Extruder Problem

I've read lots of search results, have not been able to figure this one out, I have a Folger tech prusa i3, if I try to heat it up for first print of the day, sometime it will heat up very fast, most days it doesn't do anything for hours, no change in temp.

next problem is the extruder suddenly not working as it should, yesterday, I was trying to print with PLA, and its clicking at 195c to 254c once print speed above 10mm/s was working well before that, I've cleaned out everything again and again all day to no avail, also had similar problem with abs, tried 3 nozzles, no improvement, looks to be the nozzle temp is much lower than the temp is reading, but, at 245c, I can see clearly the pla is too hot

anyone any idea?

thanks

Sounds like a possible electrical problem re- the lack of heating up (do you mean the heatbed here??). Do not leave the machine unattended at this point as an electrical issue could pose a fiire risk.

Check for voltage at the heat bed, or output from the electronics board (RAMPs?). Possibly the MOSFEt for the heatbed has blown....do you keep a fan on your electronics?

With regard to the extrusion, I might have suggested the PTFE liner in the hot end (if one is present) but you mention youve swapped hotends out. Possibly the extruder tension isnt enough, try tightening the filament tensioner on the extruder.

Also make sure the hot end is correctly lined up with the extruder, ie hot end entry point directly below and inline with the the filament exit point from the extruder. If there is an offset it can cause the filament to grab.

You can also try heting up the hot end, and with the filament tensioner fully released, try pushing filament through by hand, it should come out fairly easily.
HTH

If you already tried various hotends with the same bad result any faul of the theristor can be ruled out.
What concerns me is that you say nothing happens for hours - can specify on that one?

For general troubleshooting:
Check the connections, and I mean all of them!
Power supply connections often use screws and a plug of sorts - double check all is tight.
Check the solder points for the pin header, especially your hotend connector. If it looks like a hair line fracture in the solder you can be sure there is a problem that requires re-soldering.
According to their homepage they use quite cheap components, actually on the lowest end...
If you have a multimeter and you are not scared to use it check the currents and voltages from the power supply to the printer.

thanks for the reply guys

I swapped out PTFE liner for new ones, I also have full metal 1.75mm tube to heater, metal tube is worst, it melts too soon, my multimeter is dead so I have no way of testing voltage at the moment, it happened earlier, after serveral reset by pressing the reset switch, it finally heats up, the board is sitting at a cool point, I have checked it a few times, it never gets a chance to warms up.

the stock extruder has no tensioner and it broke few days ago actually, I managed to do a temp repair to work just long enough to make a new block with tensioner, and it is tighten as far as you can go, when pushing by hand on filament, it is the same, needs high temp, but today its lower temp, I'm lost

oddly today I am able to print at 208c ith the pla, 2 days ago was 195c, printer is enclosed in box but I built it in a weay the boards are outside of the enclosure.

I have since got an aluminium bed, did an autotune, was working well for 2 days, it is weird, everyday it performs differently...

this thing has me pulling my hair out....

found a little missed aligned on the extruder block to the tube, adjusted that and its now printing PLA at 180c still need fan on or it gets soften and click, ABS prints at 235 no fan needed but I have no tape on the bed abd for some reason ABS don't stick to the aluminium bed even at 100c, I read lots of places and the store I got it from says no tape needed, I guess its just PLA