Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz> Hi Agn Terry et al A further point or two that occured and are relevant 1) Your design permits closer spacing than axial rotor so the expansion issue can arise for this reason alone. 2) When I had trouble I was fair pushing the thing along at >5kVA Best Ted L