Nozzle heater turns off while printing

Hi everyone,

at first, excuse my bad english
.
So here is my problem:
During a print, no matter which file i choose (on of my self created or downloaded and sliced with slic3r), at some point of printing the heating of the nozzle suddenly turns off. Some material can be feeded after that, but then it turns hard and the nozzle kicks the (half) printed part off the bed. The temperature shown in the web interface is the real temperature - it is decreasing.

I tried to print a part 4 times. Every time the same symptom at the exactly same place.
While printing a different part, i have the same problem. Sometimes the extruder and the other axes even go crazy and do the weirdest things in a very fast speed.

I tried changing the power supply, formatting the microSD-card and replacing all the files. It did'nt help :-(


Hope you can help me..

Greetings from Germany.
Flo

Hi Flo, sounds like you have a loose thermistor connection. I suggest you check the connectors on the Duet and the ones at your hotend again

If that doesn't help, post the content of your message log.

Where can I find the message log?

If it was a loose connection, I think it would not happen every time at the same time/place?? After restarting the printer, everything is okay - and the decreasing temperature is shown perfectly...

Ahh, at the same point it stops you say? Sounds like you're using an ancient firmware version. Which one are you using? You should be running at least version 0.78.

The message log can be found on the Web interface, but I guess you've been using Pronterface instead.

Edited 1 time(s). Last edit at 10/24/2014 10:26AM by zombiepantslol.

It's 0.78c, i think it's the latest - if not, where can I find newer ones? The website is a little bit confusing..

No, i've been using the web interface all the time. I will look at the message log the next time, thank you.

Got some other ideas?

Thanks in advance.

My guess is that you have a loose connection somewhere at your thermistor wires. If the firmware reads bad temperature values, it will automatically shut down the appropriate heater and a temperature fault will be reported in the message log. If that isn't the case, you can upload your G-Code and your config.g file somewhere and I'll have a look at them.

RRP's official firmware version is 0.78, but my firmware fork has a lot more features and a much better low-level networking system. You could also try out dc42's firmware on which my firmware fork is based on.

i had a similar problem. with the temperature suddenly plummeting during mid print. The problem turned out to be a bad connection between the duet and the heater cartridge. Try checking the resistance on the brown wire and the one next to it and see if you get 3.8 ohms ( on the loom , duet end )

Now the printer is going totally insane.

After not printing in 2 weeks because of time reasons, I tried it again a few days ago. I checked alle the wirings, which were okay, but anyway, I renewed them.
Now I wanted to print a simple art object, just to test the whole printer...

It's just going crazy now. After 3 print attempts of the same model, it still does not work.

It's always the same point of time where it fails. The printer suddenly starts homing all axes (WHY?!), and continues "printing" at about Z0, which has the effect of kicking the model from the bed.... Then the Z axis lifts, just as where it has to print, .... But that's already to late..

What the **** am I doing wrong?
The GCode says nothing about Homing any of the axes, except for the end of the print.

I attached a photo of the three failed prints, and a Video link where you can see the problem.

I just want to print :'(



VIDEO: [youtu.be]



EDIT: All your alternative firmwares are very interesting, but there isn't any manual how to install all this onto my printer without being a total expert of this.... :-/ In those moments I really regret spending that much money for this printer :-!

Edited 1 time(s). Last edit at 11/14/2014 01:45PM by kizashi.

Hello kizashi, I understand your frustration.... with regards to the alternative firmwares available, they can be loaded exactly the same way the official firmware is loaded, just by changing the name of the firmware version on your bossac command. However you should read the release notes before using any of the alternative firmwares just to make sure everything is in order before you turn your printer on. One other thing, have you tried a different slicing program or a different version of the slicing software?

Hello moameen,

thanks for your reply.
I already tried using dc42's software, but weren't able to turn heaters on or print something...

I've been using Slic3r all the time, in its newest version.
Are there other/better slicing or controlling programs?

Quote
kizashi
Hello moameen,

thanks for your reply.
I already tried using dc42's software, but weren't able to turn heaters on or print something...

You probably either didn't have the correct M563 command in config.g, or you needed to send a T1 command. If you are now using RRP 0.78c release and able to control the heaters, you should be able to switch to one of my 0.78 series releases without changing config.g or any of the other files in the /sys directory on the SD card. But if you are using the web interface, you wi9ll need to switch to my version of it.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

There is no fault I can think of that would result in an uncommanded homing. Even if the Duet resets for some reason, it will not home (unless you have a home command in your config.g file).

As you say that it is always in the same place, it is almost certainly something in your print file that is causing it. Perhaps you could zip the file and upload it for us to take a look? If you do, could you also give an indication of the Z height where it goes wrong (you could measure the height of one of the failed prints as accurately as possible)

Dave

As it is a really small file, i didn't zip it. So here it is:

Dodecaeder.gcode

It happens at about 4.5 mm above Z=0.

I already ran it through some gcode simulators. No problem at all...


Greets
Flo

I cannot see anything in your gcode that would result in the printer homing or doing anything untoward between 4mm and 5mm height.

I do however note a few settings that are unusual:

You have set to infill every 10 layers. With a layer height of 0.24mm, this will result in the infill layers being 2.4mm thick, which definitely cannot be achieved. The model you have sliced does not however contain infill (except a layer of solid infill at the base and top), so the setting has in this case had no effect. The default setting is 1, and that is what should be used unless you have a layer height of 0.2mm or less, when it could be set to 2 or at the most 3. Other parts you may slice that contain more infill will not print with a setting of 10 - I suspect that the extruder will try to push far too much material and start skipping.

You have the nozzle diameter set to 0.3 The Ormerod is supplied with a nozzle of 0.5mm as standard - have you fitted a smaller nozzle or is that setting incorrect?

You have set absolute extruder moves. The early Duet firmware only supported relative moves and so that is what most of us use, and I believe still the recommended slicer setting. However your start code is set to put the printer into absolute extruder mode and the latest firmware supports it, so it should be OK.

The Z move speed is faster than the printer is capable of moving the Z axis. This will however be limited by the firmware to something sensible, and so again should not affect your print in practice.

The XY move speeds you have set are achievable, but you have not set maximum move speeds in the start code, so unless you have done so in your config.g file instead, the printer will print slower than the speeds you have selected because they are faster than the default speed limits. You should therefore include a line in your start code such as:
M203 X6000 Y6000 Z500 E3000 ; Allow 100mm/s speeds

If you are 100% certain that the Gcode file you uploaded is the one you are actually printing, it is possible that the Duet is crashing during the print. This is usually due to noise on its power supply or a low voltage, and can sometimes happen at the same place in a print when a move combination creates particularly large voltage spikes on the supply.

Are you printing direct from USB or from SD card? You should not print from USB, so if you are, copy the file to the SD card and print from that.

Does the printer share a mains wall socket with other devices (via an extension lead or multi-way socket)? If so, re-arrange so that the Ormerod is plugged directly into a wall socket that is not used by anything else.

Ensure that the Duet is being powered from the 12V supply and not from the USB. Many computers do not supply clean USB power that has sufficient current to reliably power the Duet.

Do you leave the USB connected while printing? If so, try using the web interface to control the Ormerod and leave the USB unplugged, or unplug the USB after starting the print and see if it still crashes. Noise can be induced into an earth loop between the 12V PSU and the computer's USB socket.

Dave

Hello Dave,

thank you very much for your detailed reply.

I'm powering the duet via the 12V PSU, printing via the web interface.

I've been checking all the settings you mentioned. In some points I see there are mistakes, e.g. the nozzle diameter and the "infill every 10 layers". So I corrected them.

To avoid wasting more material and time, I changed the power supply to a Corsair High Quality PSU, plugged in into a separate wall outlet (before it was plugged into a multy way socket) and printed it with your recommended settings... And I just can't believe it: IT WORKS... yet.

Thank you so so much for your help. I will give further feedback after having printed some more parts :-)))

Flo


EDIT: By the way, what is the recommended temperature for printing PLA? The "ormaxis" parts were printed at 185/65°C. Some other slicing programs recommend about 210°C?

Edited 1 time(s). Last edit at 11/19/2014 12:11PM by kizashi.

Okay, I've been glad too early. Now I'm back to the old problem, which is that the nozzle suddenly stops heating.... What am I doing wrong?d

Quote
kizashi
Okay, I've been glad too early. Now I'm back to the old problem, which is that the nozzle suddenly stops heating.... What am I doing wrong?d

That will be caused by something completely different. The most common reason for the heater to cool down part way through a print is a loose connection on either the heater or the thermistor. If the thermistor loses connection even momentarily, the heater will be disabled until the board is reset. If connection to the thermistor is lost the temperature will read -273. Try wiggling the wires to the hotend connector & thermistor while looking at the temperature readout in the web interface, which should remain pretty steady. A common fault is a bad crimp on a connector, or one of the single connectors becoming loose or falling off a thermistor wire. You can check the heater by measuring the resistance across the + and - heater wires at the Duet end. This should be just a few ohms. Again, wiggle the wires while measuring.

Dave

Edited 1 time(s). Last edit at 11/20/2014 07:45AM by dmould.

Another common fault is one of the pins or receptacles in the 6-pin hotend connector not being inserted all the way, or not locking in place - hence not making a good contact.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi kizashi,

I am fairly new to this as well but just a quick note. Have you downloaded the Slic3r profiles? If not do so by following instructions here and it will save you from tuning all the Slic3r settings by your self. It has worked quite well for me.

Hang in there! The results are worth it!

Best,
Achilles