Direct drive washing machine motors like from Fisher and Paykel seem to work well. https://www.thebackshed.com/windmill/Contents.asp#3 https://www.thebackshed.

Direct drive washing machine motors like from Fisher and Paykel seem to work well. https://www.thebackshed.com/windmill/Contents.asp#3 https://www.thebackshed.com/windmill/Contents.asp#3 has some details, and in the forums there.