Hello,
I've had a Makerbot Replicator 2 since roughly around 2013. Since then I have been able to successfully print....maybe 50 at the most things successfully. This thing has been junk since I got it. I don't claim to know a lot about 3D printing but i have done a lot of reading about the problems I'm having...which are many. I fix one thing, I get a good print and then I can't get it working again for months. Try something else and then its good again....then fails with a problem previously thought fixed. I really just want to throw this thing out the window. But I want to gather opinions, maybe see what suggestions are out there first. My main issues are extrusion/clogging it seems. My latest issue is it won't extrude when starting the print job. If I go to "load" filament, it comes out fine. Then immediately start the print again...and nothing comes out like its plugged. Even though it was coming out beautifully during the "load" function. I successfully printed an object the night before. Trying to print the same thing with same settings and nothing. Here are some things I have done and questions I have.
Replaced the nozzle with a .4mm
Replaced the ceramic insulation/kapton on the heater block.
Disassembled the hot end and made sure everything was clean
Replaced the filament drive with an upgraded aluminum type
Tried different filament
Filament is not binding
Replaced thermocouple

Questions:
How important is the active cooling fan? The one that blows towards the bottom near the nozzle. My ducting broke a long time ago and I haven't replaced that...Not sure how much that would effect extrusion problems though.
I tried a .5 mm nozzle and it worked great with not plugging or stopping, however the print looked like crap. I can't find anywhere in makerbot desktop to change the nozzle size for the slicer. Any way to adjust settings for a bigger nozzle? I know resolution goes down a bit but thats alright as long as the thing actually works
The thermocouple i got is not an oem makerbot thermocouple. Could that be reading wrong and not getting the right temps? Or so far off it would cause this many issues? I just replaced that a few days ago though and these problems have been present for years before that.
I know they have a "smart extruder upgrade". With my serious lack of faith in makerbot and the seemingly piece of junk I have from them already, i'm hesitant to spend that kind of money if the thing is just going to continue being crap. Would I be better off just spending $300 on a cheap printer on amazon? Or other options around that price range....I'm not in the mind set to spend $3000 on another printer with the experience I've had with this thing.
If you were me, what would you do?
Lastly, I know this is a lot of information/venting/and questions. I apologize and I don't expect the perfect answer from any one person...I would like to just compile opinions and such. Thank you for your time with any suggestions anyone may have.