Recently we’ve been having issues with the files stored on a USB. Now this could be just the USB being corrupted, but I wanted to at least present this and see if this has happened to others.
Our H2D (2X) are not on the network so we use USB drives to move files. We bought a new H2D and inserted our Production USB in the machine and started printing a file. Then all of the sudden we get “Failure to parse file”. Now it was printing fine for 2-3 days and then the file somehow got corrupted. When I opened the file on the computer it looked like the base was building and then all of the sudden - the paths just shot off in all directions.
Just yesterday I placed a file on the same USB and started a print. The gcode was read and printed started to print - then I went over to the H2d and saw an error - nozzle may be clogged. Looking at the bed - the first few layers were fine and then all of the sudden I see deposits/globs in certain areas. I stopped the print and removed failed substrate. When I went to start the job over I get - “Failure to parse file”. This was a file that not more than 20 minutes before was read by H2D - now it fails. Open the same file (and context - it was created that day on my computer and moved to USB) on computer - and again the paths shoot in all directions.
So the culprit to me is the USB. But what is weird is the file was fine for months - or in my instance one day - and then during printing there is corruption and the H2D print fails.
Has anyone noticed this before? Any thoughts? So this has happened on an old H2D and a brand new H2D.
I’m going to introduce a new USB and I’ll report back on if I see this again. Thanks
Sounds very much like an issue with the USB stick/flash memory, especially if it’s across multiple machines and reproducible on a computer. Flash memory wears out over time, mostly due to write/erase cycles, but in higher density (NAND) devices also from reads (“read disturb” effect – some storage controllers try to mitigate this issue by rewriting “weak” data but this could also cause side effects).
If the problem manifests only after the drive is used in a particular machine (or computer/reader), then that’s a possible culprit. But seems more likely to be the drive itself.
Cheers,
-Max
There have been some mentions of USB drives becoming corrupted on H2 printers.
I suspect (no data to back this up) a combination of lower performance USB drives and printing with timelapse is pushing these lower performance drives beyond their limit.
Here’s the wiki articke on USB requiremenrs:
Bambu sells these ones, for a shop environment the low profile may not be useful though. I use them and so far no issues.
This is what I worry about. As for USB corruption - they file had been written 1/2 year ago. Most likely wasn’t moved - then all of the sudden (even though it initially loaded into H2D memory) it gives me a fault. Then it won’t read again - move it to computer and then it’s corrupt?
I moved the file that failed just today to another USB (somewhat fresh - maybe a month old) and print is going strong.
So I’m perplexed how the internal memory works. I thought all prints are offloaded from USB and onto internal storage - though this doesn’t always seem to be the case. I wish you can just select a file off USB and say transfer to internal. This doesn’t work this way - correct? It would also be nice to maybe attach a SSD or traditional HD to store files.
There’s an insane amount of fake flash drives out there, designed to accept the first 2gb and corrupt themselves after … Just as food for thought as you find a replacement.
I don’t know when the printer uses which storage… or even how much storage is on-board. It would certainly be more robust if the gcode was read into a more reliable medium, like internal flash or even RAM. Until a power failure, of course… but then it could be re-read from USB if absolutely needed.
It would also be nice to maybe attach a SSD or traditional HD to store files.
Not that I’ve tried, but this should definitely be doable as long as the external enclosure powers the drive separately. Maximum draw on the H2* USB ports is a measly 0.5A (2.5W), which isn’t going to cut it even for an SSD. But a single, self-powered enclosure with a direct connection to the printer’s USB port should work. Only USB 2.0 speeds, so no need to get super fancy on a drive/enclosure either.
I have the parts here to test this theory, if that would be helpful.
-Max
This is how it works but the requested print file is transfered into the internal memory only when it is requested at the start of a print. This file (in internall memory) is then overwritten when the next print is requested. Thus if the file on the USB drive has an issue the problem file will be loaded into memory each time it is requested from the USB.
Sure. If you can add an external USB SSD/Normal HD with external PS then that would be great. I will look into this.
So for the internal memory storage it is volatile - meaning it will erase during power out?
I think Bambu should add permanent storage option to their high-end systems.
No, the last print is retained in memory. You can reprint after a power cycle.
They kinda did by adding a USB port?
Meaning internal - not plugging something externally.
I just checked and the H series printers seem to actually hold 7 of the last prints.