JASP - load cell spool holder

#1

ASP - Just another spool holder

But -this spool holder is special !

It has an load cell implemented :smiley:

The theory :

Load cell - an electronic device for measuring the weight of something. In this case the filament spool. You can calculate the leftover length of the filament if you know the weight and the specific density of the material.

The weight is proportional to the resistance of the load cell, its also proportional to the voltage, finally you got an value for calculation the leftover length of the filament on the spool. Of course we measure the spool and the printed parts too, but we can substitute it, because they are well known.

You can buy cheap load cells with A/D converters from eBay.
I recommend an load cell with max. 3kg for 1kg spools and a cell with max 5kg for the big 3kg spools. I bought an 2kg cell, its just at the end of the max. range !

OK, there is an display missing. I have some OLEDs in spare which I bought for some months.

The “rest” is an Atmega with some BASCOM coding :wink:

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Thomas

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#2

[B][color=#faf] that’s a neat idea, watch out though, spool weights vary, and not always the filament weight is absolute, can be 20 grams off at times!
neat idea though, keep us posted

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#3

No Problem,

the scale has an TARA-Button (red button). OK; maybe the spools (from the same brand) are a little bit different. If filament goes empty, the last few meters, it’s better to use your brain and doublecheck it there is enough filament left on the spool :wink:

Thomas

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#4

Totally love this idea, thx for experimenting with it

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#5

Print your own load cell spool holder ?

Thomas

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