Five-second pause?

I've been having a blast printing stuff on a Mendel90 built from one of Nop Head's recent kits. Printing a self-designed part as we speak. Which brings me to my point: A few minutes ago, in mid-print, the machine paused for about five seconds, then continued to print normally. The light coloured PLA turned brown where the print paused. I may have seen this brown marks in other prints, but can't be sure.

This is the first time I've noticed this behaviour. It's not a deal-breaker for me, or even a huge concern, but it certainly got my attention. I'll be repeating the same print in a few hours, and the problem happens in an obvious part of the print, so I can determine whether the G-code is the issue.

Has anybody else seen this happen?

Never seen it myself, but my wild guess is that it'll turn out to be that your command buffer was empty. Was your PC busy doing something else at the time? Do you have the ability to print from SD card? Try that.

Gerv

Do you print from the SD card, or directly from a computer? Also, do you select 'monitor print'? If a computer is involved it could cause pauses/interrupts like this.

I just connected mine up to a Raspberry Pi, and use it as a remote interface, but still choose to upload the GCode to the SD card first.

Yes, I would always recommend using the SD card. I get pauses on Win XP over USB if I am doing other things on the PC.

Oddly with my own hardware and software (that uses Ethernet and no command buffering at all) I can run 3 machines at the same and still do anything I want on my PC without it having any noticeable effect.

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[www.hydraraptor.blogspot.com]

Odd that 5 seconds is enough to turn the PLA brown. It normally takes longer than that to discolour.

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[www.hydraraptor.blogspot.com]

This print was from the SD card. Monitor was not enabled.

The hot-end was running at 210 with this PLA filament. (Which is hotter than needed.) The fan for the hot-end was on. So was the bed heater. It might have been more than 5 seconds. It was enough to pull my attention away from surfing, but not enough that I could pull up Pronterface and stop the print. Could have been 10 seconds, but definitely less than 15.

I'm about to start another copy of the same print. If the problem presents itself in the same place, I'll assume it's related to the G-code.

(Marcos, I'm thinking of doing the same thing with an old PC engines Alix box that I have sitting around.)

Edited 1 time(s). Last edit at 12/16/2012 10:14PM by Rural.

It did it. Same place in the print. I'd say five seconds was about right. No singing this time.

If it was at the same place in the print, you might want to look at the GCode around the pause.

As Polygonhell says - as a starter, get your text editor to search for a G4 code ...... and if you find one, see what values follow it - a G4 P5000 will pause for 5000 milliseconds, G4 S5 will pause for 5 seconds.
Saying that, there shouldn't be any G4s anywhere apart from in your start GCode and only then if you have explicitly defined them. Let us know how you get on. Do you know what the Z height was when this happened as you might be able to detect something in the Repetier host simulation. What slicer did you use?

Alan