I've been working on a concentrate vaporizer design that is easier on my abused and aging lungs than my past two designs. I've made good progress and am currently awaiting some glass parts that I'm having built locally by Oracle Glass. I ordered two pieces, a #14 borosilicate taper to 8.5mm hose barb, and a #14 borosilicate taper to mouthpiece.
I was blown away by the $20 bid after working with a scientific glass manufacturer for years and paying those prices. Also, for the short deliver, with a promised delivery of this week.
Besides a couple bubble chambers to cool down the vapors and strip off some of the harsh terpenes, the key is the electrically heated 20mm Diamond Knot borosilicate nail. It has a super small bowl, which limits surface area, allowing you to string out the vaporization of a single dab to multiple draws.
After loading the dab, I place a carb cap over the nail and draw, which drops the atmospheric pressure in the bowl, causing the boiling point to drop and more rapid vaporization to occur. i get about five smaller hits from a dab instead of one or two large ones.
I'll post pictures of the prototype test sled here and a blurb in the concentrates thread, when I have all the final parts and have tested the complete system rather than just parts.