Some pretty basic stuff there - can't believe I didn't see that! Goes to show the importance of taking things slow and not jumping to conclusions! It's a small but significant force.
Cheers mate!
Dave
hey desertfox
I was thinking of that myself, it seems counter-intuitive that such a large door could operate with a small motor but the math makes sense!Thanks again for the time you've taken and for putting my mind at ease!!
Dave
Hey,
Would that inertia include the mass of the door and counterweights about the sheave, or just the sheave itself? Yes, there will be an electro-mechanical brake that can be applied against the sheave as well as a mechanical locking mechanism which will keep the door in position when fully...
Unfortunately i wont have acces to CAD drawings for a number of days. The following link provides a VERY simplified outline of the setup http://www.airportdoors.com.au/Drawings/Vertical_Lift.pdf
This is the closest match I could find qucikly! Note that a number of guide rollers will be located...
Hey desertox
Thanks for the reply! The thing that still gets me is what will occur in the (unlikely) situation that the counterweights and the door are exactly balanced? Am i right to assume that power loss via friction in the system are the only thing the motor must work against? If this is...
I'm having trouble selecting a suitable motor to lift a single leaf 1000kg door. To cut down on power costs i plan to use perfectly (or as close as i can get) balanced counterweights. The door is to be lifted 4m vertically using wire rope hung over two sheaves connected to the respective...
