I drilled 16 holes that were 1.2 mm each. I made the center tube from 1/2” copper. 2 fittings and 11 7/8” of copper worked perfect. Brewed 3 batches so far a it works great. After you solder everything, grind or file the top fitting and the basket top will go over it easily.
I have brewed 3 batches with this temperature controller and it works perfect. I brew in one pot and it is very easy to maintain mash temps. Great piece of equipment for the price.
If you fabricate a center tube from copper drill very small holes first. I have made 2 and the first one was scraped because the holes were to big. You can always make the holes bigger.
The basket is 16” tall. Should hold at least 15 lbs. of grain. Everything is there except the silicone feet and the center tube. The top has the hole and the fitting is in place at the bottom. Nice basket. I will build the center tube from copper.