I was done fighting the original hot end.  This is what I did to both my printers. http://www.thingiverse.com/thing:792085
I can now run anything Ninjaflex and wood fill.  It's been great. The pictures are of the wood fill and Ninjafiex first prints. The Pico hot end is nice. Easy to install and very light and small.

You don't have a Duo/Davinci 2.0 though, correct? The Pico install is just on a 1.0x?

I assume that's PTFE tubing you have there to prevent buckling with flexible filaments?

Anyone know if the throat is a standard M6 x 26.5 barrel? Wondering if replacing that with a PTFE-lined one might not be helpful as well. Or is the one in there already lined? Never unscrewed the brass endcap.

You cannot swap the throat, the end that screws in the hotend is a M6 but a smaller thread.

I have been a little inactive these past weeks, but I have now been printing with PLA without problems!
All I do is take off the sides of the printer, lower the extruder fan, and put a desk fan in front of it.  Keeps it nice and cool, makes the layers look nice too!  I use Hatchbox PLA, first time using it and got to say it has been very high quality compared to Shaxon PLA from Fry's, no clogging at all.
After I gather the loot, I'll order some woodfill/bronzefill/copperfill and see what comes up.

I don't have any pictures, because I have given/sold my models to friends.  In my next post I'll show some pics of some prints, and my setup.

I use Shaxon ABS from Fry's all the time and find it to be very good filament for 25 bucks a roll.

I am talking about their PLA, as I once compared it with a friend's MatterHacker's PLA and it really showed a difference.  Shaxon was very flexible for being called PLA compared to MatterHacker's stiff and "snappable", Shaxon's also smelled a bit different; like somewhat smelling candy with a hint of ABS smell (very odd).

There could also be the issue of cheapo filament.  I used Shaxon PLA and I'm wondering if that is the problem too, $24.99 for 1kg.  For now printing with PLA is more like hit or miss, either it goes smooth or some of the layers jam the extruder.
Still experimenting....

~Dom

I use Shaxon ABS from Fry's all the time and find it to be very good filament for 25 bucks a roll.

~Dom

montressor wrote:

Could this issue be resolved by a guide between the geared drive wheels and the throat of the feeder tube? I've noticed that's where I get buckling with PolyFlex and I've been wondering if a guide here could fix that. Tolerances would be a little tight, but seems doable.

Definitely, I was thinking the same thing and was wondering if I could add a small plate of metal underneath both sides of the gears.  So when you feed filament through and extrude, if it ever follows the gear and starts to buckle, the filament will hit one of those plates and will continue moving in a mostly straight line.  I will look around and see what I can come up with...I have been busy with school lately.

I have succeeded in printing PLA again, this time using painters tape as glass is a little hard to stick to unless the bed is leveled perfectly, and I also use a bit of oil to get the filament going.  Using 220c extruded and 50c bed with default slic3r speed.  I also used zip-ties instead of a screw or scobo's ingenious putty mount, using one through the bottom left hole to hold it in place and another one going through the top left hole to pull it up so it does not meet parallel with the hotend.  One letdown to lowering the fan is it also moves it out a little bit, so I  can't move the mount all the way back or the fan will get crushed (or squeezed).  I keep the door open, and I took off the top lid for better airflow and easier to feed filament (I use an external spool holder that feeds through the back). 

Thanks for you guy's help, hopefully we'll get NinjaFlex going soon!

If you are printing PLA and using blue tape you don't need a heated bed. All the highend Makerbots do PLA on blue tape on a cold bed. The only time you use a heated bed for PLA is on bare glass or Kapton tape. PLA does not have the issue of layers separating during cooling like ABS does as long as your fan is also blowing on the nozzle and filament area which it should be.

Could this issue be resolved by a guide between the geared drive wheels and the throat of the feeder tube? I've noticed that's where I get buckling with PolyFlex and I've been wondering if a guide here could fix that. Tolerances would be a little tight, but seems doable.

Definitely, I was thinking the same thing and was wondering if I could add a small plate of metal underneath both sides of the gears.  So when you feed filament through and extrude, if it ever follows the gear and starts to buckle, the filament will hit one of those plates and will continue moving in a mostly straight line.  I will look around and see what I can come up with...I have been busy with school lately.

I have succeeded in printing PLA again, this time using painters tape as glass is a little hard to stick to unless the bed is leveled perfectly, and I also use a bit of oil to get the filament going.  Using 220c extruded and 50c bed with default slic3r speed.  I also used zip-ties instead of a screw or scobo's ingenious putty mount, using one through the bottom left hole to hold it in place and another one going through the top left hole to pull it up so it does not meet parallel with the hotend.  One letdown to lowering the fan is it also moves it out a little bit, so I  can't move the mount all the way back or the fan will get crushed (or squeezed).  I keep the door open, and I took off the top lid for better airflow and easier to feed filament (I use an external spool holder that feeds through the back). 

Thanks for you guy's help, hopefully we'll get NinjaFlex going soon!

But I'm not sure, I'll keep trying and see what else comes up.