Well, I have a long way to go on my Repstrap, but I finally started machining a J-Head. So far, I’ve only completed the threaded heat chamber. My first attempt was less than stellar, but my second attempt came out much better. It still may not print well, but it looks pretty 
I’m not sure how up-to-date everything is, but: http://reprap.org/wiki/J-Head#Version_4
Looks great. I sure miss my mill and lathe.
@Wayne_Friedt Ya, this stuff is a lot smaller, and higher tolerance, than I’m used to. I had to tighten the ole lathe before I was able to machine an accurate part 
What did you do differently from the first to the second attempt?
Aside from just learning the best order of operations, I used better, sharper, tools, re-centered the tailstock, tightened all the gibs, and put my glasses on
Why are you making the v4? The MKV is much easier, smaller, and performs the same with fewer operations.
I’m actually making the MKVI-B J-Head, The “V4.x” is just the nozzle version, which is identical to the 5, but brass. I plan on making an aluminum version as well.
Aluminum doesn’t retain the heat well enough. Brass is more thermally stable, as you may soon find out 