Dutch windmills

[DH002F6276]

I would like to know the avererage r.p.m. of the sails on a Dutch windmill. At the moment I am building a motorised model of a mill and will gear the motor output speed to correspond so that the sails turn at a realistic speed.

[Quoi]

I am sorry I dont know but not as fast as this

http://uk.youtube.com/watch?v=QL-cRuYAxg0

[sddsddean]

If you look at this one
http://uk.youtube.com/watch?v=7qMFZcauAaM&feat ure=related
(not easy I know!) I reckon its doing about one rotation in 12 secs, so go for 5rpm and I don't think you will be far out.

[kempie]

This video (found in the related videos section of sddsddean's link)...

http://uk.youtube.com/watch?v=dII42hA2abM

...seems to indicate that the sails attain around 15+ rpm in moderately heavy winds so the estimate above matches what should be expected in more sedate conditions.