Step one is to get yourself an InStove 60L and get familiar with it. Boil some water, try different fuels, play around. Everything related to the build is downstream from this. At worst, if this is as far as you get, you'll be able to cook huge amounts of food and heat 15 gallons of water on a very small carbon-neutral fuel budget. But of course, that's not the only end goal. We're here to generate Electricity. So... step 2
Figure out your TEG budget. The FireVolt System is scalable. You can invest as little as $350 in the TEG side of a viable build with room to grow as your budget allows. In such a configuration your max output would be around 35 Watts, matched load at 9v DC, with a TEG block occupying only 1/6th of the core. The remainder of the Core walls could be water block / heat harvesters only, or simply insulated dummy panels made of 1/4" steel.
p.s. this is a no-weld build! (believe it or not) - more on that later - but going forward the instructions assume you are building a full 6-sided TEG core.
Cut 1/4" Aluminum T-beam to 10" lengths, de-burr any sharp edges. With 300 grit paper, sand the face you're mounting your TEG block to so that it is well-polished.
Mark the mounting hole drill-spots by laying the TEG block on the T-beam as a template. Drill out SIX 1/4" dia T-beam mounting holes - two will be left over for the Steel T-beam pieces. De-burr rough edges at all times.
Cut thermal interface material to full length of TEG block (12") and 4.5" wide, lay the cut piece down on the face of the aluminum T-beam piece between the mounting holes. Lay TEG block on top, sandwiching the thermal interface material evenly.
Using high shear-strength 1" long 1/4" dia hex bolts - mount the T-beams to the TEG water blocks, (Bolt head outside, Nut inside). Apply high temperature thread locker to every bolt prior to nut installation.
Cut Steel T-beams to 8 inch lengths. Mark two mounting holes for drilling, using remaining (empty) mount holes on TEG block. Drill out mounting holes to 1/4" dia.
Mount steel T-beam piece to TEG assembly with hex bolts. This completes one of the (6) TEG harvesting modules. Repeat the above instructions to produce the other 5.