SoliForum - 3D Printing Community — Nozzle diameter and free-air extrusion

Re: Nozzle diameter and free-air extrusion

2014-02-26T06:04:04Z

ggunners wrote:

Related question, when changing filament, what calibration steps are needed? Just extruder calibration and flow rate, or just flow rate?

I have always just calibrated flow rate. I dont see why extruder would be different per roll. Plus, flow rate will compensate if there was a difference.

Re: Nozzle diameter and free-air extrusion

2014-02-25T16:34:49Z

Related question, when changing filament, what calibration steps are needed? Just extruder calibration and flow rate, or just flow rate?

Re: Nozzle diameter and free-air extrusion

2014-02-25T16:10:37Z

Thanks! Upon further Googling, it also seems that is not very relevant when extruding *not* in free air (where hot filament immediately makes contact with other filament and it's shape is constrained).

Re: Nozzle diameter and free-air extrusion

2014-02-24T21:47:57Z

What elmoret said and linked to ... and yes it will be different between filaments based on their ingredient ratios and different based on the particular nozzle dimensions its shoved through and the speed you do that at ...

Re: Nozzle diameter and free-air extrusion

2014-02-24T15:54:56Z

Yes, it is normal.

http://en.wikipedia.org/wiki/Die_swell

Nozzle diameter and free-air extrusion

2014-02-24T15:28:41Z

Not sure why, but after swapping filament yesterday, I measured the diameter of the output. My micrometer said .535mm (with zero variation axially, and just 3 microns radially), very consistent. However, the nominal diameter of my nozzle is .4mm.

What am I missing? Is this expected? This was free-air extrusion @100mm/min with filament that is very close to it's nominal diameter of 1.75mm (grey Octave ABS). FWIW, my extrusion multiplier is .89 after calibration, which doesn't quite match either (.4/.535 = 0.75) -- this was manual extrusion, however, so multiplier is irrelevant.