Building a reverse helix trommel isn't just something you wack together after checking out an instructable. They are all essentially custom made and I would recomend you take some time to look over various designs, not just ours, before building. Some things just don't scale down and water is one of them. I have seen these badboys in action lots of times at gold and sapphire mines but getting this little one of mine to work in the rugged low water conditions we work it in has been a trial and error process. It is getting there however. I have included all of my trommel stuff in this instructable, from our first build and test up to the last mining season. No breakdows other than a burned out motor from water seepage. The results improve every year so follow our journey and save yourself some of our baby steps. Happy hunting!