Thanks. The coop will be checked on, it's more to give them more daylight time in the morning, should we sleep-in, and to make it easier for people to help out when we're away.
Thanks Huntoon. It had occurred to me about the radius change, but that link was most useful. I've been scratching my head as to how to stop the motor when the door is up (reed switches etc) if using a DC motor (I'm new to electronics) but from that useful link, I may be best thinking about a...
Thanks. So are the units of gfcm as straight-forward as: a motor rated at 500 gfcm can lift a 500g mass with a maximum spindle/spool radius of 1cm and therefore the same motor could lift a 250g mass with a 2cm radius spool?
I must have been asleep in physics when we did torque (well it was a while ago, before I discovered beer) and am re-visiting the subject afresh. I am trying to choose a motor to lift a pop-hole door to a hen house. The motors I'm looking at have a torque rating from 400 to 1000 gf.cm, which I...