11-25-2012, 08:31 PM
Grain matters very much when the spring is installed and tensioned. As one of my friends found out, the grain needs to be running from stanchion to stanchion (or in this instance crossbeam to crossbeam) or the hole carrier will shatter.
That is also why placement of the beams is so critical on torsion engines. They need to provide the maximum support while allowing the optimal ammount of arm rotation. On most hobbyist reconstructions the layout of the stanchions isn't as much of an issue because they will never approach destructive force levels.
Despite my failure to provide a drawing of the tapered-drum concept, you seem to have grasped the basic idea. The ends of the draw rope would connect to the thickest part of the drum with the latch/trigger forming the apex of an inverted V attached to the arm. As the rope coils around the drum the two legs of the V converge and pull back/down at a more direct angle. Both effects should help the winch gain power as the load increases. It's essentially a variable speed winch with only one moving part.
That is also why placement of the beams is so critical on torsion engines. They need to provide the maximum support while allowing the optimal ammount of arm rotation. On most hobbyist reconstructions the layout of the stanchions isn't as much of an issue because they will never approach destructive force levels.
Despite my failure to provide a drawing of the tapered-drum concept, you seem to have grasped the basic idea. The ends of the draw rope would connect to the thickest part of the drum with the latch/trigger forming the apex of an inverted V attached to the arm. As the rope coils around the drum the two legs of the V converge and pull back/down at a more direct angle. Both effects should help the winch gain power as the load increases. It's essentially a variable speed winch with only one moving part.
P. Clodius Secundus (Randi Richert), Legio III Cyrenaica
"Caesar\'s Conquerors"
"Caesar\'s Conquerors"
