I just made my CFC based on that instructable. I had never soldered copper pipe before and wanted a project to practice it before ever daring to work on a home pipe. I’ve had the gear for years and was always too chicken to try on the real thing and too lazy/cheap to practice on scrap copper. In hindsight, this is NOT the project to learn copper pipe soldering! It’s all good now, but I had to go back and fix several leaking joints. Fixing a bad solder in densely packed T joints which aren’t easily de-soldered and pulled apart was not fun. It’s all good now! Mine ended up as 6 levels of 24" length, mostly because the T’s were cheaper as a 25 count bag from where I bought them. I’d recommend getting at least 4 lengths of the 3/4" in M grade rather than L. Use for the outer 4 tubes to add some extra strength. I got a small section of M by accident because my plumbing supply store mis-filled my order and I really liked the extra solidity. I also took the authors advice and got some brass hose fittings to make a clean and tidy connection to my hoses. Looking forward to brewing again hopefully next weekend!