How to fix the IR Filament Sensor?  

RE: How to fix the IR Filament Sensor?

@marino

I had this mod for a while and it would not work consistently. This has very tight tolerances. Eventually switched to

https://www.prusaprinters.org/de/prints/7690-tzb-mk3smk25smmu2s-extruder-mmu2s-no-tower-v2

and it just works.

RE: How to fix the IR Filament Sensor?

@shilbert

Thanks for your suggestion. At the beginning I visited the page you mention in your post.  It looked very interesting but the mention about special TZB firmware stopped me although later I realized it is not necessary.

RE: How to fix the IR Filament Sensor?

@marino

Exactly. I used it for a while. It did not make things better or worse for me. I believe most issues boil down to

a) the filament sensor being flaky (on/off) when the filament travels through the gears

b) the filament path not being optimal especially for TPU.

All I can say is that problems disappeared when I put this on. The very adventorous might want to look at https://mihaidesigns.com/pitstop

RE: How to fix the IR Filament Sensor?

@marino

i appreciate the offer, but we should not have to engineer a solution for a product being sold by a corporation, that should be far more useful than it is.

RE: How to fix the IR Filament Sensor?

MMU2S has been criticized enough. The open approach makes it possible to make it work in the first place. 

Prusa has a history of making their products netter over time. Other companies make the products obsolete and make you buy new ones. 

I guess they even have a return policy.

Not ideal but far from a major hurdle in life.

RE: How to fix the IR Filament Sensor?

didn't say it was a major hurdle, just that it should be a reliable and functional product, not requiring significant time investment to get it work correctly, i will likely hold on to it whenever they update the product (if ever). Or maybe use the steppers for a truly mini prusa 🙂

RE: How to fix the IR Filament Sensor?

Prusa is an excellent company. I bought its products as kits on purpose, to be able to know exactly how the different parts work, why they are necessary and appreciate/evaluate their design.

As far as the chimney issue is concerned it is possible as well that the manufacturer/s of IR PCB, that I presume is not Prusa, supplied items with small different width without informing Prusa.

This situation explains why the issue affects only some of the printers with MMU and not all of them.

RE: How to fix the IR Filament Sensor?

i agree, i love my mk3s. In my opinion it is the best printer available for around 800 usd. It's very reliable can be used as a trusty work horse, perhaps i expected this same level of reliability and ease use with connecting the mmu2s to the mk3s and that has unfortunately not been my experience. I may try it again later, i just don't have the time to spend fiddling with it before every print.

RE: How to fix the IR Filament Sensor?

@marino

Unfortunately I am not allowed to send you a message. Would you be so kind and send the file (or the link) to hunter dot carmina at gmail dot com? Thanks a lot, and a Happy New Year to everyone...

S.

RE: How to fix the IR Filament Sensor?

@sunstarfire

I have discovered that files can be annexed to the posts if they are in rar or zip format, or at least it worked before.

Hope it will help you

RE: How to fix the IR Filament Sensor?

Awesome. Thanks 🙂 I will try.

RE: How to fix the IR Filament Sensor?

@sunstarfire

Do not forget to smoothly sand the top of the printed chimney to better host the cover (only few strokes). I have used a P360 grade sand paper (my references are European) over a mirror/glass (cheap solution for a flat surface).

RE: How to fix the IR Filament Sensor?

Printing it now, sanding will follow. Guess most of us are Europeans 🙂 (Austrian here). Thanks, I will report back.

S.

RE: How to fix the IR Filament Sensor?

That did the Trick, @marino. Thanks for the work 🙂 Now changing filaments works flawlessly. Awesome. Have a great New Year everyone, not hard, seeing how bullshit the old one was.

RE: How to fix the IR Filament Sensor?

@shilbert

Hi, I´m just printing TZB´s parts for the MMU2s filament sensor / extruder part you recommended above. Is there a picture how this thing will be mounted to the extruder once finished? I guess I will figure out only after having halfway disassembled my MMU2s-Extruder....

Thanks, regards

Chris

RE: How to fix the IR Filament Sensor?

In the meantime I figured it out with the help of youtube 🙂

RE: How to fix the IR Filament Sensor?

@marino

If you zip files before attaching them, that should work.

RE: How to fix the IR Filament Sensor?

@stewartr

Thanks for the hint. There is always room for improving my knowledge.

Do not forget to smoothly sand the top of the printed chimney to better host the cover (only few strokes). I have used a P360 grade sand paper (my references are European) over a mirror/glass (cheap solution for a flat surface).

RE: How to fix the IR Filament Sensor?

I am interested in  shilbert 's response about TZB, but I do not see clear explanation about what/why how that fairly complex mod is needed and what good it does.

Meanwhile, I had a completely useless IR filament sensor setup with stock MMU2s tools, though the sensor itself was provably fine. I spent over a week emailing Prusa support about what to do and reprinting stock parts and sending them video and fiddling with the screws on top. Nothing completely fixed things. At one point, I could get my allen key recognized but still not filament. It was driving me crazy.

I bit the bullet and built this:

https://www.thingiverse.com/thing:3554066

which is recommended above by @ petr.f12

This IMMEDIATELY solved my IR sensor problem. As in, the problem is nonexistent now.