How do you accurately measure your filament diameter?

Hi,

I was wondering how you guys measure the diameter of your filament using callipers? Say I want to measure the diameter at different points along a meter of filament from one of those smaller spools. On these spools the filament has quite a lot of curve to it. This makes it hard to get it straight between the callipers. I therefore really have to pinch them to get a measurement. But because I have to use a lot of force I'm wondering if the measurement is still accurate enough because it differs a lot from a more "loose" measurement off course. Very curious about how you do this right.

Regards,

Nilez

Edited 1 time(s). Last edit at 02/17/2014 12:39PM by Nilez.

If the spool is held in some sort of holder mechanism, measure the diameter just as the filament comes off the spool. Move some more and measure again etc.

Measure in the direction towards the spool walls then you will not have to cope with filament curvature.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

Thanks Neil,

So measuring in both directions isn't really necessary? I was a bit worried that the filament is a bit oval because I'm getting different readings from "both directions" and need to average the result. But the difference might be caused by the curvature.

I have not seen oval filament (yet) but I do average several readings. You can only do your best!

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

In the directions in line with the sides of the spool, the readings are always fairly consistent but it's a nightmare in the other direction. So from now on I'll just take the manufacturers word for it and assume the filament is nice and round

Edited 2 time(s). Last edit at 02/17/2014 12:41PM by Nilez.

The first ABS I had was very oval. When I switched to a new reel that was round I got a noticeable increase in quality. I think the oval stuff feeds at a variable rate depending on its orientation in the pinch wheel.

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[www.hydraraptor.blogspot.com]

Was thinking that perhaps there is a wire gauge (digital) could be used.

I found this link [waltergordy.blogspot.co.uk] to be very helpful however its only a concept, still doable by today's standard.

When I measure my filament once it has been extruded in mid-air, it measures .63 to .65. Is that ok?

It is normal for ABS, PLA tends to come out smaller. Die swell depends on viscosity and flow rate. When building an object it gets stretched to the cross section defined by flowrate over feedrate regardless.

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[www.hydraraptor.blogspot.com]