Do the black heavy-duty housings conduct?

Do these conduct? IE, if they are pressed inside a host (up against the inner walls of a host) will these housings conduct from the host into the diode and through to the case pin?

Heatsink/Laser Diode Housing for 5.6mm Diodes with Focusing Lens - Detailed item view - OdicForce Lasers Online Shop

If SO, how do you insulate/isolate a diode if using something like a Microdrive without a continuous (-) ?

I bought a whole bunch of these things from O-like.

they are anodized black, and do not conduct electrically, but conduct heat very well.
however, I wont trust them as an insulation factor, if you chip the anodizing job (which Ive done a few times with a set screw on my heatsinks) they conduct electricity just fine.

Your best bet for complete insulation of these things is to use alot of insulating thermal grease, and pressfit the modules, so no screws are there to dig into the body.
or to make sure your diode is case neutral and do not use any physical connection to the module.

I wish all diodes were case neutral.

These modules fit PERFECTLY inside C3 hosts, and the gap between where the front of these modules screw onto the body of them actually allows for the finned heatsink to extrude, while the housing body remains inside the host. The screw-on finned heatsink actually acts to hold the module on, with the slight lip of the C3 (where the glass would normally be) sandwiched between the finned heatsink and module body. Though you probably have to cut off part of the butt end of the housing so that theres room for a driver and pill, etc.

It's an awesome setup. But would be frustrating to use for a RED build, with a driver that lacked continuous (-) battery & diode pads.

I would wrap them in Kapton tape.

My 0.02

Just Use a LM317 a Resistor and a cap

Hoping to do a C3 build without extension tube, and just run it from 1x14500. So 3.6v only, which means no-go on the LM317

Aha I see said the blind man.

This is borderline insane....would it be crazy to order 2x 14250's from china, just to accomplish 7.2 V in an AA form factor, in order to use AA hosts with an LM317 circuit?
http://www.shenzhen-wholesale.com/liion-14250-36v-320mah-rechargeable-battery_sku2159.html

There's something a a bit odd about ordering expensive *microscopic* batteries, for the purpose of enabling me to use a cheaper *bigger* drivers....

It does kind of even out. I never really look at it that way tho. I decide either what battery I want or what driver, and order what ever is required to meet my goal.