Something that helps a great deal is making the Filament Path have as little friction as possible. You can't use Teflon for the purpose because it decomposes at high temperatures, but you can use 2 other lubricants:
Tungsten Disulfide (WS2) - http://amzn.to/1UBiGog
Hexagonal Boron Nitride (HBN) - http://amzn.to/1ROpa2n
I generally uses the the WS2 spray because it's much cheaper and I didn't see any larger benefits with the HBN spray...
Both of these mechanically-bonded powders; they have to be "wrung into place"; to do that, I use the following process:
- Do a Nylon-Cold-Pull and repeat as necessary to clean/clear the nozzle.
- Open the idler pulley so you can insert the spray tube directly into the filament path
- Cut a bit of filament so that you can bottom it out and still have it be long enough to put into a drill chuck. Nylon preferred; if PLA, make sure the hotend is cold before continuing.
- Using the spray tube, squirt some lubricant into the filament path. Protect the print bed from overspray!
- Insert the cut filament into the hole and bottom it out. Chuck it in a drill and twirl it for 5 seconds
- Repeat 4&5 3-5 times.
- Now do a Nylon-Cold-Pull. You'll find that it is much easier to pull the Nylon out.
I also use the spray to lubricate:
- Hobbed bolt - makes it easier to clean
- Extruder bearings - makes it easier to move even if the gear is on tight
- Y-Axis idler pulley
- Z-Axis screws
I've found that normal chain lube is better for the rods & rails, and YMMV on the idler & screws, but if you lube the hobbed bolt, as counterintuitive as it sounds, it doesn't affect the extrusion force and it makes it much easier to clean out after a jam (use a wire brush instead of picking each slot one-by-one with a razor blade).