Help: How to tell if a J-head hot end is 3mm or 1.75mm?

Hi!

got my J-head in today from a far off land, China. Looks really nice. I ordered a 0.4mm nozzle for 1.75 mm filament. Looking down the barrel it looks large. how can I tell if the orifice is for 1.75mm or 3mm?

How tight are the tolerances? So a 1.75mm filament rides inside a 2mm ID Bowden tube. I just don't want to buy a bunch of 1.75 filament and later realize I have the wrong J-Head.

Thankl

Maxi

Hello,

You should be able to tell by the size of the barrel. If you can fit 3mm filament (or a 3mm drill bit) then it is a 3mm hot-end. However, it is possible to use it with 1.75 filament. The one I bought was advertised to be compatible with both filament size. The trick is to put a small piece of PTFE tubing into the barrel to reduce its diameter (the tube is on the right side of the attached picture). At first I was quite skeptic about this solution and it is probably not as good as having a proper 1.75mm barrel but I have got good results with this setup.

Just my 2 cents :-)

Cheers!

Franck