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stoofer
(@stoofer)
Estimable Member
Filament sensor idea

I got to wondering (after de-activating my filament sensor again due to false errors on my shiny black filament)...

Would the filament sensor be better positioned to read immediately after the filament passes through the bondtech gears rather than before?

My logic is this: the gears cut grooves into the filament. These grooves would, I suspect, be easily readable by the sensor as motion as they pass infront of the sensor.

There are obvious package hindrances to trying this, but food for thought?

A test for this could be to mount some gears on top of the current extruder assembly - there to do nothing other than mark the filament as it's drawn into the machine.

Opublikowany : 03/04/2018 7:04 pm
mark.l26
(@mark-l26)
Active Member
Re: Filament sensor idea

I made the same suggestion in another thread a while back. Yes placing he sensor after the gears should fix the problem... not really a solution for the current design, but something that can happen on the next revision to the design.

Opublikowany : 03/04/2018 7:25 pm
Kwaad2
(@kwaad2)
Honorable Member
Re: Filament sensor idea

It may be able to check the filament better, but it would be impossible to detect if you are out of filament and once it gets past the bondtech gears there will be no way to extract the filament that would be left in it.

You also couldn't use it for auto loading filament.

Actually, none of the working features, would work at all.
😯

Edit: some kind of marking apparatus may work, mounted above the filament sensor, may work, but would be problematic for loading/unloading.

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Opublikowany : 03/04/2018 7:29 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Filament sensor idea

Also you would have less constraint of filament
Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Opublikowany : 03/04/2018 7:37 pm
stoofer
(@stoofer)
Estimable Member
Topic starter answered:
Re: Filament sensor idea


It may be able to check the filament better, but it would be impossible to detect if you are out of filament and once it gets past the bondtech gears there will be no way to extract the filament that would be left in it.

You also couldn't use it for auto loading filament.

Actually, none of the working features, would work at all.
😯

Edit: some kind of marking apparatus may work, mounted above the filament sensor, may work, but would be problematic for loading/unloading.

True. Working just as well as when I turn it off isn't much of an improvement...

There might be legs to the marking apparatus. If I can find some filament with a really really high failure rate on the sensor, I could just run a length gently through the Titan Aero on my Kossel to test the principle.

Opublikowany : 03/04/2018 9:09 pm
mark.l26
(@mark-l26)
Active Member
Re: Filament sensor idea


It may be able to check the filament better, but it would be impossible to detect if you are out of filament and once it gets past the bondtech gears there will be no way to extract the filament that would be left in it.

You also couldn't use it for auto loading filament.

Actually, none of the working features, would work at all.
😯

Edit: some kind of marking apparatus may work, mounted above the filament sensor, may work, but would be problematic for loading/unloading.

Well none of them work anyway, when you have to turn the sensor off!

Your points are valid though...The "lost" functions can be achieved with a 2nd sensor, simple (low cost) beam-break sensor placed above the gears could provide the load and out of filament sensing.

I also agree that some form of marking mechanism, like a 2nd set of passive gears, could also work.

Opublikowany : 04/04/2018 12:02 am
moggieuk
(@moggieuk)
Eminent Member
Re: Filament sensor idea

Or an easy to replace mechanical sensor.... 🙄 I’m not seeing the benefit to the optical one.

Opublikowany : 04/04/2018 3:05 am
raspeitia
(@raspeitia)
Eminent Member
Re: Filament sensor idea

If the filament sensor is optical, would it benefit to have a checkered black, white, gray sticker behind the filament to provide contrast for the sensor?

Maybe some sort of optically reflective material like a projector screen that has a micro reflective surface?

Opublikowany : 04/04/2018 3:11 am
stoofer
(@stoofer)
Estimable Member
Topic starter answered:
Re: Filament sensor idea


Or an easy to replace mechanical sensor.... 🙄 I’m not seeing the benefit to the optical one.

The optical one (if reliable) could provide more functionality. Having to turn it off to avoid annoying printer stoppages sort of defeats the whole point, though.

I'm hoping to have a test rig built this weekend. I have a spare bondtech, and it wont be too hard to make something that sits on the extruder housing and clamps to the existing input thingy/cover that loosely holds the gears together enough to mark the filament on it's way through...

I have some clear and translucent green filament so I hope I can find between those a material with a really poor MTBF to test this on.

Opublikowany : 05/04/2018 1:07 am
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