Monthly Archives: January 2013

PrintB.it

I have decided to branch out and create a new website with which I can provide more information regarding the designs I’ve made for my printer and also sell some parts that I’ve been able to source.

Come have a look : www.printb.it

PrintBit Logo 1sq

Extruder Calibration – [UPDATE]

Until recently I had not found a method of calibrating the amount of extrusion required for a good print which has worked well for me.

Well…. All that has change since I stumbled upon this post: HERE

Of course I calibrate the extruder stepper like most people do (see Slic3r is Nicer) but I still had to fudge around with the Filament Settings / Extrusion Multiplier and the Printer Settings / Advanced to get something that resembled a ‘nice’ print.

I would change the Advanced settings from their default, print something and then change again and again until the print looked right as I had never found a good guide for setting up Slic3r.

[UPDATE:

Since I’ve been using this technique for a few weeks I wish to share what extra bits I’ve learnt.

When Calibrating make sure you set the extruder to slow down when print time is below 0 sec.  I found it difficult to get a good calibration when the walls were made with a slow moving head so this makes sure the head DOES NOT slow down.

Set First Layer to 200% for good adhesion.

Set Infill to 125% to fill in any gaps in the top layer.]

So, from the “Solidoodle Tips” post I know that the Default Extrusion Width should be 1.4 times the layer height (eg. Layer height = 0.3 then Extrusion Width = 0.42) (0.2 = 0.28)

To then calibrate the extrusion:

  • Create or change your settings in Slic3r to use for this test:

Layer Settings: (click the picture for a larger version)

Layer Settings

Infill:

Infill

Advanced:

Advanced

Filament Settings: (obviously don’t copy my Diameter or temperature settings, just the Extrusion Multiplier)

Filament 1

  • Download / design a small (eg. 20 x 20 x 20mm or try this) cube.  Print with the settings as shown above.  We are trying to print a wall which is a single line of filament thick so minimum perimeters is set to 1 and Fill Density (infill) set to zero.  This will give us a single wall hollow cube.  Stop the print when it has printed halfway up the cube as we want to measure the thickness of the wall.
  • Measure actual printed wall thickness will digital callipers.
  • If you’ve printed at 0.3mm layer height this SHOULD read 0.42mm (the width you’ve told Slic3r to print).
  • If not (mine printed 0.55mm!!) then divide what it should be by what you’ve measured.  0.42 / 0.55 = 0.7636363636 for example
  • Copy and paste the total into the Extrusion Multiplier: (I rounded the number)

Filament 2

Print the cube again and re-measure.  If it’s still not quite right then divide the Extrusion Multiplier by the measured thickness, then times by what it should be.  (0.7636363636 / 0.44) * 0.42 = 0.72892561983471 for example.

I know this isn’t that straight forward but I wish I had found this method a long time ago!  Thanks go to Ian Johnson over at Solidoodle Tips, he’s got a great website there full of VERY useful information to help you with your prints.

Hope this helps, let me know if it does or if you’d like any further information. Thanks.