Prusa I3 MK2s Heating Problems  

Re: Prusa I3 MK2s Heating Problems

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The wiring seems right for the thermistor but when I first wired I did have it plugged into the wrong port: http://imgur.com/GWNXay7 (where the red circle is). Would this have caused it to break?
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simple answer: yes !

in fact, either the thermistor is defective or it has no (or not enough) thermal contact to the hotend.
you've previously put the thermistor into one of the fan connectors. so it probably got the whole +12V voltage and most likely got damaged if it lasts more than a few seconds.
if filament burns and you've got smoke out of the hotend, your hotend seems to be beyond 300°C.

❗ so if the thermistor reads bullshit, you'll probably might damage the whole extruder (even the printed plastic (abs) parts !) because then the cooling with the extruder-fan doesn't start at the right temperature and the whole extruder cover looses structural strenght.

so, shut down the printer before you severely damage or burn anything !

Re: Prusa I3 MK2s Heating Problems

...
The wiring seems right for the thermistor but when I first wired I did have it plugged into the wrong port: http://imgur.com/GWNXay7 (where the red circle is). Would this have caused it to break?
...
simple answer: yes !

in fact, either the thermistor is defective or it has no (or not enough) thermal contact to the hotend.
you've previously put the thermistor into one of the fan connectors. so it probably got the whole +12V voltage and most likely got damaged if it lasts more than a few seconds.
if filament burns and you've got smoke out of the hotend, your hotend seems to be beyond 300°C.

❗ so if the thermistor reads bullshit, you'll probably might damage the whole extruder (even the printed plastic (abs) parts !) because then the cooling with the extruder-fan doesn't start at the right temperature and the whole extruder cover looses structural strenght.

so, shut down the printer before you severely damage or burn anything !

Thanks for the response, how should I go about fixing this then?

Re: Prusa I3 MK2s Heating Problems

get a new thermistor and replace it.
you can get them either from prusa (ask to get enabled for the mk2(s) spareparts section) fitted with a long wire *) for a direct 1:1 swap, or from e3d-online with short wires (you probably need to solder it to your old wire).

*) acutally out of stock @ prusa.

Re: Prusa I3 MK2s Heating Problems

thanks! Also how would I fix the heatbed thermistor giving bullshit values too?

Re: Prusa I3 MK2s Heating Problems

thanks! Also how would I fix the heatbed thermistor giving bullshit values too?

The bed thermistor is only accurate near printing temperatures, and is routinely too low at room temp. I would not worry about that for now.

Re: Prusa I3 MK2s Heating Problems

thanks! Also how would I fix the heatbed thermistor giving bullshit values too?

The bed thermistor is only accurate near printing temperatures, and is routinely too low at room temp. I would not worry about that for now.

when I turn the printer on the heatbed says 25 C and then if I set it to go down to like 15 C it just stays at 25 C. is this normal?

Re: Prusa I3 MK2s Heating Problems

thanks! Also how would I fix the heatbed thermistor giving bullshit values too?

you didn't mention any problems with the heatbed thermistor value at your first post.

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when I turn the printer on the heatbed says 25 C and then if I set it to go down to like 15 C it just stays at 25 C. is this normal?

*rotfl*
yes, that's normal. it's a heatbed, not a cool-bed !
you can't cool down the bed. except when you put a bag of ice cubes on it 🙄

by the way: are you sure that you didn't mixed up heatbed and hotend at the rambo board ?

Re: Prusa I3 MK2s Heating Problems

The heated bed can only be, well heated. If you set it to 15C there's nothing built in on the printer to cool it to that temperature. Its basically like a thermostat in your house for heat. You can set it to 70 degrees in your house but if its 80 degrees the furnace will do nothing. If you set it to 90 and its 80 degrees in your home then the furnace will turn on to provide heat. And like a house with no central air or air conditioning unit, it can be 80 degrees in your house but you want it to 70 the furnace will do nothing because it doesn't have a cooling component.

So I wouldn't worry much about setting the bed temp lower that the ambient readings, that is normal.

Re: Prusa I3 MK2s Heating Problems

thanks! Also how would I fix the heatbed thermistor giving bullshit values too?

you didn't mention any problems with the heatbed thermistor value at your first post.

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when I turn the printer on the heatbed says 25 C and then if I set it to go down to like 15 C it just stays at 25 C. is this normal?

*rotfl*
yes, that's normal. it's a heatbed, not a cool-bed !
you can't cool down the bed. except when you put a bag of ice cubes on it 🙄

by the way: are you sure that you didn't mixed up heatbed and hotend at the rambo board ?

lol yeah that makes sense I just wanted to make sure that it was a normal thing

I did try switching the ports at one point but they're in the right ports now

Re: Prusa I3 MK2s Heating Problems

The heated bed can only be, well heated. If you set it to 15C there's nothing built in on the printer to cool it to that temperature. Its basically like a thermostat in your house for heat. You can set it to 70 degrees in your house but if its 80 degrees the furnace will do nothing. If you set it to 90 and its 80 degrees in your home then the furnace will turn on to provide heat. And like a house with no central air or air conditioning unit, it can be 80 degrees in your house but you want it to 70 the furnace will do nothing because it doesn't have a cooling component.

So I wouldn't worry much about setting the bed temp lower that the ambient readings, that is normal.

that makes sense, thank you!

Re: Prusa I3 MK2s Heating Problems

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I did try switching the ports at one point but they're in the right ports now

I didn't only meant the ports for the thermistors, I meant the heater ports as well.
just to make that clear.

Re: Prusa I3 MK2s Heating Problems

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I did try switching the ports at one point but they're in the right ports now

I didn't only meant the ports for the thermistors, I meant the heater ports as well.
just to make that clear.

what do you mean heater ports? like the power ports at the bottom of the board?

Re: Prusa I3 MK2s Heating Problems

yes, these two ones:

Re: Prusa I3 MK2s Heating Problems

yes, these two ones:
MiniRambo1.3a_heaters.jpg

last I checked they're in the right ports