I appreciate it! I don't want to pull any help away from OP if they still need it though...
So here is my set-up.
Solidoodle 3, Printrboard Rev E, Stock PSU, Stock everything else also, aside from the new E3D V6 12v Direct...
Firmware has been updated accordingly (thanks to many posts here!)
The 12v cooling fan is directly wired to it's very own PSU with nothing else connected, solid 12v there.
I have read and re-read and re-built the E3D V6 about 4 times now, following instructions extremely close just to make sure nothing is wrong. The PTFE tube IS there, seated in the heat break. The only thing I did slightly wrong there is that I have no PTFE sticking out of the top of E3D, and they say to have some up until just about the drive gear. I had not had issues getting filament to feed into that though... the gear/filament line up pretty nicely too, it's not binding on it's way in.
I primarily print with PLA, but I have tried printing with ABS also to see if it was a filament issue...my PLA is brand new, just got it last week from Makergeeks (makergeeks brand, white PLA), and on my old hot end set up it was working just fine...
So what happens is when I start a print, it will lay down the first layer, maybe the first two beautifully, but then as it gets into infill and it's like the nozzle just stops putting out filament, eventually the extruder drive gear just grinds into the filament, and it will not push more through, even with the tensioner set as light as I can get it.
What I find strange is that when the extruder/hot end are at home position (or just parked anywhere), and I manually extrude it flows just fine, I can set it to 100mm extrude and it goes right though it. I have calibrated the extruder, and it is very very close to pushing 100mm when I say to push 100mm, it's within 2-3mm anyway. If I let it try to print while "jamming" for too long, I have to up the temp about 10-20 degrees more to be able to extrude again. Both PLA and ABS do this, and same thing, if it's parked, no problem extruding. I have experimented with various retraction settings between both filaments also, same results. A few times I have cleared the goop in the hot end and some of it came out... like clear film.
I suspect what may be the issue is power supply, I have the stock Solidoodle 3 PSU feeding the REV-E, which if I recall is rated 12.5A. I wonder if it works while parked because nothing else is really drawing current, but when it's printing the other steppers, heat bed, etc. are all pulling, maybe maxing it out, and dropping hot end temps. Though I have not seen that fluctuation while watching RH, so that's a mystery somewhat.
I have a new 12v 30A PSU on the way (found from links on these forums, and recommended by many here). So that's another $25 out of my pocket for something that doesn't work right now, just in the hopes that's an issue, but at least I will have a lot more capacity for upgrades regardless.
I've spent many hours reading forums and suggestions and can't seem to come up with a solution yet. Help!