RepRapPro Mendel has started stuttering recently during prints, leading to failed prints. Has anyone seen a similar issue?

I've recorded a brief video that shows the stutter occurring right at the start of a print: [vimeo.com]

Homing in x, y and z is smooth, bed heads up fine, hot end heats up fine. I'm guessing there's a loose wire somewhere but I'm not sure where to start or how to troubleshoot something like this.

Here's what I've tried thus far to no avail (problem repeated at some point along the way for each of these conditions/tests):
- Updating to latest firmware
- Disconnecting and reconnecting my hotend cables (the connector is not great and is my likely candidate for failure)
- Tried printing directly through Repetier-Host v 0.90c
- Tried printing directly through Octoprint
- Disconnecting the slave Melzi controller

I've also started noticing errors like "Recv: Error:Line Number is not Last Line Number+1, Last Line:5" in the past few weeks as well, sometimes this error correlates to the stuttering behavior. Prior to this starting in the past week or so, I'd been printing since April without any similar issue.

Edited 1 time(s). Last edit at 07/30/2013 07:55AM by PierreB.

Video doesnt work. says acess denied.

Slave Melzi controller? I've never heard of anyone doing that. What is your electronics set up?

I could not see video, but I would guess some of the extruder motor wires is breaking due to the flex action of x-carriage motion, causing intermittent extrusion failures and stuttering noise.

twitch Wrote:
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> Video doesnt work. says acess denied.

Whoops, had the wrong URL pasted. Should be fixed now

bryanandaimee Wrote:
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> Slave Melzi controller? I've never heard of anyone
> doing that. What is your electronics set up?

I'm building a tricolor mendel, so the slave Melzi controls the second and third extruders and hotends.

Edited 1 time(s). Last edit at 07/30/2013 07:57AM by PierreB.

My RepRapPro started doing this recently with the same message. The solution is to print from SD card and not over USB. The slave communications slow down the USB too much so it's no longer usable for sending gcode. Recent updates to the firmware from RRP seem to have made the issue worse.

Andy

Edited 2 time(s). Last edit at 07/30/2013 11:05AM by ajayre.

ajayre Wrote:
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> My RepRapPro started doing this recently with the
> same message. The solution is to print from SD
> card and not over USB. The slave communications
> slow down the USB too much so it's no longer
> usable. Recent updates to the firmware from RRP
> made the issue worse.
>
> Andy

What's your preferred way for printing via SD card? I've tried doing this through repetier-host without luck. My procedure was:
1) insert SD card into USB dongle to make it accessible as a drive on the PC
2) copy gcode to SD card
3) insert SD card into Melzi
4) try to view files on SD in repetier-host (wouldn't work)

I ran into this exact same issue a couple of days ago with a RAMBO card and Repetier. I tried resetting the board and restarting Repetier, but neither one fixed the issue. Then I restarted my computer, and after that everything worked correctly. The only thing I can think of is that there's a bug in the serial to USB driver, and rebooting reset the driver.

Seems like an issue related to repetier-host, although I can't figure out what. I rebooted the computer, tried a new USB cable and neither helped. I switched back to pronterface and it started printing right away. I have seen since weirdness in terms of machine behavior in the last release or two of repetier-host, so I guess I'll mark it up to that for now.

I had the same issue last night. My motors were skipping and stuttering. Turns out my drivers were getting hot. Put a fan on your drivers and electronics and see if that helps. Fixed my issue right away.

I use pronsole, so it's:

- program SD card on PC
- insert SD card into Melzi
- in pronsole:
connect
M21
sdprint parts.g

Andy

NjEmt527 Wrote:
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> I had the same issue last night. My motors were
> skipping and stuttering. Turns out my drivers were
> getting hot. Put a fan on your drivers and
> electronics and see if that helps. Fixed my issue
> right away.

I don't think it's just motor heat, although possibly for when I've experienced this in the middle of prints. In this case, this behavior was occurring right after the system was turned on after being off for an extended period of time.

ajayre Wrote:
-------------------------------------------------------
> I use pronsole, so it's:
>
> - program SD card on PC
> - insert SD card into Melzi
> - in pronsole:
> connect
> M21
> sdprint parts.g
>
> Andy

Thank you, I'll try this tonight.