All Jammed Up Plus aka help please!

[tamcofarms]

I have a problem with the nozzle jamming up. I had problems with the thermistor staying put (cracked the resistors good as the system tried to keep up with the temp) so I followed Gene's video and upgraded to the screw in type and 40 watt heater cartridge. Went through the whole calibration process once more from top to bottom and put it to the test. With 4 layers to go on a 90 minute print the nozzle jams. So I pause the print, try retracting and then extruding to no avail. The temp of the nozzle reads perfect and was the same as it was during the whole print but I can't get it to work.
The only way to clear the nozzle is to remove the nozzle and head to the stove (gas flame) and boil and clean out the PLA that remains inside the nozzle.
This brings me to my second problem by the time I cleared things up I couldn't restart the print, controlling the printer via Repetier was impossible nothing worked so I give up on the print and try to kill the job but it had no effect on the printer. I tried to use the kill switch on the printer and there is no response. The only thing left to do it to turn off the printer.
This leads to a third problem, when I have to turn to the switching off the printer in this situation then the power supply won't switch back on because it is over heated so I have to whip out the can of air to cool things off in the back of the supply and then the machine will switch on.
Any advice will be greatly appreciated!

[JohnStack]

(Kinda hard to read through this one.)

1. What are you trying to print and what settings are you using. Surely, 90 minutes of success and then a problem is probably not settings but let's be sure.
2. Are you using stock everything? Which printer are you using?
3. After 90 minutes, it sounds like your board or PS or Extruder Servo is overheating. Have you tried directing a fan at the board? Is your peek fan running?

[tamcofarms]

I apologize - you are correct '(Kinda hard to read through this one.)' It was the 2:00 a.m. bedtime, 6:00 a.m. go to work rush!
The main problem:
- 90 minutes of perfect printing using white PLA from SeeMeCNC then nozzle jams with only 4 layers left
- Extruder is clunking trying to shove PLA and is continuing to follow gcode to print, so I paused the print job and sent to home position
- Hot end is still very hot, can touch scrap piece against tip and it will melt
- The only remedy at this point is to remove the nozzle and hold over hot flame to clean it out
- Put it back together, it works again

Machine - Rostock Max v2 with standard hot end upgraded with a 12v 40watt heater cartridge and screw in thermistor set in brass standoff. Everything else provided is installed including peek and layer fans.
Object being printed - Dumb little coin with Assassins Creed Black Flag logo - first print after hot end upgrade.
Settings - 211 Celsius, .15 layer height, everything else is default according to the settings from the manual.

I purchased a separate powered little fan this afternoon to direct more through the PS. It seems to be enough to get to the RAMBO as well. I live in Arizona, so temp for the internals could become an issue. If it is I will 'print' me an extra fan mount to replace one of the back panels. After all why have the thing if you don't use it?

[JohnStack]

I purchased a separate powered little fan this afternoon to direct more through the PS. It seems to be enough to get to the RAMBO as well. I live in Arizona, so temp for the internals could become an issue. If it is I will 'print' me an extra fan mount to replace one of the back panels. After all why have the thing if you don't use it?

Have you tried any lower temps with the PLA? I run 190C. What might be happening is this:

PLA really melts and gets soft when printing above 190C. As such, despite the fact that you have a Peek Fan, the heat may be going up enough to get you jammed up.

Lower your heat. You don't need it.

Secondly, you might consider increasing your layer heights to .2. (Sorry, I know you want great parts). Increase your layer thickness, reduce your height, then have some success. Come back and reduce your layer height after...

[tamcofarms]

THANKS!!!!!!
Lowering the temp to 190c seems to have done the trick. It has been printing for the last 7 hours straight without skipping a beat. I wonder why the defaults were set so high in the ini file itself, I got in this knowing it wasn't plug 'n' play which has definitely given me the challenges I was looking for.
Can you give me the temps that you use for the other types of material you use?
Thanks again for your advice!

[guanu]

the reason is all plastic has different properties.. even different batches of the same color from the same supplier can have varying settings needed.. I typicallty print all my pla at 200-205.. just like bed temps, for pla I use about 65c.. abs I do hotend at 222-225 and have my bed at 80-85c

Guanu

[JohnStack]

The best guide I've seen is Lulzbot's:

http://www.lulzbot.com/sites/all/themes ... _Guide.pdf