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Does the Ultimaker 3 have a thermal cut off switch/fuse if it overheats?

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Posted · Does the Ultimaker 3 have a thermal cut off switch/fuse if it overheats?

I have an Ultimaker 3.   I am printing an item that takes over 24hrs to complete.   I am printing in ASA that likes a warm environment and no draughts.   I have the printer in a large cupboard and I close one of the two doors to keep the environment warm.


However I worry about leaving home with the printer running.  Could it catch fire or is there a thermal cut out that would cut the power if it got too hot??



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    Posted · Does the Ultimaker 3 have a thermal cut off switch/fuse if it overheats?

    Not... really...


    One failure mode is if the temp sensor is reading low such that the printer thinks the nozzle is colder than desired and it starts feeding full power into the heater "forever".  Well there is a software check - if the heater is on full blast for N seconds (I think it's 30 seconds) and the temperature doesn't go up by M degrees (I think it's 2 degrees) then it knows something is seriously wrong and shuts down the heaters immediately, and aborts the print.


    Also if the temp sensor measures very high temperatures it also cuts off power to head and bed.


    Also Ultimaker tried just feeding 24V into the heater "forever" to see what would happen.  I'm pretty sure what happens is: not much.  I think the teflon inside the head melts out a little bit and needs replacing afterwards.  I don't know if anything catches on fire but I wouldn't want anything above the printer within a few inches.  Other than the print head, I believe the rest of the printer is unaffected.


    If you feed 24V into the bed "forever" it only reaches about 110C.  Not hot enough for anything to burn.  Even if you raise the ambient temp in your cupboard to 50C the bed will only reach about 135C.  Still not hot enough for anything to burn.


    If your printer has the CE certification sticker on the back (I think the UM3 does?) then it's *somewhat* safe but there is no guarantee.


    The servo drivers also get quite hot and have built in thermo cutoffs - built into the servo driver chip.  It only cuts off for a portion of a second and then starts right back up (but your printer loses steps so your print is ruined) but this prevents these chips from getting so hot they would start a fire.


    The power brick should also be CE certified and seems to have a computer in it.  It has safety features and almost certainly a thermal cutoff.  When it cuts off (it's happened to me many times - not sure if it's thermal or current or voltage dip) it stays off until you power cycle it.


    I don't represent Ultimaker.  I don't work for them.  This is all 3rd hand information.  I believe it's not 100% safe but it's reasonably safe.  But safer if like on a table away from all combustibles, lol.


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