Buster Brown, Rob Skinner, and Darrell Lipp stand next to a 10" Rider Engine.

Rob Skinner, Buster Brown, Bill Perleberg, and Darrell Lipp stand next to a 10" Rider Engine.

Darrell Lipp watches a 10" Rider Engine.

Richard Bouma explains his 5" Ericsson Engine.

Kelly Garcia as she starts her 6" Ericsson Engine.

Jim Knox and his 6" Rider Engine.

Jack Hargrove, Richard Bouma, and Kelly Garcia stand next to Jack's 5" Ericsson Engine.