Single roll planar-flow melt spinning (PFMS) is a rapid solidification technique for producing thin metal sheets or ribbons. The key physics occur in a liquid metal puddle (bead) held by capillarity between the entry nozzle and a rotating metallic wheel. We present a semi-empirical analysis that (1) provides a theoretical basis for a previously reported empirical stability window, and (2) predicts an extension to the stability limits by adjusting the pressure outside the upstream meniscus relative to the pressure outside the downstream meniscus. A device capable of altering this pressure has been constructed and demonstrates extended operability. (c) 2006 Elsevier Ltd. All rights reserved.