Print stops at certain point

Ask the MakerGear community for assistance...

Print stops at certain point

Postby morganfree » Sat Dec 23, 2017 11:27 pm

I have an issue that it's causing me headaches!
I've been printing PETG parts with success until a few days ago. It seems that the program is stopped after a couple of hours of printing and apparently "stops" completely, because when I reach the printer, the nozzle is stucked in the part... nozzle cold, table cold. Seems that the printer is actually stopping it reading of the program.
This is happening after 2-4mm of print and it happened 4 times with the same plastic/part. But I gotta say that I've successfully printed several times that very same part with the very same program until a few days ago.

At the beginning I thought it was an SD reading issue, since my reader was a little bit loose. So I changed the card and the reader: same result. The print stopped after 2,5mm.
I've changed the glass for one with PEI... since I'm thinking that might be a clogging issue (I was using just glass with spray on it successfully). Anyway, if it's a clogging issue I can't explain why the printer is stopped completely. Normally I would expect that the printer continues to work with no feeding...

I'm trying now another program with other parts in order to see if that one will complete.
In the meantime, Does anyone have any suggestion about what could be the issue?
User avatar
morganfree
 
Posts: 44
Joined: Mon Sep 26, 2016 10:46 pm
Location: Porto Alegre, Brazil

Re: Print stops at certain point

Postby ednisley » Sun Dec 24, 2017 12:32 pm

morganfree wrote:printing PETG parts with success until a few days ago


There's no mechanical feedback from the printer hardware to the firmware, so that rules out all jams / clogs / stalls.

Because the firmware shuts down the heaters, it hasn't crashed and seized up.

If you're running a moderately recent version of Marlin, I'd lay long odds its thermal runaway detector is giving you false positive shutowns. The room around the M2 is now cooler than it used to be, the bed heater can't maintain the setpoint temperature, the firmware misinterprets that as a thermistor failure, and turns everything off. Because it's running from the SD card, you don't get any diagnostic messages.

You can try disabling the platform fan, which should raise the temperature just enough to get by.

The correct solution is to increase the default runaway parameters in Configuration_adv.h:

Code: Select all
#define THERMAL_PROTECTION_HYSTERESIS 6
#define THERMAL_PROTECTION_BED_HYSTERESIS 6


You may want to double the corresponding PERIOD values, but if the heater can't keep up, a longer period just means junking more plastic.

Recompile, reload, and you're set.
User avatar
ednisley
 
Posts: 916
Joined: Fri Apr 11, 2014 5:34 pm
Location: Halfway up the Hudson

Re: Print stops at certain point

Postby morganfree » Sun Dec 24, 2017 9:07 pm

Thanks Ed.
I'm modifying the values on my firmware... Anyway I don't have all those variables you've mentioned.

I only have these ones:

#ifdef BED_LIMIT_SWITCHING
#define BED_HYSTERESIS 6 //only disable heating if T>target+BED_HYSTERESIS and enable heating if T>target-BED_HYSTERESIS
#endif
#define BED_CHECK_INTERVAL 10000 //ms between checks in bang-bang control

I've modified the hysteresis from 2 to 6 and the Interval from 5000 to 10000.


Should be that enough or should I add all the code you've sent me?

Thanks a lot.
User avatar
morganfree
 
Posts: 44
Joined: Mon Sep 26, 2016 10:46 pm
Location: Porto Alegre, Brazil

Re: Print stops at certain point

Postby morganfree » Sun Dec 24, 2017 9:20 pm

Anyway Ed, the other question would be... Why this sudenly might started? 2-3 days ago I wasn't having an issue like this.
Should be something related to the thermal sensor or the wire on the bed? I'm checking those but I can't seem to find any issue with them (I move and pull them in order to detect some T variation).

Thanks
User avatar
morganfree
 
Posts: 44
Joined: Mon Sep 26, 2016 10:46 pm
Location: Porto Alegre, Brazil

Re: Print stops at certain point

Postby ednisley » Mon Dec 25, 2017 2:55 am

morganfree wrote:I only have these ones


Mmmph, it looks like your firmware predates the thermal runaway code. The values you show determine how closely the platform (a.k.a. "bed") temperature tracks the setpoint, so you shouldn't modify them; change them back to what they were before.

So that leaves another possibility: a failing extruder thermistor. The firmware will notice when the hot end temperature goes out of tolerance and shuts things down to prevent damage.

The temperature graph on the PC should show a consistent temperature, with no jaggy spikes and sudden deviations, throughout the entire temperature range from room to extrusion. Wiggling & jiggling the wiring from the extruder thermistor to the RAMBo shouldn't make any difference, either.

Other than that, I'm fresh out of ideas ...
User avatar
ednisley
 
Posts: 916
Joined: Fri Apr 11, 2014 5:34 pm
Location: Halfway up the Hudson

Re: Print stops at certain point

Postby jk42 » Wed Dec 27, 2017 5:18 pm

Morgan,
I would suggest you contact us a support@makergear.com

Have you been getting any errors? (eg. MINTEMP)
Have you tried printing via USB? (just as a diagnostic)

We would be happy to help you troubleshoot this problem!
~Jason from MakerGear
jk42
 
Posts: 33
Joined: Mon Oct 09, 2017 5:19 pm

Re: Print stops at certain point

Postby morganfree » Fri Dec 29, 2017 3:37 pm

Hello Jk!
Actually, I'm not getting any diagnostics/errors sine I'm printing from SD card and I don't have a display yet. So, I really don't know whats going on.
I could start a print via usb in order to get that diagnostic.

Anyway I'm getting the idea that it's something related to the extruder temperature, as Ed suggested.
The other day I was trying to start a print but the extruder was not heating... Messing a little bit with the wiring, I finally got the extruder to heat... but I'm guessing that eventhough lately I could start some prints, at certain point the extruder stops heating and the printer stops. Now, that makes sense.

I couldn't review the wiring yet in order to check if there's some semicut wire or loose connector... I'll do it next tuesday. I'll also try to start a print via USB and update the post with the diagnostics.

I appreciatte a lot your help!

Best regards and Happy New Year, all of you!
User avatar
morganfree
 
Posts: 44
Joined: Mon Sep 26, 2016 10:46 pm
Location: Porto Alegre, Brazil

Re: Print stops at certain point

Postby jk42 » Fri Dec 29, 2017 4:37 pm

Morgan,

I would suggest the following:

Connect to your printer. Both thermistors should read at least room temperature.
If one of them reads 0, then that thermistor is bad.

If they are reading room temp, heat the hotend up to print temp. Wiggle the thermistor around.
If the temp jumps around then the themistor is bad.

If it doesn't, try moving the extruder assembly back and forth by hand. If you get large temperature fluctuations,
then the extruder harness is bad.

Give this a try when you get a chance.

Please feel free to contact us at support@makergear.com
~Jason from MakerGear
jk42
 
Posts: 33
Joined: Mon Oct 09, 2017 5:19 pm

Re: Print stops at certain point

Postby morganfree » Thu Jan 04, 2018 2:05 am

Hello Jk!

Well, I must tell I was with issues with the two of the heaters!!! :(

First, I proved that the HB heater was with fluctuations of about 6-7 C up and down... so I had to change the heater. Problem solved.
Tested after and my print stopped again: S3D indicated some sort of "protection stop because of extruder temperature issue (something like that)"... so I started to mess with the extruder's heater wiring and found out that the connector was loose.
I directly join the wiring by soldering it and I FINALLY COULD PRINT a whole program!!!

Thanks a lot for the assistance of all of you. Luckily it was simplier than expected (most of the times is like that).

Best regards!
User avatar
morganfree
 
Posts: 44
Joined: Mon Sep 26, 2016 10:46 pm
Location: Porto Alegre, Brazil


Return to Tech Support

Who is online

Users browsing this forum: Bing [Bot] and 5 guests