OK that was weird, and not cool...

OK that was weird, and not cool… I plugged in my Delta USB, it somehow reset my i3 melzi board. Right in the middle of a print assigned from Repetier Host, printer just stopped. I looked at the LCD and it was reseting as if the power was cycled. 2 different USB ports on the same USB hub to a single USB port on my PC. Any advice or knowledge of this? Will removing that jumper on the Melzi that is supposed to do ‘something’ to USB connectivity fix this?

Also, had a clog, I think, but having issues with last of filament spool feeding with the small diameter bend in the filament. MK8 extruder on Anhao clone. Was printing perfectly, then all of a sudden in the middle of a print it would not extrude except in spurts, leaving patches of build and empty areas, eventually printing in air and building up on nozzle.

Bummed, printer was working super good yesterday, today its been an all day trouble shoot, rebuilt extruder cleared nozzle, did not disassemble hot end and tip though, which I may have to do. Might be the PTFE tube? like 8000m through it and nearly a month of print time on the record in firmware… should I disassemble the hot end heater section completely and replace the PTFE tube and check it all out? Or do these run much longer before replacement normally?

If it kept printing, I am sure there was no board reset. Did you watch your cold end motor? Maybe it was slipping there?
If it was slipping at the cold end, it may be due to a jam in the hotend. The PTFE liner can be damaged if you raise the temperature too high which you might try doing because it extrudes easier at a higher temperature which could be because of a partial jam which might be due to a bur in the nozzle in some cases. Yeah…crap like that happened to me

Thanks Nathaniel I did have that problem, on a different printer though The MiltyKoss had a tiny curl of metal from the threading in between the heater block and the throat of the Mini Hotend (which is awesome btw!). I had to disassemble it to find why filament wouldn’t feed at all. it was blocked by a metal obstruction and was never going to feed without clearing it by disassembly! I have done a lot of hand tapping of threads, it is impossible to not have burs and it is impossible to QC all of them without a serious tumble in tiny walnut shell or something, I do not fault the Mini Hotend at all it is printing really nicely as I type this. Printing as we all learn is not plug and play unless you spend thousands, and even then its not its just paying to make your problems someone else’s when tech support is available.

The i3 though… it reset I am sure of that, power cycled and “3p” boot icon came up, printer reset to a ‘ready’ state from a ‘printing’ state. it was very weird. should add, I was powering up a Duet with USB connection from the same hub as the Melzi is connected to, which I am thinking maybe caused an issue with the USB com port assignment or something? Hub is COM 1 and the printers are COM 4 and COM 7, arduino is on a USB port on the motherboard and comes up as COM 4 normally, the Melzi replaced it as COM 4 and yesterday was the first day I had both connected to USB… also have been using Repetier Host, Pronterface, Arduino IDE, and Duet Web Interface. I suppose there may have been a conflict. hopefully that is over as the Duet is all commissioned and running so I don’t need to use Pronterface as much, it was used mostly for calibration preset buttons and a big console to ctrl-C text from.

The i3 is still being super weird, half a print perfect the other half under extruded. I think its the insane twist and tight radius of this filaments final meters on the spool. its giving me a heck of a time. might have to respool it on something bigger and let it sit for a day or two to ease the bend in it. Did everything but disassemble the MK8 and it feeds filament fine, nice even wire coming out with manual feed. only thing I can find that is really different is the filament is super twisted coming off the spool.

@AlohaMilton when I had trouble with the PTFE tube the one time and the bur the other time, it did not completely block. It was a partial nozzle clog effect. It would print okay for a bit and then misbehave. It would not want to print fast, but would give me less problems at slower speeds.

The one printer resetting over USB stuff makes me wonder if you do not have enough amps available for your USB devices.