Sometimes, it’s the machine you don’t sell that wins you business.

Equipped with quick-change tooling, this bowl can feed cartridges with the open end leading or trailing. Note how the tooling to feed the cartridges in the opposite direction is stored on the bowl itself. Photo courtesy Custom Feeder Co.

That was the case for Mike Stamm, general manager of Custom Feeder Co. (Rockford, IL). Recently, an ammunition manufacturer contacted Stamm to build two vibratory bowls to feed 9 mm pistol cartridges at a rate of 120 parts per minute.

One bowl needed to feed the cartridges with the open end trailing, so an ejector groove could be machined around the cartridge body. The other bowl had to feed the cartridges with the open end leading, so the parts could be cut to length. Since both operations would be performed on the same machine, a complicated slide mechanism would switch from one bowl to the other.

Stamm had a better idea. Why not build one bowl to handle both jobs? Stamm and his team built a bowl with an inside track that feeds the cartridges upright, with the open end up. As the track winds to the outside of the bowl, it encounters a set of quick-change tooling that tips the cartridges forward or backward. Two bolts hold the tooling in place.

“We avoid adjustable tooling whenever possible, because we don’t want operators to dial in any parameters,” says Stamm.

Changeover takes less than two minutes, and the bowl feeds 160 cartridges per minute. In another bit of clever engineering, the opposite set of tooling is stored on the bowl itself, so operators never waste time looking for it.

For more information, call 815-654-2444 or visit

Editor’s note: This is the first installment of a regular series profiling parts feeders for automated assembly systems. Whether it’s a vibratory bowl, a tray feeder or a flexible robotic system, if you’ve solved a parts-feeding challenge, we’d like to hear about it. Send an e-mail to John Sprovieri, editor of ASSEMBLY, at, or call 630-694-4012.