Nozzle Overcooling failure?

I just setup my new Taz 4 about a week ago and was having trouble with long (over ~45min) PLA prints failing. After doing some research I added a second fan to help cool the nozzle which allowed me make several prints spanning 3+ hours.

I noticed immediately that if I ran the fan at 100% the nozzle wouldn’t maintain temperature over about 165C. Running the fan between 10-25% kept the nozzle cool and it was still able to maintain 190c with no problems, but I fear it was pulling a lot of amps to do so because it fried the resistor.

Has anyone run into this sort of thing? Does it sound like the probable cause for the failure?


My 2nd Fan runs at 100% and the hotend has no problem maintaining temperatures. I now print PLA at 190 and sometimes 200 depending upon where it was purchased from.

It’s probably a good idea to have extra resistors on hand because I’ve noticed that they become brittle and cracked, even on the extruders with no extra fans.

Kenny

Any idea if this type of heater is more relibable? http://www.geeetech.com/12v-30w-cartridge-wire-heater-heating-wire-p-804.html

Any idea if this type of heater is more relibable? > http://www.geeetech.com/12v-30w-cartrid > … p-804.html

I’ve wondered about that myself, and wondered why we are not using a better method of heating.

We would need a 24 volt version of that heat cartridge.

Kenny