Filament diammeter sensor

So ive decided to go ahead with figuring out how to make and implement Tomas Sandlanders InFidel filament diammeter sensor.

Im wondering if anyone else would be interested in a pcb or finished sensor. Im not looking to make much on this, but was thinking of getting enough parts for 5-10 sensors.

If your interested shoot me a message or comment here. Eta is still tbd, and im not looking for monies upfront, though the end cost will be just parts and shipping and maybe a beer if your feeling generous.

Im also curious if anyone here has built/used a filament diammeter sensor. If you have what are your thoughts/expierences with it.

If the cost isn’t too high I’m in. What do you estimate?

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Im still figruing out the components cost, but the pcb is like $3 each. Id guess under $10 and it can be sent out as regular mail.

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I was measuring some filament earlier I think I have a roll with wide variation but you have to be careful because it needs to be measure twice at 90° to get 2 dimensions that you average to get a real diameter. I think I want some of these too

Well ive ordered hardware, just need to figure how i want the pcb’s done. It might take me a bit but ill keep you posted on how things are going.

I think ill get parts for 10 units so that would cover 2 directions off thomas Sandlanders diammeter sensor. For those that are interested.

So its takken me longer than i want to admit, but due to the chip shortages a key part is on wicked backorder from what i can find, so ill be putting this on hiatus untill a future point.

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Can I ask how important it is to have a “Filament diameter sensor”? Also shouldn’t it be checking at least two dimensions?

I’ve had 3D printers for about 10 years now and I’ve never seen an issue with filament having diameter issues.

If anybody has any comments, I’d appreciate them.

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Good question. In all honesty there isnt really a need for a filament diammeter sensor anymore. The standards for fiament have come a long way from when 3d printing started that even the worst should be good enough. Im interested in it beacuse of when i found out that marlin supports it, why not try it. I still have a ways to go with my knowledge of 3d printing but i see it as a challenge. My end goal is to have it preform 2 maybe 3 functions. 1 being measuring the diammeter, 2 being a runout sensor and 3 having it identify a jam.

Im not expierenced in the finer things of circuitry so currently im leapfrogging on a design that can preform the basic function. There are other simmilar designs, but i like how compact this one was. The chip/parts not in stock i may actually have on hand, but i dont feel confident enough to solder connections that small yet.

You do have a good point to measure in 2 directions to get a good sense of even roundness. My plan is either to use 2, in series, or more likley just use a bearing with a u shaped external race. Its not as perfect as a laser measuring device, but i would like to test and compare it to a prusa roll i have thats unopened. If it measures simmilar then it serves its purpose. Im not expecting to see much of a varience, but the printer i want to install it on is ment for me to tinker with.

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Hey @Dr.Marvin , thanks for the share, Just found the same video (fell in the YouTube hole), pretty neet actually

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I was aware of the feature through marlin prior to the video, so its been one of my end goals with my modded printer. Get that going, and do a 10 minute benchy.

If i were to source the chips myself i could probably get everything, but through jlcpcb there were 2 or 3 components that just arent available at this time due to the chip shortage. Kinda kicking myself for not jumping on this before i fully realised what this chip shortage was going to get to.

What are your thoughts on useing it to make switching between 2.95mm and 1.75mm filamemt as simple as a bowden tube change? I realise there would be more to it than just that specifically, but i see it as a potential use for it since 1.75mm filament is now made to such a standard its not really needed anymore.

That’s a really cool idea. If it can be used that way then I’d totally be in for one!


It may be awhile before theres progress, but ill keep everyone updated if progress is made, and to what success.

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that would be awsome, The runout sensor would be pretty easy, Once contact on one bearing and one contact on the other and boom, your done

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