Something like this should work: http://amzn.com/B00NVBX34U

If you were on repetier, why enlarge the nozzle anyway? Speed?

For me, speed and overhangs. I find that the thinner extrusion sags more on bridges.

So if you want to do this correctly. Get light sandpaper, sand it very lightly and make sure the nozzle tip is FLAT, it's easy to sand poorly and have an angle in the nozzle tip. Then use a .4mm wire and feed it through. You shouldn't have to force the wire through. If it requires force, sand the nozzle a little more until the wire doesn't need force to feed it through.

I roughly extended the nozzle tip size and it is working great. Be careful with the nozzle tip, it is brass and is very thin near the tip so its easy to puncture a larger hole than intended.

Just curious, how did you enlarge the hole? Did you use the Pin method that was suggested?

Here is what I tried:

Moving the PCB board from in the nozzle to the carriage: Made No difference.
Replacing Thermistor: No Difference
Replacing Heating Block: No Difference

I then decided to put on the replacement nozzle, but also decided to move the PCB to the carriage.
Before I re:installed the new nozzle, I retried the original (with orignal Thermistor and Heater Core), but using the new nozzles PCB: Success

I ran a 6 hour print with no issues: Will be running more to see if this was a fluke, but it looks like it may have been the PCB board in the original nozzle.

That being said: you cannot buy these from XYZ. There are 6 pins in, and 3 devices : Fan, Thermistor, Filament Detector. I am going to see if I can find which pin goes to which (unless someone already knows) and if it adds any resistance to the Thermistor (i read somewhere that the 1.0 adds a bit of resistance so we cant use known therm tables, not sure if this is done on the mainboard, or in the PCB).

I am still going to do the E3Dv6 Conversion because I want to print with other materials, and this has given me an excuse to buy the Hot End.

I also printed some things in .25mm nozzle diameter (in ABS) and they turned out fantastic.

I also purchased a E3D v6 and am going to install it sometimes this week or next weekend and keep the .25mm stock nozzle around as a backup.

Also thinking about it, this nozzle should work with PLA. I wonder if the smaller diameter was the change they made for this. Thinner = faster cooling ... means the lack of extra cooling fans may not matter. This is all speculation at this point.

No. The feed neck will be the same size as it still accepts 1.75mm filament, having a .15mm smaller nozzle definitely would not reduce cooling, rather make it harder for the extruder to push the filament down which may lead to the extruder slipping

That makes sense about the PLA though.

If you decide to switch to a E3D, I would be glad to purchase your old (new) extruder if you decide to get rid of it.

I was serious about using a pin...

That might work, but I would rather not do this. If the bore is .25mm through the nozzle it would be best to use a drill bit to bore it out more.

Instead of doing this I may just keep it at .25mm and get an E3D v6.

Also thinking about it, this nozzle should work with PLA. I wonder if the smaller diameter was the change they made for this. Thinner = faster cooling ... means the lack of extra cooling fans may not matter. This is all speculation at this point.

Since I use Rep.92, I don't think they are going to help out much.

It makes me wonder if the newest firmware detects the nozzle differently? (Say from the circuit board?)

There's about a 20% die swell coming out of the hot end. If you extrude into air, a .3mm nozzle should produce a .36mm thread. If you're free air extrusion averages .31mm, your nozzle size is closer to .25mm.

Thanks for the info,

I'll also try .25mm in my settings when I am done. Slic3r yells at me if I try to have a height that is larger than my nozzle diameter... so it looks like I'll have to print at .25 or smaller (Not happy about this)

I have also contacted XYZ about this to see if they know anything about this (not holding my breath though)