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Loud vibration move if power cycled while printing
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Description

If you power cycle the machine while printing through Cura 2 the machine sits for a minute then the printer makes a really loud x move that has a lot of vibration. I know @DaniAO has encountered this issue at least once. I can get footage of this issue if that would be helpful

Event Timeline

tutley created this task.Dec 28 2017, 3:29 PM
karrad added a subscriber: karrad.Dec 28 2017, 3:35 PM

@tutley Was this an X+ move? We park the head in the back right on aborted prints, it may be related

tutley added a subscriber: marcio.Jan 2 2018, 7:22 AM

@karrad it is an X+ move. Maybe the feedrate is too high. @marcio mentioned a threshold feedrate for the transition from silent stepping to the current control mode. It may be right at that threshold. we saw similar vibration in the y when the move was very near that threshold.

karrad added a comment.Jan 3 2018, 8:21 AM

@tutley was this hibiscus?

tutley added a comment.Jan 3 2018, 9:20 AM

@karrad yes i havent checked gladiola. But i imagine it wont be an issue on the gladiolas since theres no stealth mode or current control threshold. This threshold feedrate is F4320 so if cura is telling the hibiscus to move x at a feedrate similar to that value it will be very obnoxious.

Tyler and I identified that the cause of the issue is the following line in USBPrinterOutputDevice.py:

self.sendCommand("G1 X%f Y%f F9000" % (parkX, parkY))

This is part of the "Pause" command, but is also used when the connection is closed.

If a printer is power cycled, Cura detects that Marlin restarts and closes the connection, but not before trying to park the head. The feed rate seems a bit high, but isn't anything that the printer can't handle if the command was issued later. I suspect what is happening is that since Cura issues the command right as Marlin is starting up, the command may get executed before Marlin sets up the acceleration values, and thus it is using some outlandish acceleration values.

One option is to try fixing Marlin, but in truth, Cura 2 should not be attempting to park the head after a power cycle, as the printer would have lost all sense of the coordinate system and such a move would likely cause a head crash. So my suggestion is that Cura 2 is modified so that that parking move not happen if the pause is issued in response to a power cycle.

It's not immediately obvious to me how to implement that, but I'll look into it.

tutley added a comment.EditedJan 3 2018, 10:19 AM

If you start a print and then power cycle the machine then cura closes the connection to the machine. If you click print to restart the print it reconnects to the machine then says unable to start job since the printer is busy. Then when you click abort print and yes, this causes the printer to make this move.

marcio closed this task as Resolved.Jan 3 2018, 12:40 PM
marcio claimed this task.

Checked in a fix, confirmed to work by Tutley.

alexei triaged this task as Normal priority.Mar 14 2019, 11:57 AM
alexei changed the edit policy from "Custom Policy" to "Cura LulzBot Edition (Project)".