Hot end won't reach target temperature

[hcdbey]

I have been happily using a Rostock MAX V2 for about six months. As of today, the hot end fails to reach the target temperature. I am printing PLA at 195 degrees.

The hotend would only reach about 190 degrees and then hover there. I could dial in a higher temperature and it would get hotter but it would stop short of the target. At a target temperature of 210, the hotend reaches 206.

I ran Auto Tune and changed the PID settings. It seems that maybe the temperature is getting a couple of degrees closer to the target but it never gets there.

Does anyone have any suggestions?

[lightninjay]

It is possible that one of your heating resistors has gone bad.

I had one go out on mine and I managed to continue printing with it, but the single resistor left was working overtime, and was exhibiting similar symptoms to those you're describing.

I ended up replacing my hotend with a Prometheus v2, because I wanted to start dabbling with higher temp plastics, but you could also look into performing a modification to your stock hotend which gives it a heater cartridge and screw-in thermistor.

Here is a link to McSlappy's thread and a link to his video showing how he modifies the stock hotends to receive a cartridge and screw-in thermistor.

[AlanZ]

I had the same thing happen on my stock hot end...
It started to fail to reach target temperature, regardless of what temp I set it for, it always fell short.
That means it would reach pretty much any temperature I wanted, as long as I set the temperature higher than I wanted.
Of course, this meant the print would not start, but at least I knew the heat was available.

I wound up reducing the flow on the PEEK fan, and that let the hot end get up to temperature.
I put lots more kapton tape around the heater parts of the hot end, hoping that would let me get the fan speed back up. It helped somewhat.
I then thought that it's entirely possible that the fan shroud has warped and is causing the PEEK fan to cool the heater block as well as the PEEK (I looked at my shroud this morning and it has deformed a bit, so I printed another one and will test that soon.)

In the meantime, I have switched over to an E3Dv6 and it's been working well with its own fan.

[thedoble]

Check the voltage that is being output to your hot end -

Check it at the board, and at the hot end, this will help rule out a cabling problem.

If the voltage is too low, check your EEPROM settings.

[hcdbey]

The problem turned out to be an open circuit resistor -- infinite resistance. Now to find a replacement. Does anyone know the resistance and wattage of the resistors I should be looking for.

[Eaglezsoar]

The problem turned out to be an open circuit resistor -- infinite resistance. Now to find a replacement. Does anyone know the resistance and wattage of the resistors I should be looking for.

See this link:
http://www.seemecnc.com/products/6-8-oh ... g-resistor

[hcdbey]

Thank you Eaglezsoar. Not a bad price for the replacement resistors at $2 each but I am in Africa and the cheapest mode of shipping is $18.25. That cheapest method usually takes about four weeks to get things from the USA to Africa and sometimes things don't arrive at all. UPS is $173.20 and that significantly adds to the price of the resistor. I will see what I can find locally although we don't have the equivalent of DigiKey, Mouser or even Radio Shack.

[Eaglezsoar]

Thank you Eaglezsoar. Not a bad price for the replacement resistors at $2 each but I am in Africa and the cheapest mode of shipping is $18.25. That cheapest method usually takes about four weeks to get things from the USA to Africa and sometimes things don't arrive at all. UPS is $173.20 and that significantly adds to the price of the resistor. I will see what I can find locally although we don't have the equivalent of DigiKey, Mouser or even Radio Shack.

If you can find one, the heating cartridge (30 or 40 watt) can take the place of the resistors but it sounds as though you will have a hard time finding one of those also. That kind of shipping for a resistor is ridiculous.

[barry99705]

Thank you Eaglezsoar. Not a bad price for the replacement resistors at $2 each but I am in Africa and the cheapest mode of shipping is $18.25. That cheapest method usually takes about four weeks to get things from the USA to Africa and sometimes things don't arrive at all. UPS is $173.20 and that significantly adds to the price of the resistor. I will see what I can find locally although we don't have the equivalent of DigiKey, Mouser or even Radio Shack.

If you can find one, the heating cartridge (30 or 40 watt) can take the place of the resistors but it sounds as though you will have a hard time finding one of those also. That kind of shipping for a resistor is ridiculous.

Welcome to the world of "shipping to remote locations". Used to be that way with shipping to Alaska. I had to pay $20 to ship a 16gb micro sd card once. Took two weeks, from Seattle to Fairbanks. It only took me 4 days to drive from Fairbanks to Dayton!

[Eaglezsoar]

Thank you Eaglezsoar. Not a bad price for the replacement resistors at $2 each but I am in Africa and the cheapest mode of shipping is $18.25. That cheapest method usually takes about four weeks to get things from the USA to Africa and sometimes things don't arrive at all. UPS is $173.20 and that significantly adds to the price of the resistor. I will see what I can find locally although we don't have the equivalent of DigiKey, Mouser or even Radio Shack.

If you can find one, the heating cartridge (30 or 40 watt) can take the place of the resistors but it sounds as though you will have a hard time finding one of those also. That kind of shipping for a resistor is ridiculous.

Welcome to the world of "shipping to remote locations". Used to be that way with shipping to Alaska. I had to pay $20 to ship a 16gb micro sd card once. Took two weeks, from Seattle to Fairbanks. It only took me 4 days to drive from Fairbanks to Dayton!

I am amazed when I hear these stories. When shipping exceeds the cost of the item, it is time to really ask yourself if you need it. The various postal systems are taking extreme advantage of the remote buyers.
It makes me angry but when they have a virtual monopoly and price gauging is done by all, the buyer has no recourse except not to buy the needed item. Another example of how unfair some of the people in this world can be.
I used to believe the world was unfair but now I understand the world is beautiful, some of the people on it however can be quite cruel to make a buck. Soapbox retired.