Closed Loops (New design)

[sphelps]

For OMs I didn't find the smaller version to work that well. The drum was magnetically driven and as a result would get stuck often from something as simple as couple grains of sand. It required frequent cleaning to keep it operational. Now the larger 4 way has a direct shaft driven drum which seems to keep going no matter what. For these reasons I would personally only go with a shaft driven OM, not magnetic.