They spent $3,000 on a MakerBot Replicator 2 and made a promise to each other: If they could get the 3-D printer to pay for itself in one month by completing orders, they would quit their jobs.
他们花了3000美金买了台MakerBot Replicator 2(3D打印设备),并且许下誓言:如果他们的3D打印机能在一个月之内赚回本,他们就辞职,专心做这个事。