As Marlin is now supporting realtime filament diameter sensing and compensation,

This interfaces a micrometre with Arduino

Great work tom. Definitely interested in helping how I can if you need another tester

@paul_wallich WRT measurement time, my concern was that if filament is feeding through it, as the measurement is taken, bends in the filament might cause a bad reading the filament is moving lengthwise at a significant fraction of the speed that the scanner moves across it.

I wonder if, while you’re in there, putting in an rotary encoder on an idler might be a good idea? Just knowing the filament has stalled would be a good thing, and if you can accurately measure how far the filament has moved, you’ve moved from a stepper motor to a proper servo.

@Richard_Betel baby steps. Let’s first do this part right, then focus on the next big thing.
I’ve seen too many projects fails because the maker gave in to feature creep - let’s just add this little thing and that feauture while we’re at it, and in the end it turned into an unmanageable monstrosity.

@Whosa_whatsis
Ah. You’d probably need to guarantee less than a millimeter of travel during measurement, which would mean somewhere in the low tens of milliseconds for the measurement. Wouldn’t want something oscillating that fast all the time anyway.

But I did just realize that those polygonal rotating mirrors must be available surplus.

I’m in for testing, can assemble it / program an attiny if needed.

Hi! I’m in as well. My thoughts about this are:

  • optical measurements: possible smaller and lighter package overall
  • mechanical (bearings) measurement: maybe more simple to get better/more accurate results

Furthermore an additional approach:
How about throwing a laserline across the filament (like the optical method) but then look at it from an angle? Like this you don’t see a straight line anymore, but an “arc-like” line, representing the surfacce-form of the filament (at least one half of it).
Or does this go way to deep into extremely difficult to implement? Hmm…

Hello! I’m working on a filament width sensor based on ATTiny85 and TSL1401CL. See http://www.thingiverse.com/thing:699308 for details

Hello. I would love to help testing and reporting feedback. Not development, i don’t understand about that. Cheers o/

Tom, I’ve made your filament width sensor work with the “Mackerel” firmware. It does not require any mod to the Mackerel/Marlin Firmware. I just made some adjustments to the code you provided for the attiny and added some pasive components, if you are interested let me know so I can send you the code and schematic.

@Mario_Munoz awesome! Feel free to publish the mods yourself on Youmagine or Thingiverse - this isn’t about me or my design, this is about the community getting another (hopefully useful) tool.