[Closed] pre heat error  

RE: pre heat error

just a update been playing and found that the next time i used petg i got thermal run away, this is getting crazy now.

last print it only happened when the fan came on.

will put a sock on it, do i need the fan on petg any way?

RE: pre heat error

@graham25fox

Use a silicone sock an fanspeed between 35% and 50% for petg. Best results you will get with printing on the textured PEI sheet. If 50% causes too much stringing, increase to 70%.

RE: pre heat error

@karl-herbert

Thanks for the reply.

i have run a sock for some time now, by accident i found to lower the cooling, not had error any more.

finding PETG qiute easy to print.

sounds interesting about the textured plate, may have to get one, one funny thing is i went to print PLA changed profile(not the plate)and found that it would not stick at all.

had to REALLY clean for it to stick, so a different plate may be a good idea then

RE: pre heat error

@graham25fox

Usually the smooth printing plate is better for PLA and the textured one is better for PETG. It's good to have both. The PrusaSlicer settings usually give good results. Important: Before you start printing, the plate should be cleaned with soap and water and free of grease/dust. Additionally wipe briefly with Isopropanol. Don't use Acetone or similar.

RE: pre heat error

Wnat is your room  temperature your pri ter is put?

What was the reason your printer for repair?

One possibility would be to run PID autotuning with temperature for PETG 240°C or ASA 250°C.

RE: pre heat error

@zoltan

the reason for repair was i was getting constant MIN TEMP ERROR, I must say before you ask the printer was in a alcove that was always above 20c.

when the printer came back the fault was found to be bad/ missing part. I had the printer built at the factory so i would not have any problems!

i know they changed the thermistor, but have no clue as what else was done, anyway all working good now thanks for all the help

most of my printing is in PLA

RE: pre heat error

@graham25fox

So I am glad, your printer works fine. Happy printing !!! 👍 

RE: pre heat error

I had a thermal runaway error after having a door standing open a while during a print.

Now I am trying to do a new print, but the nozzle won´t heat up at all. I have tried to blow with a hair dryer and the temp rised so the termistor is not the problem. I have checked the connection on the board and reflashed the firmware, but nothing has helped so far.

Any advice would be of great help.

RE: pre heat error

@reidar

If the nozzle is no longer heating and the thermistor is OK, it is probably due to the heating cartridge. I would measure these times. The internal resistance should be approx. 14.4 ohm (24V / 40Watt).

RE: pre heat error

@reidar

How old is your printer and what is your room temperature. During the last heating trial the temperature did not change at all?

RE: pre heat error

@graham25fox

Wash bed with dish soap, no alcohol, the a few prints with alcohol, then dish soap again.

Small objects or big flat objects always clean with dish soap.

And first layer should be 100% the it sticks better,

Both beds should work, and PLA sticks less on the powder coated, but should work.

RE: pre heat error

@karl-herbert

Thank you for taking the time to answer. I don´t know how to do that, but I have a multimeter. Could you send me a picture or something that could show me where I put the pins on the multimeter. Danke. 

RE: pre heat error

@zoltan

Thank you Sir. The room temperature was 23 deg. Celcius, but I had a door open a while and I guessed that cooled down the nozzle too much.

The printer is one year. 

RE: pre heat error

@zoltan

The nozzle showed a rise in temp when heating with a hairdryer, but I am not able to heat it with the PREHEAT function. 

RE: pre heat error

@reidar

A question, did you buy it assembled or as a kit? Based on the answer would be our suggestion. The most safe would be to open the electronic box and unplug the heater and measure the resistance o  the cable plug.

Or start the preheating and try to the shake a bit with the cable leading to the head, it could be a broken cable as well due to often move , but this could happen when the printer alraedy passed couple miles of printing.

During preheat the bed started to heat up?

RE: pre heat error

@reidar

to measure, switch off the printer and pull heating cartridge plug off the printerboard (unlock carefully). When measuring the resistance, the polarity does not matter.

RE: pre heat error

@zoltan

I bought it assembled, but after that I have taken the extruder head apart and replaced the thermistor ´cuz I broke the cables during an attempt to clean the nozzle after a giant filament blooob on the nozzle/heater.

I will try to check the resistance.

The bed heats as it should.

RE: pre heat error

@karl-herbert

Hello again. Test done. When setting the multimeter to 200ohm there was no response = 1

I guess that means I have to buy a new one? Any suggestions? I have seen some at aliexpress, but I can not say anything about the quality.

Tested some other heaters from an anet a8 that I have  and I got 3,2ohm and 4,7ohm on another one.

How much resistance should there be for this printer (mk3s 24v) ?

RE: pre heat error

@reidar

1 means a broken contact. The MK3 series should have 14.4 ohms:

24V = 1.667A * 14.4 ohms

24V * 1.667A = 40watts

The Aliexpress heater cartridge will work, but long delivery times (cheap but no support). Best qualitiy are the E3D ones. If you order from aliexpress you must order the 24V/40watts for the MK3 series. You can also use 24V/50watts.

I you would use the Anet 8 with 3.2 ohms you will overheat the system:

24V = 7.5A * 3.2 ohms

24V * 7.5A = 180watts

I would use max. a 50watts cartridge, maybe 55-60watts.

If you buy a new cartridge, I would order two, so you have one on reserve. Also a thermistor for the nozzle and the heating bed. These are wear parts that break sometimes.