RE: USB error mid print
Hello all, I have more to report on this. So last night I started a 16 hour print on my 5-tool XL with a brand new Prusa PETG roll. I have seen this issue now with two different Prusa Filament spools (PLA and PETG), where the filament becomes crossed or appears stuck to other filament strands or the spool. I came this morning to find the printer stopped, the filament stuck because it has crossed and would not budge, and the printer reporting the USB drive had unmounted and please re-connect. I unloaded and fixed the filament, but nothing would get he USB port to see a drive until I rebooted (power cycle) the printer. I'll do more testing, but I wanted to let others know. Once I cleaned everything up and did a power cycle, everything was fine and I started the (long) print again.
RE: USB error mid print
I have now the same problem. It started once per long print, but now I have it showing up every 30 minutes or so. I did already try
- different sticks
- power cycle
- adding another in between cable
- Printing petg/pla/.. (long shot)
And a few other things, but the problem seems to get worse. Anyone any other ideas?
RE: USB error mid print
Sorry, no idea. From time to time the filesystem and the partition table of my USB stick get damaged. After creating a new partition table and an FAT32 file system, I can use the stick again. There is still a bug in the firmware regarding the USB system, but I don't know, wether the developers are knowing this, or not.
RE: USB error mid print
I think I have found the solution to these problems:
There are multiple clients from multiple threads which can access the USB stick:
- The printer
- Prusa Link
- Prusa Connect
Each of them have likely some threads reading the drive. As long as it is empty no problems happen, but as it fills, 2. and 3. are starting to be more active on the USB stick. And sometimes they collide with the printer - in which case the printer will not be able to access the data and gives up. Sounds like a bug.
However - workaround: Turn Link and Connect off and/or clear the memory stick.
I was down to a problem every 20 minutes - turned off Link and Connect and now it seems to work. I will test more - I'd guess that Connect is really the problem here - but at least I can print again - and it may also help others! Will update as I find out more!
RE: USB error mid print
I was running 5.1.2 without errors for hundreds of hours and just upgraded to 6.0.0. I have been unable to finish a print since without seeing this error. First one I was able to resume second and third I could not. Have tried a different USB with the same file and it failed on a different layer.
Just emailed support hope they have something useful as my printer is a brick now. Going to try reverting to 5.1.2.
RE: USB error mid print
Yepp, that was what happened to me too. Try to disable Prusa Connect - and then it seems to work (at least for me).
Looks like that they have some kind of blocking read going on and the http server is somehow blocking the printer from access.
Let me know if it fixes it for you! I did contact Prusa already about it and it appears that they know.
RE: USB error mid print
This happened to me too. I reverted back to 5.1.2 for the time being.
I was running 5.1.2 without errors for hundreds of hours and just upgraded to 6.0.0. I have been unable to finish a print since without seeing this error. First one I was able to resume second and third I could not. Have tried a different USB with the same file and it failed on a different layer.
Just emailed support hope they have something useful as my printer is a brick now. Going to try reverting to 5.1.2.
RE: USB error mid print
I reverted to get some prints done but I'll try it later with Prusa Connect off. I haven't received a reply from support yet.
RE: USB error mid print
I have also been having the same issues after upgrading to 6.0.0, thanks for the hint on disabling Prusa Connect.
RE: USB error mid print
I have also been plagued with this issue. It only seems to happen with long, muti-color prints (I have a 5T XL). Stops randomly, inducing power panic usually allows it to resume (for a while). Maddening because I am losing so much print time (it inevitably stops in the middle of the night). Here is what I tried:
- Replaced thumb drive with 2 different "high reliability" drives. Prints still inevitably failed on each.
- Bought a Triplight UPS in case power fluctuations were causing it. Again, problem remains.
- Used a USB extension cable
- Rigged a heat sink to the USB stick
- Completely reset and re-calibrated the printer
-Upgraded to 6.o firmware
Still have the problem.
I have used different models, so I don't think it is a gcode issue
Sadly, I was convinced that it had something to do with the USB port, so I setup a raspberry pi and octoprint and started using it via the back port. That seemed to work. I got through 2 18 hour prints with no issues, but on the third print it failed about 16 hours in. I am now beyond frustrated.
Unicorn3D, do you think that using the Octoprint solution invalidates your theory? I will definately try what you suggested, regardless.
I can't understand why this bug hasn't been discovered and addressed by Prusa. They have XLs running around the clock!
RE: USB error mid print
I forgot to mention that in one way, using octoprint made matters worse because once the freeze happened, I wasn't able to invoke power panic to restart the print. I ended up wasting a lot of plastic as well as time.
RE: USB error mid print
I forgot to mention that in one way, using octoprint made matters worse because once the freeze happened, I wasn't able to invoke power panic to restart the print. I ended up wasting a lot of plastic as well as time.
RE: USB error mid print
I haven't had this error since upgrading to 5.1.2. I recently upgraded to 6.0 and totally corrupted the usb key, I was able to do a full format and recover it but took several tries. Also PrusaLink no longer works, tried multiple things thinking my wifi connection was corrupt. I tried PrusaConnect for the first time and no issues at all. I've been using the printer mostly one head or petg with pla supports without issue. I did try a couple multicolor prints with up to four extruders, also no issues.
We have a MK4 at my work and it too has had multiple issues with the USB getting corrupted or the wifi will stop working. In both cases if you fiddle with it enough you can recover. I'm thinking they have some low level firmware or driver issue that still hasn't been totally solved.
RE: USB error mid print
So, I was printing now a lot of bigger projects (long, colorfull, ..) since more than a week using 6.0.0, and turned PrusaConnect off - and no problems anymore.
Prusa customer service came back to me on this and mentioned I should turn on "Supports binary G-Code" - But I did have that already turned on. Beside that I didn't hear yet back.
So - my recommendation: Try without PrusaConnect for now and it should potentially work (unless you have a differnet problem).
In regards of Octoprint: I cannot answer. I have to admit that I never used Octoprint as I started my 3D printing hobby with the Prusa XL (well - I had a not much used Ender for some years).
RE: USB error mid print
Thank you! I will try this and let you know how it goes.
RE: USB error mid print
Awesome - thanks!
I assume that the more people state that this is a problem the faster soeone will fix it. 🙂
RE: USB error mid print
I assume that the more people state that this is a problem the faster soeone will fix it.
It will probably be quicker fixed if someone makes a post over at Github and people vote it up or comment under it.
RE: USB error mid print
I do not have proof of it, but I am afraid it looks more like a hardware problem ... Firmware can be adapted in ways that it can recover from faults ... That might work for simple data errors ... But if the phy at a certain points gets hung up, only a repower / brownout can solve the issue (put very simple). That's whant some have seen aready. I am no USB expert, but know enough about differential pairs (i.e. HDMI PCB signal routing) to see a problem here.
What can be said for sure is that Prusa did not design the USB connection according to specification. The data lines of USB is a differential pair ... it needs to be run in a twisted way. In the XL design it is just part of a long flat cable.
In a twisted pair influences through electric and magnetic fields get canceled out. It might work for short cables like in the MK4 ... but the long cable in the XL simply might be too much. And for many printers it seems to work ... but some of the more unlucky people have problems with it.
I am one of the unfortunate persons ...
What was done so far:
Using cheap and slow USB sticks help ... less transfer rate and smaller packet sizes reduce the chance of unreadable bits or protocol errors. For exampe the Prusa delivered USB stick worked quite well ... my "high" quality SanDisk USB-3 sticks were a pain in the butt and basically unusable. I received a couple of ADATA USB2 sticks that worked similar well. So maybe a good hint is not to go for high quality fast sticks ... maybe the cheapest swag sticks might work her better. That was fine for quite sime time.
But you might have recognized the past in my description ... Since Firmware 6 and the quite cool feature of the phase compensation things got worse again. I had two USB breakdowns since I use this firmware (connect turned off). I was able to resume after reseating the USB stick. But I don't think it is a problem with the USB software stack ... It merely is a result of the more aggresive driving of the stepper motors (theory only). The phase jitter and more aggresive rise times cause more EMC disturbances. That has a larger impact on the USB data transfer.
Using bgcode also points into this direction .. for the USB tranfer itself it does not matter what the contents of the files are. bgcode just is smaller. So less data is transferred which also results in less likliness to have bit errors.
Overall the system seems to be on the edge ... it works for days ... (I have no glue how much is caught by the error detection and repair mechanism though) ... and at a crertain point an unrecoverable error happens. Even ignoring lost time end energy costs ... (heat bed) ... if you have trouble recovering you in addition wasted a lot of material.
So from the hardware point of view ... what can be done ...
- What I will try the next time I am tinkering with my XL is to twist the cable (maybe in turns of 5-7cm) ... as long as the cable is long enough to do so. That already might cancel out some of the interferences.
- If this does not work properly the next step would be to disconnect the USB data lines going to the display unit right at the main board and use a USB extension cord connected right at the main board and put it in some convenient location. From my expectations that should solve the issue for good.
I don't have a valid theory for the prusa connect issue ... but it might also be additional EMC issues due to the higher WLAN activities.
It is a shame that something like this is needed for a high cost device. But design problems happen. What shouldn't be happening is leaving the users of such a device out in the rain ...
Maybe they can work out a software fix to solve the issue (safe recovery from broken USB connections in any circumstances) or whether they send out replacement cables to the display unit. ... But it should be solved ...
I currently don't have the measurement equipment on hand to do a proper signal integrity evaluation on my printer ... So everything is theory, but somewhat founded one. So I don't want to do any finger pointing. But maybe this is the path to go down to fix the issue for good.
- Made by me -
RE: USB error mid print
This is a great theory. I too will try what you recommend. I'm also looking to see if I can find a shielded USB cable that I can connect to the main board. At this point, I'll try anything. I wish I could consistantly recreate the error. Like you say, it is an enormous wast of time, material and power.
Thanks for the tip.
Has anyone posted this problem to github? If not, I will.
RE: USB error mid print
OK, I have entered the bug at https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/3983
Please upvote.