Unanswered Extrusion problems after 1 hour

I don't have this problem with my replicator 2. but on my Robo3d it happens quite a bit.

Happens with ABS/PLA..and there is no rime or reason to why.

Basically sometimes it just stops extruding well and leaves balls and starts printing in air. if I kill the print and hook it to simplify3d via my PC and raise the nozzle and hit extrude 100mm it comes out fine.

I don't understand why it keeps happening.

This was 1.5 hours in on a clear PLA print
205 ext and 60c bed heat. .2mm layers

Hard to tell from the picture because its clear but basically its a box with some dividers the right side stopped extruding and left balls everywhere. Its not jammed and not tangled..just seems to not extrude as it should..until i kill it and force it to extrude in simplify3d. And it never happens on the first few layers its always at least an hour in before it happens. Other than this random issue my prints are great when they finish. first layer is awesome everything seems dialed.

Any tips?
I print the same settings on my Replicator2 and have never had this happen ever.
Does it in ABS on my robo3d randomly too.

Thanks

 

I just switched out to colorfabb XT ( which has been printing fine ).. 245 and 70.. and now its doing weird ball stuff on the first layer.

 

Switched over to the Robo stock blue PLA and its printing great... its so random! I don't know if its fillament or settings or whats going on becasue its so random when it just stops

 

Try to loosen the spring tension bolts as well.

 

You may have to turn down extrusion on the xt. When I tried it i had to go below 90 without it balling up.

 

thanks,
I will try oiling I guess never have had to do that before. But i have the problem with ABS too.
My replicator2 has a nice aftermarket nozzle maybe that's why it always just works. I'll try buying another one of those nozzles.

Spring tension bolts were already loose I tried tightening them now.

 

Thanks the XT has been some weird stuff.. I have got great prints and then really bad ones. I saved the settings from my great prints. But its still a crapshoot.

Anyway I ordered this http://www.ebay.com/itm/231227373976?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Because I have this nozzle on my Replicator2 and it has never failed me( the stock replicator2 nozzle got clogged after 75 hours of printing and I couldn't clean it out tried every trick...put this nozzle on it and its never had a problem since ).. maybe that will fix it. It should work on the robo right? I'm using a cheap rep2 mk8 nozzle on it right now.. pretty sure they use the same nozzles.