusa I3 from Maker Farm

I have a Prusa I3 from MakerFarm.

The problem I'm having is when I print narrow vertical prints like case edges it lays down three lines One on one side one on the other and a smaller one down the middle. The problem is that middle one isn't enough to fill it completely. so the edge ends up partially hollow and brittle. I don't know what I'm doing wrong. I don't know what setting to change.

I'm using a magma head with 3 mm ABS filament. I have no idea what setting to change to fix this. Otherwise it's perfect.

Please help, please.

Z

The printer is probably doing fine. It's a design for manufacture issue.

The printer can only lay down fixed width strips of plastic. That's all the software / firmware / hardware knows about. If you have a 0.4 mm nozzle, you can set it up for something in the 0.4 to 0.5 mm width range. Let's say it's 0.4 mm.

If you ask the printer to do a wall that's 0.4 mm wide it lays down one strip. If you ask for 0.8 mm wide it lays down two. If you ask for 1.2 mm it lays down three. Everything works fine / looks fine.

If you ask for a wall that's 0.5 mm, it can't do it. I puts down a 0.4 mm wall. If you ask for a 1.0 mm wall, it puts down two 0.4 mm tracks and a 0.2 mm gap. If you ask for a 1.5 mm wall it will put down 3 tracks and only fill 1.2 mm.

The wall thickness on the part needs to be designed to match the printer. That's something you do with a CAD program before you generate the stl file that feeds into Slic3r. If you only have one wall, and you know exactly what it is, you might be able to manipulate your layer height and extrusion width to fill things better. That's generally not an easy thing to do.

Just go to different slicer... Cura or Kisslicer. Kisslicer does a great job on making lines overlap.

I've tried Slic3r, Cura and Kiss. They all have a similar issue with thin features.

You should also go to the calibration wiki, and look for the fine tuning of the esteps.

Another possibility is to increase flow a bit.

Another possibility is that your filament is not exactly 3mm, you need to measure it in 3 places, average it out, and then use that in your settings.

Are you using 100% infill?

If the printer is perfectly calibrated and you try to print a straight wall (or feature) that's down in the range of your extrusion width, you will have issues. The slicer can not / will not / should not vary the extrusion width in a dynamic fashion. I's not smart enough to do that properly.

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uncle_bob
I've tried Slic3r, Cura and Kiss. They all have a similar issue with thin features.

I use kisslicer 1.1.0.14 and it fills up even smallest hardly visible gaps between lines. Yes, that can be a problem sometimes because it over extrudes BUT it never leaves a gap between lines... Thats my exprience with this exact version of kisslicer.

BTW, I have a part printed by UP!mini printer (using their stock software i suppose) and it has a gap between walls. And I have printed same part using kisslicer for multiple times and it always makes solid walls. Layer height or thickness does not matter.

If it does a variable extrude without you optimizing it, it will create far more problems than it solves. Print speed and layer height also relate to extrusion width. There's no way it can guess at how to modify them.

Edited 1 time(s). Last edit at 12/17/2013 08:52PM by uncle_bob.

Thanks so much for all the answers...

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uncle_bob
The printer is probably doing fine. It's a design for manufacture issue.

The printer can only lay down fixed width strips of plastic. That's all the software / firmware / hardware knows about. If you have a 0.4 mm nozzle, you can set it up for something in the 0.4 to 0.5 mm width range. Let's say it's 0.4 mm.

If you ask the printer to do a wall that's 0.4 mm wide it lays down one strip. If you ask for 0.8 mm wide it lays down two. If you ask for 1.2 mm it lays down three. Everything works fine / looks fine.

If you ask for a wall that's 0.5 mm, it can't do it. I puts down a 0.4 mm wall. If you ask for a 1.0 mm wall, it puts down two 0.4 mm tracks and a 0.2 mm gap. If you ask for a 1.5 mm wall it will put down 3 tracks and only fill 1.2 mm.

The wall thickness on the part needs to be designed to match the printer. That's something you do with a CAD program before you generate the stl file that feeds into Slic3r. If you only have one wall, and you know exactly what it is, you might be able to manipulate your layer height and extrusion width to fill things better. That's generally not an easy thing to do.

This make sense, however, it does try to lay down a middle track, it just runs the extruder a lot slower so I end up with a smaller track laid down. I would think if it would run just a little faster there wouldn't be a problem.

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Edvardas
Just go to different slicer... Cura or Kisslicer. Kisslicer does a great job on making lines overlap.

I decided to try Kisslicer, the problem is I'm a complete noob and can't figure out the settings. When I went with what I thought they should be, the extruder didn't even turn! HELP!

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Antslake
You should also go to the calibration wiki, and look for the fine tuning of the esteps.

Another possibility is to increase flow a bit.

Another possibility is that your filament is not exactly 3mm, you need to measure it in 3 places, average it out, and then use that in your settings.

Are you using 100% infill?

I went through the wiki and fine tuned the extruder steps like it suggested. Didn't make much difference. I can not figure out how to increase the flow in slicer. Noob here. Sigh. I measured my filament and it looks to be exactly 3mm. Also no matter how many times I try to print the failure is in the same place. I would think if this was the issue the failure would be random. I'm not using 100% infill because there are large areas that I use Honeycomb on. Maybe as a test I will try 100% though.

Right now if someone can give me some guidence on how to set the stettings in Kisslicer for me to test, it would be GREAT. I have no idea what most the settings are for, I don't see a setting for the heat bed and I'm having trouble getting the extruder to even turn.

Zenock under Printer-Firmware choose different fimware. I had to choose "5D-Absolute E"

Uncle Bob, it is not really variable. Thing is that if there is 0.2mm gap between lines it will just lay down a chosen value (in this case 0.5mm) width in its place. Thats not perfect but I can not really trace any big negatives in that.

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Edvardas
Zenock under Printer-Firmware choose different fimware. I had to choose "5D-Absolute E"...

Thank you... I will give that a try.

In Slic3r I usually start at 90 degrees for the heating bed on the first layer and move up toward 110 degrees for subsequent layers. Any way to do that?

When I Zero my machine the nozzle sits exactly on the heating bed (Glass)... in slic3r I have specified to start printing at .3mm so it raises to .3 before it begins printing. Any way to do that?

Any help here would be greatly appreciated.

Z

1. There is only one temperature for bed I am affraid. You can change it manually in pronterface while printing. Or type it directly into gcode after a first layer, I suppose. Have not done that myself.

2. Under Printer- hardware there is bed rougness function. I guess you should increase it so you start to print higher.
However, I start my print at paper thin gap. Gives really good adhesion.

Another thing is that kisslicer does not need to know your nozzle diameter. I found this to give impressive results as extrussion is much more precise.
Also, every guide on net tells that your line width should be equal or more than your nozzle diameter. Kisslicer does not work well with layer width set to nozzle diameter. I use 0.5mm nozzle and have set my line width to 0.55mm for both 0.2 and 0.3 layer height. This and 15mm/s perimeter speed gives impresive surface quality.

Edited 1 time(s). Last edit at 12/18/2013 05:25PM by Edvardas.

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Edvardas
1. There is only one temperature for bed I am affraid. You can change it manually in pronterface while printing. Or type it directly into gcode after a first layer, I suppose. Have not done that myself.

2. Under Printer- hardware there is bed rougness function. I guess you should increase it so you start to print higher.
However, I start my print at paper thin gap. Gives really good adhesion.

Another thing is that kisslicer does not need to know your nozzle diameter. I found this to give impressive results as extrussion is much more precise.
Also, every guide on net tells that your line width should be equal or more than your nozzle diameter. Kisslicer does not work well with layer width set to nozzle diameter. I use 0.5mm nozzle and have set my line width to 0.55mm for both 0.2 and 0.3 layer height. This and 15mm/s perimeter speed gives impresive surface quality.

I've never printed from pronterface as that I just save the gcode to a memory card and print straight from the card. I will see if I can figure out the gcode well enough to have any idea where to put it. If I set the nozzle temp different and look for where that changes, maybe that will give me a good idea where to put the bed change? Though I'm not sure what the code for bed temp is. Here's hoping I can figure it out. :-)

I have not tried this, but...
Under "prt g-code" choose "n(*) layers". On the left type in 2. This means that you are choosing layer number two to change code. On the big screen type in "M140 S110". M140 should mean a setting for bed temperature. S110 is temperature. S100 would be 100 degrees Celsius and so on. Should work. I would suggest closing kisslicer after typing in this code. Open again and then slice your model (code might not work otherwise on your first sliced model).
If you have LED on your bed you can see if this works. If LED does not turn off even for a few seconds in a few minutes then everything is working great.

BTW, why would you want to increase temperature after first layer? Everything I have red tells to decrease it once printing is in 2nd layer.

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Edvardas


Uncle Bob, it is not really variable. Thing is that if there is 0.2mm gap between lines it will just lay down a chosen value (in this case 0.5mm) width in its place. Thats not perfect but I can not really trace any big negatives in that.

Ok, but then it's not actually doing what you asked it to do (print a wall this thick). It's decided to re-design the part with a thinner wall. That approach has it's problems as well. The inside of the print is fused, but potentially the outside has bumps in it where it decided to jog down one layer (think of a wall where the inner and outer surfaces are curves with different a different radius as an example).

Edited 1 time(s). Last edit at 12/18/2013 09:21PM by uncle_bob.

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Edvardas

BTW, why would you want to increase temperature after first layer? Everything I have red tells to decrease it once printing is in 2nd layer.

Laugh... because Collin a maker farm told me to. Serious no other reason than that. I'm a total noob at this stuff so when I don't understand something, I just do as I'm told. ;-) Anyway, thanks for your advise.

All of the default settings on the MakerFarm stuff have you printing the first layer hotter than the later layers....

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uncle_bob
All of the default settings on the MakerFarm stuff have you printing the first layer hotter than the later layers....

That is simply not true Bob. I bought mine from MakerFarm and use the defaults. First layer the heat bed is at 90 degrees subsequent layers 110 degrees.

You can go here... [docs.google.com] and download the config file. This is the same one he points to from his build instructions...

Line 4 sets bed_temperature = 110
Line 34 sets first_layer_bed_temperature = 90

The hotend stays at 225 for the entire print.

Note this is the default configuration he provides for the magma hot end so I don't know what the other config files are set at. However, I picked my printer up from Collin in his home and while I was there talking to him, he told me to print the first layer at 90 and subsequent layers at 110. So there is that too.

He may have provided a reason for doing this, but I don't recall what it was.

Z