I designed a standalone WiFi weight sensor for filament

Full write up with code and steps on how to put it together. If you know basic soldering it is super easy to put together. And the parts can all be bought for less than $7 in parts.

Write now I have it setup where one URL simply returns the weight left without any other HTML code. I was hoping to use that for OP to be able to pull the weight down. Maybe code some logic to pull that info live into the Filament Manager plugin. I might fork that one to do so. I don’t know any python though so I have no idea how well that will work.

Let me know what you guys think.


You may want to work with @OllisGit and his SpoolManager plugin...

Thanks. Looks like you’ve tagged him. He can chime in and see if he thinks it’s something that would work with his setup. I haven’t used that plugin yet.

Brilliant work.

I was working with someone who wanted me to spinup an automated IoT weighing project, did all the research and then the project just fell through the cracks. So I almost ended up building something like this within the warehouse space.

Ive worked with these ESP8266 devices so much the IOT part of it was fairly easy. It took me longer to measure and design the spool holder part of it. I probably should have just used the designs people had already made, but I didn’t want to wait for the bearings to come in the mail :slight_smile:

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Would we need to know the empty spool weight first? Some.manufacturers include that in the 1kg of filament you buy, so you don't really get 1kg of filament

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The empty spool weight is technically known as "tare" weight, for what it's worth.

Yes. You would need the empty spool weight. I coded a setting in there to account for that.

There is a site that has the weight of many common spools.

Let me know what you guys think.

Hmm. Also perfect to detect knots at the filament and... filament what is fixed at the spool.
If current VAL > shutdown Val = pause print.

That’s a good idea.

Hi @simpat1zq,
I like the idea very much and an integration to my spool-manager plugin should be easy to do (still in development, not released yet).

Do you think it is possible to detect also movement? Or better "no movement". That would be super-duper, because I am looking for a better run-out-sensor as my "microswitch" and "rotary-encoder" approach.
Maybe something like this:

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It should definitely be able to tell when the spool is being pulled. But not with any sort of accuracy. You won’t be able to tell how much filament was passed through from that measurement. But really, the printer/OctoPrint know better as to when the printer is using filament.

Edit. I guess I should have clicked the link. That should definitely be fairly easy to get readings from it using my project. With little to no changes to my code.

I don't think I'd necessarily start grafting on new functionality (like spool immobility) to a simple scale plugin. If it were me, I would just start a new plugin which does this given that the currently-printed plastic design could accommodate this.

@Ollisgit I'm fond of this approach to completely replace all filament-delivery problems. I've just been so busy with work that I haven't finished it yet.

Another approach could be to have bearings in the thing which holds the spool and to transfer the movement to a detector.