2-6" Flexible Gas Conduit (about 3/4" in diameter)
2x 1/4-20x1" Hex Bolt
1/4-20 Long Nut
Metal Saw (Sawzall or hacksaw)
1/4-20 Tap/Drill Set
UPDATE: Just came across this design on the web, looks to be a bit sturdier though maybe 10x the weight. Either way, another option!
Step 1: Prep Conduit
Pretty easy step here, cut the conduit to size and file any rough edges that may remain. I used about 4-inches since I wanted to be able to bend the tripod 90-degrees for portrait shots. As a note, I found this length to be a bit long for super-stable shots, as the weight of the camera "bounced" if you weren't careful. If you're using a heavy camera definitely go shorter! To dampen this bouncing, you might find it useful to fill the conduit with something like sand . . . but that of course adds weight!
Step 2: Epoxy Top Bolt
Once the bolt fits in the conduit, figure out how much thread you need to stick out in order to firmly connect your camera. Don't forget to do your test fit with a 1/4" washer in place.
Once you feel you have the correct amount of thread sticking out, epoxy the bolt and washer in place. I placed a dab of epoxy, let it dry, then filled the rest of the cavity in order to avoid messiness. Of course later I realized that I should've just plugged the conduit beneath the bolt (see next step)
Step 3: Epoxy Bottom Nut
The reason I decided to use a nut on this side instead of another hex bolt was so that I could screw the camera directly into the trekking pole (to use as a monopod) I I wanted to.
Step 4: Drill and Tap Trekking Pole
Next, tap and drill a 1/4-20 hole in the top of the trekking pole. Make sure you've got enough thickness for at least three threads! If not, you could easily end up stripping the plastic threads.
Once you've got your hole tapped, reattach your wrist-straps and connect the flexible conduit tube you just made!
To keep things light, I just tied the tapped trekking pole and two others together to create the three legs. This worked surprisingly well and was even stable enough for night shots!