Filament sensor alternatives

Hi, I am wondering for an alternative to this filament sensor [www.thingiverse.com], I understand that this one is a very cool little jig to have for your 3d printer at a premium price (in my place here)

What I have in mind is to rig a cheap digital caliper up to 2 decimal point in metric measurement and use the pinouts like this one [www.thingiverse.com].

A shorter one should be this one [www.ebay.com], I'm sure it has the same pinouts like any other digital caliper has.

I'm using mk8 extruder and my idea was to mount it somewhere in the mk8 itself or since the tire caliper has spring on its own, I was thinking to modify or rig the mount to be either printable custom mount, attached with bearing and hobbed bearing

Any of you guys ever thought of this solution? the pinout accepts 1.5v though

maybe this one is even simpler? [www.youmagine.com]

Quote
Frans@France
maybe this one is even simpler? [www.youmagine.com]

Nice

It's a good design, from Tom Sanladerer to be precise and 2 years ago too, but I don't know if he actually make a video about this idea of his, further more using magnet as sensor, What I had in mind is to use it directly on the extruder, it would sit close to the extruder motor since I'm going to use direct drive too.

I just thought of a very simple material that would use potentiometer instead. What I know is, arduino takes in voltage as value and turns it as a reading then if using potentiometer, it might be possible to do this too, another problem is might be the amount of force required to turn the potentiometer, might gonna need to have big dial to have fulcrum to turn it with lesser force. Or I would just use the linear potmeter instead

Edited 1 time(s). Last edit at 02/24/2016 01:44AM by sarf2k4.

But with a potentiometer you are not going to read the width of the filament and that is what both other designs are doing.

I got idea how to mount it and already printed it. But it gave me an off reading, before I soldered the wire onto it, it was ok and quite stable, but now it is not. I wonder if it was due to my poor soldering technique that destroyed the resistor film inside it?

Here is the pictures [share.pho.to]

Basically, the potmeter would sit next to the hinge's axis and there's a lever that is extended to connect it to the extruder clamp. In my case I'm using mk8 extruder here. I still need to improve the potmeter mount design as this one in the picture gave me a hard time putting on those screws back together again. The lever on the potmeter side has a tightener screw, that is for you to be able to 'calibrate' the vref returned from the potmeter. I have access to some filament that are well branded; zortrax, at 1.75mm too and I'm going to use that for my calibration to get 1.75v and then will read how much vref returned without any filament inside. Then that vref without filament inside will be the reference for calibrations during setting up the potmeter to this extruder

if it is a failed experiment or concept, then I'm okay with it, maybe can also have a similar idea like the low filament sensor mechanisms

Edited 1 time(s). Last edit at 02/25/2016 12:53AM by sarf2k4.

What exactly are you trying to achieve ?
Measure the filament diam ? What about oval filament ? In fact, the section area could be the same as the round one giving the same flow.
Detect filament absence ? A simple switch can do it. Mechanical or optical, plenty of simple solution there. The simpler, the lighter, the cheaper, the better.

Potentiometers used in servos are designed for and you better check their specifications in term of wiper and track life.
Regular pots used in audio are usually logarithmic, BTW and even the linear one unsuitable.