UM1 randomly heats up to MAXTEMP error during print, burns & smoke

[roo 1]

Hello I've got a UM1 that I use to print PLA at 220 degrees with Cura as my slicer.

Sometimes, for no apparent reason the temperature gets hotter than 220 and heats all the way up until the Ultimaker shuts down with a MAXTEMP error.

It causes the PLA to burn and release smoke, which is worrying because I am in a building with over 500 people in; we have a shared fire alarm system. I don't want to be responsible for causing the evacuation of 500 people!

Any ideas, or need anymore details? I hope someone can shed some light on this.

Best

- Roo

 

[tommyph1208 55]

This happened to me once and turned out to be a loose connection in the thermistor (more specifically, where the wire from the thermistor goes into the small amplification board on top of the hotend)

[ascanio 0]

This happened to me. I used to have more mintemp error and it was due to a loose connection on the cable right in the clip that goes on that microchip over the exteuder... Be carefull my priter ended up pretty bad. I melted the peek insulator which is really bad.... Before melting it I noticed black melted burned plastic over the heatblock. I think it was the peek starting to melt...

[gr5 2,177]

Turn your printer on but don't heat up the nozzle.

Push the print head around to the 4 corners and look at the temp in each corner - leave it there for a whole second before moving to next corner. It should read around 20C (room temperature). Look for the temp to jump suddenly.

Push on the wires at the top of the print head. Look for the temp to jump. Once you get maxtemp it is locked so you have to power off and power on again.

I started getting maxtemp after many successful months of printing. The solution for me was to switch to the alternate cable. The problem was in the existing cable in the connectors. UM soldered those connectors which is bad - the hot solder wicks down the stranded cable and makes the strand stiffer and more easy to break.

Even if you find no issues I still recommend switching to the alternat cable (on both ends of course) and make sure the new calbe is in the black plastic F-shaped strain relief. I added hot glue from a hot glue gun to further add strain relief at the F part.

Alternatively some people have issues with the thermocouple wires down inside the head - keep them at least 10mm away from the fan wiring - there is radio wave interference between the two signals. You don't want the wires touching down there. The thermocouples are very sensitive inside the head but after the signal goes through the tiny board on top of the print head then the signal is no longer sensitive and it's okay for the wires to touch other wires.

 

[roo 1]

Thank you all. I move it around and couldn't get any readings - it was stuck at 8 degrees.

Fiddled with the connector since it seems quite flimsy, but no joy. In the end, switching the the alternate cable solved it, so there must be a weakness somewhere else along the cable. I pushed the heat-shrinked black tube through a bit more to ease stress and for now I've got it working, so I'm happy.

Thanks again

- Roo

 

[gr5 2,177]

8 degrees? That's cold! Are you printing outside? What country are you in (please update your profile to indicate country in case you ever ask a question where the answer depends on the country)?

 

[roo 1]

8 degrees? That's cold! Are you printing outside? What country are you in (please update your profile to indicate country in case you ever ask a question where the answer depends on the country)?

 

I'm actually in the UK - and it wasn't 8 degrees, just an inaccurate reading

 

[gr5 2,177]

Mine has never been off by more than 2 degrees so that's not a good sign :(

 

[JohanJonker 2]

Annoying problems. I have a variation on this theme.

My new (second hand) ultimaker original printer heats up to 250 and keeps the temperature stable during printing the first layer. No problem. However as soon as the fan turns on the temperature increase in a few seconds to 275 and the printers stops with a MAXTEMP error.

I suspect some kind of wiring problem here.

kind regards Johan