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Filament senors.

Posted by Dunston-UK 
Filament senors.
April 20, 2018 04:37PM
Hi

No doubt it’s been said before about sensors. Has there or is there a filament sensor that both detects runout and blockage? Had anyone got one who can share their experiences with them.

I have just recently changed from Titan to BMG and I am having blockages where the BMG eats through the filament at the same temps as the Titan would not. The Titan would just click away until intervention. I know it’s down to temp settings. I just wondered if a sensor is there that when you get a blockage it can call the pause print function.


Thanks
Re: Filament senors.
April 21, 2018 01:28AM
Wouldn't it be better to look for the cause of the problem, instead of adding another "band_aid"?
Re: Filament senors.
April 25, 2018 11:12AM
I've tried the Duet 3D mechanical filament sensor (uses a hobbed gear and a magnetic encoder) worked great until the assembly shifts and the magnet ends up slightly too far away from the encoder. But detects and monitors filament movement, so can detect runout and underfeed. Would work great if it had a metal housing.

They are working on a laser (mouse type sensor) version but so far I'm not sure where they are with it.

I have to say if someone could design a very reliable monitor I'd use one. When I was beta testing the sensor it caught 3 genuine problems (2 blocked nozzle) and one snagged reel. I managed to fix the snagged reel and resume, but had to dismantle the hotend for the blocked nozzles and couldnt resume.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Filament senors.
April 25, 2018 11:44AM
My Cubex Duo printer's extruders have two encoder discs, one on the pinch roller and the other on the motor shaft. The optical encoder wheels monitor blockage- if the motor shaft keeps turning and the pinch roller disc stops, the filament is blocked, either due to a jam or due to a tangle on the spool. There is a third optical sensor mounted at the input to the extruder that detects breakage/runout. Each extruder has a PCB with the optical sensors and a uC. If the breakage/runout sensor is triggered, you have to reverse the extruder to get the stub of filament out of the extruder/hot-end so you can feed in fresh filament.


Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]
Re: Filament senors.
April 25, 2018 01:36PM
Quote
DjDemonD
I've tried the Duet 3D mechanical filament sensor (uses a hobbed gear and a magnetic encoder) worked great until the assembly shifts and the magnet ends up slightly too far away from the encoder. But detects and monitors filament movement, so can detect runout and underfeed. Would work great if it had a metal housing.

They are working on a laser (mouse type sensor) version but so far I'm not sure where they are with it.

I have to say if someone could design a very reliable monitor I'd use one. When I was beta testing the sensor it caught 3 genuine problems (2 blocked nozzle) and one snagged reel. I managed to fix the snagged reel and resume, but had to dismantle the hotend for the blocked nozzles and couldnt resume.

We are still working on both sensors. The rotating magnet one is more accurate. The printed assemblies we used for the prototypes are not suitable for mass production, so we have teamed up with another company that has the experience we lack in manufacturing mechanical assemblies. The laser sensor is less accurate but still entirely adequate for detecting loss of filament motion, so we are having 100 manufactured to give interested users a chance to try them and tell us what they think.



Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Re: Filament senors.
May 07, 2018 05:37AM
Quote
dc42
We are still working on both sensors. The rotating magnet one is more accurate. The printed assemblies we used for the prototypes are not suitable for mass production, so we have teamed up with another company that has the experience we lack in manufacturing mechanical assemblies. The laser sensor is less accurate but still entirely adequate for detecting loss of filament motion, so we are having 100 manufactured to give interested users a chance to try them and tell us what they think.

Are any of these sensors still available to the interested community? I am new to Bowden setups and one of these could help me a lot...
Re: Filament senors.
May 07, 2018 07:05AM
They are not available yet, but we are having a small run of the laser one manufactured at present.



Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].
Re: Filament senors.
May 10, 2018 08:47AM
Quote
DjDemonD
They are working on a laser (mouse type sensor) version but so far I'm not sure where they are with it.

Prusa i3 MK3 has an optical sensor on it, and from what I can tell it seems to be able to do both runout and blockage detection. I'm not quite sure about the exact function, as I can't find the spec sheet, but it's supposed to be open source so I'm hoping they come out with the individual component on its own, or at least the design so someone else can.
Re: Filament senors.
May 10, 2018 03:43PM
Quote
dc42
They are not available yet, but we are having a small run of the laser one manufactured at present.

Faster! spinning smiley sticking its tongue out I've had two large prints fail due to a knot on the spool and a few where excessive retractions caused the drive gear to eat a notch in the filament. Would be super excited to get some of those ordered up for my printers when they get released.

What's the ETA for the sensors? End of summer? smiling bouncing smiley

Edited 1 time(s). Last edit at 05/10/2018 04:07PM by jerryjs8.


Build Log - DDDE 330x330x300mm Ultimaker
Re: Filament senors.
May 10, 2018 09:42PM
It's probably a bit much, but I'd really like a sensor that detects jams and filament diameter and adjusts the flow rate accordingly.
Re: Filament senors.
May 11, 2018 09:44AM
No one has cracked this yet as filament isn't necessarily round. You'd need a sensor that can detect cross sectional area and movement.

Edited 1 time(s). Last edit at 05/11/2018 09:45AM by DjDemonD.


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Filament senors.
May 12, 2018 01:01AM
Speaking of asking for the impossible, it also need void detection.... for those wonderful filaments that have air bubbles
Re: Filament senors.
May 12, 2018 02:47PM
Quote
DjDemonD
No one has cracked this yet as filament isn't necessarily round. You'd need a sensor that can detect cross sectional area and movement.

I think two sets of caliper like sensors measuring in opposite directions would give a good enough estimate of the volume of the filament to accomplish this. I'm not an electrical engineer, so I don't know if those type of sensors are available for integration, or what they cost.

Edited 1 time(s). Last edit at 05/12/2018 02:47PM by Pheneeny.
Re: Filament senors.
May 13, 2018 07:39AM
I discussed a method briefly in this thread [forums.reprap.org]
It does work but I didn't continue with the exploration as I have other things to do. Anybody (except patent trolls) are welcome to see if they can make something of this. There may be things like temperature and barometric dependency but how important and whether they can be compensated for is unknown. It has to be better and cheaper than using two digital read outs though.

Mike
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