Printing PLA with the E3D:
Today I disassembled my home made E3D hotend, spent some time cleaning the inside of the heat barrier and made it smoother. The result was not that better - even after seasoning the hotend with olive oil. I still got material flow problems. 
How about replacing the stainless steel by teflon? As long as I print PLA, I’m fine with ~220°C.
I’m not sure how much oil would help in general with whichever issue is affecting your hotend but olive oil would definitely not be the right one to use due to its very low smoke point. Others have used canola I guess but I would think silicone lubricant would make for smooth. Not sure it would be good for interlayer adhesion though.
I’d suggest that you check the wall thickness of the heat break. Did you use stainless steel for that part?
A teflon rod would probably be too soft to restrain the heater block properly, even tough I think it should work from a thermal standpoint.
@Brad_Hopper the idea behind olive oil is to ‘season’ it. similar to how cast iron pans are seasoned. however I did read somewhere that linseed oil might be better for the job.
Canola oil is what I use. Torch it, brush it clean, drop it while hot into a little canola oil. Wipe away residue & excess, reassemble. Then after assembly put a small drop onto filament scrap. Run it up and down fully assembled (cold) hot end. Install. Bring to temp and purge 200mm of filament to get any oil out because the oil kills my adhesion. Wipe off bed. Print.
Since I did this I’ve had zero jams on my E3D on pla.
I know about seasoning pans although I’ve never been so good at it 
This thread prompted me to look around a bit on the topic and I found this, thought you might find it interesting:
http://sherylcanter.com/wordpress/2010/01/a-science-based-technique-for-seasoning-cast-iron/
@Brad_Hopper yeah I think that’s possibly the article I was refering too that I ‘read somewhere’
The E3d manufactured breaks are cut in a specific way to provide a smooth surface finish to the inside of the break, if you’ve not followed the same approach you may have too much scaring on the internal surface to prevent the PLA from sticking. You could always buy and e3d heat break - http://e3d-online.com/HotEnd-Spare-Parts/E3D-HotEnd-Heat-Break-1.75mm
I too have problems with my 1.75 Bowden e3d jamming.
The stock heat brake hole is drilled, not reamed, though they may try to polish the inside hole. I have 5 e3d heat brakes and all of them have tooling marks when looking down the bore.
I bought the extra heat brakes because I have been trying to solve this problem. I put a 1* and 2* taper on the inside bore, extending up into the thin section of the brake. Both tapered heat brakes still jam.
My next move is exactly as you have suggested, Kurt. I plan to create a new heat brake using a 6mm bolt, 4mm ID hole all the way through. Open the hole up in the aluminum heatsink as well, 4mm. Push the PTFE Bowden tube all the way down into the hotend. Or maybe I break the Bowden and PTFE tube into separate parts.
@Thomas_Sanladerer Yes, it’s made of stainless steel. I took a M6 screw and machined it on a lathe. Perhaps the approach from @Adam_Thorp could work.
@Tim_Rastall I’ll buy a original heat break from E3D, but it’s kinda funny when it turns out that I can’t pruduce such a “stupid” peace by myself. 
@Adam_Thorp Your idea sounds good. 
When I first thought about replacing the stainless steel, I planed to completely replace it by PTFE. But your way just “coating” the inner bore might work better.
Polishing: https://www.youtube.com/watch?v=sV1vbFf9XMg
http://www.tridimake.com/2014/03/thoughts-and-hints-around-hot-ends.html
Basically, use sand and a masonry drill bit
If you’re going to use PTFE surely you’d be better off just using a J-Head rather than spending all that time modifying an E3D?
I tried the lowest smoke point oil. Flax seed oil with my e3d. The point with seasoning is to get the oil to polymerize on the inside of the barrel. I spilled some into the hotend and around. The right way is to use a oily cloth or sponge that the filament runs through. Print with it for at least 6 hours and you will end up with a well polymerized heatbreak. No jams for 2 months now. And that is with a bowden, pla and 4.5mm retraction. Printing at 50/60 mm/s but it also works at 200 mm/s or whatever arduino/ramps/marlin is good for. (Speeded up to 500 mm/s but it didn’t continue to increase speed after 200 or so)
it might be worth doing it to the nozzle too, to assist with cleaning it.
Kurt… What extruder are you using in the Graber i3? I’m searching one for me, but the most are another kind of fixation. Thanks
@Donavan_Leichtweis my extruder is based on this: Prusa i3 compact extruder by misan - Thingiverse
Make sure the E3D fits nicely.
