IR Sensor questions
So I'll admit that I'm confused. I bought a MK3 late last year, and received it a few months ago. Then, along came my MMU2, which was now an MMU2S and included an upgrade to my MK3 -> MK3S. Yay.
So I went through the instructions and upgraded my printer. Added the MMU2S. And nothing worked.
So I'm starting over, trying to get just my printer to work in single-filament mode again, but the IR sensor seems to not be functioning. And oddly, the upgrade directions I followed did not have me install any steel ball or lever, but just an orange plug that acted as a pass-through ( https://manual.prusa3d.com/Guide/3A.+MK3-MK2.5+-+extruder+upgrade/1069 ). So all the troubleshooting guides that talk about magents and steel balls and such don't really help me (like this one: https://help.prusa3d.com/article/43mduc4zdn-ir-sensor-troubleshooting ).
I'd really like to figure out what's going on, as this upgrade has effectively bricked my printer. The MMU2 won't load anything and the IR sensor in the printer is stuck on 0.
Thanks!
RE: IR Sensor questions
Perhaps this is the guide you are looking for:
https://help.prusa3d.com/article/wprwemqsmj-ir-filament-sensor-calibration
RE: IR Sensor questions
The extruder IR sensor can be finicky (mine sure was). Follow the guide vintagepc linked, and then look at your sensor state menu when the filament loads to see what it does. If the IR sensor still bounces, the guide has options on modifying the part. There's another mod you can print if you don't want to modify your prusa-supplied part too, once you get single filament printing working again.
https://help.prusa3d.com/article/wprwemqsmj-ir-filament-sensor-calibration
IR Bounce:
https://imgur.com/a/4ODGSKG
https://www.prusaprinters.org/prints/3417-mk3smmu2s-modified-extruder-idler-mmu2s1-solves-ir
RE: IR Sensor questions
I don't see it mentioned, the MK3S requires different firmware than a MK3. So after the upgrade - if you haven't already done so - you'll need to flash the new firmware.
RE: IR Sensor questions
Thanks, all. I'm hoping to have time tomorrow to get everything reassembled and try the correct guide this time. I'm not sure why it was so hard to find; all the links I pursued led me to the other one, which clearly wasn't the one I wanted.
I did flash the firmware before disassembling. Always try the lowest-cost fix first. 😉
RE: IR Sensor questions
Check also if you've received the correct IR wire cable. In my case I had a cable for MK2.5s instead of MK3s. The sensor pin cable has a different placement like you can see in the upgrade manual.
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram