Print Pausing, Repetier showing 'k' during pause.

[MileHigh3DII]

This just started happening to my Printrbot Plus 2.1 Dual. Parts made in in Cura 3.3.1 (which is also open) and Repetier (1.0.1) and (1.1.0) on my MAC.

Prints run fine, but it seems randomly the print stops and the Repetier log shows the letter 'k'. The print will then usually start again after 5sec to minutes. The x-yt stops, the extrusion stops. The hot end and bed stay on. If it sits long enough, it screws up the print.

I had a longer print that strarted out right and eventually had some 'k's and eventually stopped due to "Communication timeout - reset send buffer block"

I had updated Cura and Repetier and an hour long, 62 layer print had gone fine. I tried the larger 4hr/500 layer print, and it K'd and stopped?

Does it have to do with the new Cura software being on? I noticed that starting with about Cura 3 that the time estimate in Repetier didnt' work. It seems Cura tries to talk to the printer also?

[RetireeJay]

I have occasionally had both Repetier and Cura (or another User Interface) program open at the same time, but I'm always very careful to not allow more than one program access to the printer simultaneously - even if only one program is actively running a print. 99% of the time, I only have Repetier open. I only open up Cura to try to analyze problems posted here. Why would you have both Repetier and Cura open? Repetier gives you access to the "Cura engine" for slicing (at least, the Windows version of Repetier does; I can't vouch for the Mac version).

That said, I've never seen a "k" message. A loss of communications could stem from a problem with your USB port or cable; it could be a side effect of a power supply that's overloaded or failing. Or you might have a thermistor wire that's becoming slightly intermittent due to wire fatigue, although normally that causes an immediate and complete shutdown.

Come to think of it, I'm pretty sure the communication protocol between the computer and the printer involves the printer responding with an "ok" message after each line of G-code is received and successfully executed or buffered. So if there is a poor communication connection, maybe the "o" is getting lost and only the "k" shows up. Repetier doesn't show you all those "ok" messages because it knows about them, but if it sees just "K" then it doesn't know how to interpret that and probably would show it to you. Which leads to the question of whether you have something else going on on your computer that might keep the CPU so busy that it misses incoming characters now and then.

[MileHigh3DII]

Thanks for the insights.

I have used Cura and Repetier at the same time for years. I at one time used Slic3r in Repetier, but moved to Cura after I had issues with Slic3r. I didn't realize that Cura could work inside of Repetier. Like I said, I've done it for years and not had issues- but with older versions.

I did Cura and Repetier seperately because I could have Tinkercad, Cura and REpetier running all at the same time and be working on different models and be tweaking stuff for the next print based on what I was seeing. Most of my prints are in the 1-2 hour print time, so between set-up, slicing and printing and wasting some time on youtube, it was a general slow roll.

It looks like Cura will do what repetier (MAC) will do? That wasn't as much of an option in the past, at least when I started using them.

The repetier log literally looks like

1:08:33 Printing Layer 36 of 501
1:08:57 k
1:09:46 Printing layer 37 of 501

And they are random. Though it could be a loose cable, but everything is tight and the computer wasn't moving. Light load on the processor- and this is a new thing that hasn't happened in hundreds of other prints.

I might reboot the computer, bring up only repetier and let it run a print and see.

[MileHigh3DII]

Seems like it is some sort of Cura and Repetier issue. If I slice with cura, close it, then start my printer and open Repetier, had an hour long print with out an issue.

Used Cura to slice and then to print direct to my printrbot, and didn't have an issue in a 4 hour print. As far as a I can tell since there is no log.

I really like the higher level of control I get with Repetier . Being able to press a button and prime the extruder, change temps and speed on the fly is nice- even tweaking the extrusion multiplier. Cura seems to have none of that. Not even what layer it is on. I guess they expect all that on the device?

I'll try to put Cura slicer in Repetier and hopefully there won't be cross talk between Repetier and the monitor function of Cura.