Well it definitely seems like the firmware, motherboard and thermocouple is working. Since the right extruder is not at the correct temperature the thermocouple is telling the motherboard and hence the firmware that it needs to supply more current to heat the hot end some more. What seems odd is that you are using more current on the right hot end than the left and yet the left hot end is reaching a higher temperature. Since you have ruled out the heatsink thermopaste we seem to of isolated it to the heating element in the right hot end. I would say that maybe by switching to a full metal hot end it put more stress on the heating element which caused it to fail. Since after reading multiple places and having the same issue myself with a full metal nozzle, having so much metal causes the hot end to become a heatsink making the heating element stress more to maintain temperature. I’ve noticed this when converting to a full metal nozzle where with a brass nozzle I could get to 260 degrees without issue, I couldn’t even make it to 250 degrees with the metal nozzle. I have a hunch that the heating elements arent the best on the flashforge and that’s what you are running in to. I would propose one last test and that is to replace the PTFE setup (only on the right hot end) and see if you can achieve the correct temperature. If everything is exactly as you had it before switching to the full metal hot end and it still doesn’t achieve the correct temperature, then I would say that at this point it is definitely the heating element. Would you be able to submit a picture of the wires on your hot end for the right extruder?
I just realized I didn’t answer your question about the heating cartridges not accepting the power they need. I believe that the left extruder is accepting the power it needs since anything between 1 and 2 amps is within the range I would assume to be acceptable ie. Between 24 and 48 watts per extruder. Since we have a ~ 350 watt power supply I assume a large portion of the power goes to the heated bed and the rest for the motors. Since there are two hot ends I would assume at least 48 watts for both extruders during heating up which leaves 300 watts for the rest. 300 watts does seem like a lot but I assume 150 goes to the heating of the bed since it’s a large object to heat and maybe another 15 watts go to the motors and the rest is overhead since you should never run a power supply at its maximum rated load. Again this is all speculation based on reasoning. Finally the reason why I say the left extruder seems like it is correct and not the right hot end is because the right hot end is getting more current but not doing a good job at heating. Which leads to my previous conclusion that it must of stressed to the point of failure. Sorry for the long replies but you have me thinking ;P.
Should I upgrade to an 24v 80W cartridge then?
Picture!
The one with the white abs is the right side
You would definitely be able to get to 260 degrees no problem. Just make sure the motherboard can handle such a load. Try asking the company selling the 80w upgrade if the mighty board on the flashforge creator pro can handle the current draw for it. I’m thinking of upgrading my hot ends in the future too because of the lack of heating with metal nozzles. If you do end up upgrading to the 80W would you mind posting to update me on wether it solved your problem or not. I want to see if the upgrade works for you and if it does I’ll probably join you on the upgrade.
The heat shielding kapton tape is intact so the heat should be kept in the hot end which is good. The wires to the heating element look fine too so it’s gotta be a defective heating element on the right extruder. Unless anyone else has any other idea’s I think it’s pretty much case closed and pick up a replacement hot end for the right extruder and it should solve your problem.
I agree. Try the old setup on the worse extruder. Otherwise try a new heater. All else seems functional.
After thinking about it, if both are pulling the same current, and one gets hotter, it has to be a heat sinking problem. The law of conservation of energy says the energy has to go somewhere, and it apparently isn’t staying in the hot end of the setup, unless the thermistor is lying.
You know what you have a point. Don’t know why I overlooked that fact. It is getting slightly more current than the left extruder so it should be getting just as hot as the left assuming nothing of the right extruder is different than the left. In that case a faulty thermistor which gives an incorrect reading would definitely lead to this issue. The only way to verify this is to switch both thermistors and put the right thermistor in the left hot end and the left one in the right hot end. Good catch Ed!
I would say replace both hotends so you will be guaranteed to get a good new hotend
Also, I think your motherboard can not handle it. I think you should shut of the right nozzle, To make sure and try to give the left nozzle all the attention.
I’d agree with this except that when he tested both the voltage and current to both nozzles. The right nozzle ( the one that doesn’t achieve the desired temperature) does get the same voltage but more current. So in theory it should be hotter than the left nozzle. The running idea is that the thermocouple is not telling the truth for the right extruder. it seems that is causing the heating element to continually use the same current as if it was heating from cold start. The only way we can check is to swap thermocouples from left to right and right to left to see if the problem goes away in the right extruder but presents itself in the left. If that’s the case then we identified the problem to be the thermocouple.
I just realised you replied to my post about the upgraded 80w hot end. In that case if you were talking about the upgraded hot ends not working with the motherboard then I agree with that statement and you can disregard my last reply.
I would try swapping thermocouples and plugs at the PCB to see if the problem follows to the other side while heating, that way you know if it’s a faulty thermocouple or not.
Likely, you have broken your heater cartridge when doing the replacement. They have very tiny wires, and are very delicate.
If the same current and voltage is flowing into both heaters and one is hotter, either the themocouple lies, OR the heat is going somewhere it shouldn’t.
The thermocouple would lie if:
- It is defective.
- It isn’t attached to the aluminum block with thermal integrity.
- The wiring is faulty.
- The A-D converter in the microprocessor is faulty (not likely)
- The firmware interprets the reading incorrectly (not likely)
The heat would be going somewhere if:
- There is too much heat conductivity from the hot end through the tube to the feeder block (across the thermal barrier built into the tube).
- Too much cool air across the hotend from a fan.
- Operation in very cold conditions (not possible for only one of two extruders).
Swapping components is a good way to troubleshoot.
I agree with you on that one. Try swapping the sensors to test them and you should see if the problem moves to the left hot end after the swap.
Flashforge Product Inquiry
Mini Wang-Flashforge
1) Improve the installation method of the extruder to have better temperature protection. Because if the extruder is cooled down by the fan, the power will be waste. So, if the temperature is well reserved, 40W is strong enough;
2) If above method does not workable for you. We suggest you change a power supply with larger power, say 400W, then you can have a 80W cartridge heater. Because our current power supply is about 320W, if all electronic components work at the same time, the power supply may not able provide enough power.
Hope this helps. Thank you.
I think that insulating the extruder is a good idea. I have been researching just that. Kapton tape isn’t enough. I ordered some of this http://store.quintessentialuniversalbuildingdevice.com/product.php?id\_product=10 and some tape. Some printers come with insulated blocks.
