@Sineos got it! Definitely heard on not messing with internals of Klipper! These are all good points! I’m considering tying a pi 4 or pi 5. Maybe I’m pushing the pi 3B+ too far and the cpu isn’t keeping up? Just. A thought from a guy who knows nothing about how klipper works lol
@KLB i think you might have a good idea with removing the screen via usb. I have a touchscreen on mine, but I use the ribbon. That seemed to work for months with printer 1 without ever crashing once. Problems didn’t start until I added a second printer.
I found these USB power blocker adapters on Amazon
I’ve got the power pin to the MCU taped off but ’m wondering about using this (or just using electrical tape to block the pin) to a powered USB hub that would power the touchscreen
I’m also using a 3B and have been thinking Pi 4 since the USB ports on it are USB 3.
@KLB thats a good thought! I did try cutting the power wire within my usb cable to printer 3 to see if that made a difference. It didn’t seem to matter. I assume doing what I did accomplished the same thing as the usb power blocker. But to be fair, I didn’t use the power blocked cable on crashing printer 2. I’m going to test what I’ve got setup currently (printer 1 on top port of left usb stack, printer 3 on top port of right usb stack) and see what I get in a day or two. I’ll go back after a few days to see if I get crashes and test the power blocked cable on printer 2. I should have tested printer 2 first. I didn’t think about it.
Something else I thought about is if the pi is running some system commands that affect the usb ports like what minicom and screen did that would cause the printers to crash right away. Maybe some system function briefly touches the usb ports and causes the crash. Just a total shot in the dark. But something I was wondering.
I feel that, that’s where I’m at. Let us know how things turn out. I’m going to keep moving to some solution (likely just a bunch of pi zero 2w’s) so I can at least get some form of stability.
So, as for the last test I’ve done. Printer 1 on left top usb and printer 3 on right top usb, printer 1 did crash, but restored after restarting the frameware (so no hard printer restart needed this time.) Printer 3 has not crashed. It took about 24 hours. For fun, I’m going to try a powered usb hub, if I can find good drivers. At this point, I’m just curious what will happen. If I can get just work printer to be stable, I’d make individual pi’s work for each printer.
@KLB hey, figured I’d mention my update. Maybe it’ll make a difference for you. So, for fun, I decided to try a powered USB hub and plug printers 1 and 3 into that. It’s been nearly double the amount of time that I normally get on a good time, but having two printers plugged into the powered usb, I haven’t seen any crashes since. Obviously this isn’t much time for a real test, but it has been almost three days without a crash when normally they’d crash, at best, within 22 hrs, and at worst, several times an hour. Figured I’d mention it. Maybe try a powered usb hub for just the printer and see what you get!
But as mentioned above, I plugged a single, powered USB hub that I had laying around into the pi. I then plugged printers 1 and 3 into the USB hub. It’s been about 62 hrs since the last crash. Already approaching triple the best time I’d get between crashing. I’m nervous to throw printer 2 in the mix, but after a few more days, that’ll be the next test. If, for some reason, this actually takes care of my problem, I’d be interested in finding out why the powered usb makes a difference even when I cut power to printer 3 via cable but still had problems.
I’ll update with my findings. For the sake of completion and others reading my post.
I’ve been thinking it was the USB output / interference / power since we are using Pi 3B’s with USB 2.0 but I’ve seen others using it — do you know if the hub is USB 3? I’m not sure if a powered hub boosts the signal but like you said, cutting off the power pin should make the USB connection just a dumb USB connection.
Yes, keep updating and adding to this — I’m absolutely sure it will help someone in the future.
I’ve been wondering the same thing. Like maybe Linux for these boards has some system control that’s messing with the USBs in some way. I don’t know enough about Linux to know if that even sounds right.
To answer your question, it’s a usb 3.0 hub. My understanding is even if a USB hub is 3.0, there typically is USB 2.0 hardware logic built into USB hub anyway since the physical protocol is different. USB 2.0 devices will use the 2.0 hub where 3.0 devices will use the 3.0 hub logic. So, I’m not sure if it makes a difference if the hub is strictly 2.0 or is 3.0 when there should be both logics within a 3.0 hub anyway.
I went back to Marlin and ordered an official Sovol Klipper screen thinking that it’s probably powered and connected differently.
Some people said it couldn’t be updated and I’ve seen plenty of people say it can – It’s more wasted money since I’ve got numerous Raspberry Pi 3Bs laying around and I bought the 5" touchscreen for it but since going back to Marlin I haven’t had any crashes even on 7 hour prints. I just couldn’t deal with the loss of time and filament
Maybe for my next printer I’ll try the Pi again with a USB Hub
I know the Black Friday deals are going to be too tempting to pass up
I feel that! I was exploring the Creality Sonic Pad, but it never dawned on me (I feel real stupid now) that the Sonic Pad has Moonracker, which means it has the moonracker api. The good news is all my scripts probably would just work if I pointed at the Creality Sonic Pad and updated a few things. I’m finding the Sovol Klipper screen uses Moonracker as well. There’s a good chance I might switch over to using the Sovol Klipper screen or the Sonic Pd now that I understand they also have Moonracker in use. But for now, I’m going to stick with what I have going.
Thanks for the heads up! I was reading that as well when I was looking them up just now. Since I’ve had such a hard time getting this far, I’ll probably stick with what I have going for now
I’m probably going to test for another few days since I plan to use this in a commercial setting, but I have all three printers connected to a powered USB 3.0 hub. I have not had a single problem since doing so. It’s been 3 straight days, which I wasn’t getting even close to that before. I still can’t help but wonder if the PI, OS, or some third-party software is messing with the USB ports in a way that is affecting the printers when more than one port is used. I’ll probably try moving a single printer to another port on the pi itself just to see if it’ll crash.
I’ll call this solved at this point, but I’m going to research more as to why using more than one USB port on the PI itself is doing this. If anything has any thoughts on troubleshooting and researching the PI, I’m more than open to recommendations. I’m not super familiar with under the hood of Linux.
You’d think it would be a power management problem by the pi that the USB hub addresses. but even cutting the VCC line in a USB A to C cable didn’t prevent communication to my printers. The Ender 3 V3 SE, from what I’ve read, specifically was designed so that the USB port does not power the MCU. Maybe the PI’s USB bus controller is crappy and can’t handle the sensitivity of Klipper in my case (even though Klipper works with many other people’s setups without a problem).
I’ll keep researching as I’d really like to know why using a powered USB hub with everything else plugged into the hub fixed my problem.
Thanks all for the guidance everyone! <3
TL:DR Using a powered USB hub plugged into my Pi3B+ without populating any of the other 3 pi USB ports fixed my problem. all 3 printers have been connected to the USB hub and have not crashed once since this change.
EDIT 1: So far, it’s been around a week with zero crashes. Still, I have no idea why this would make a difference with my printers since my Ender 3 V3 SE’s don’t need any power over the USB port (tested by cutting the 5V line within the USB cable). The Pi is 100% doing something it shouldn’t when I use more than one port. But I have no idea what exactly.
This is very good to hear – I ran my SV06 for a week or two with Marlin and it was a joy not to have to constantly be watching for crashes and losing prints.
I just got the Sovol Klipper screen and installed it and am testing it now.
Yeah, I know people are saying it’s a handicapped version of Klipper but if it doesn’t crash and I get some good speeds out of it (which I am) I really don’t care BUT I am keeping in mind your findings about the powered hub and maybe my next printer I’ll try it — I am also thinking there’s something funky with the pi power and USB connection.
I guess this only further proves, in our cases, it’s something to do with our pi3B+ and how they handle their USB data traffic. I’d need help from someone who is familiar with inspecting and troubleshooting traffic. So, as it stands, I don’t think the would will ever know lol.
I’m happy you’ve got your prints working now though! It makes such a difference in enjoying the hobby!
