I am not a mechanical engineer so hopefully my experience and observations will
be helpful anyhow and perhaps will be commented on by those qualified.
First and maybe most important. I once had the Fulton k2550 winch start to let
the tower tiltoverin a runaway free wheeling mode. I grapped the slowly
spinning handle to stop it so all turned out ok. It seems that the brake
mechanism requires some small load to activate the break so that if one has the
load off from the winch for a while,it can go into a free wheeling mode.
Hopefully someone will explain this.
The LM470 tiltover fixture came with the Fulton 1550 winch. When I first
tilted the tower back over, the winch screech could be heard for miles (well
blocks anyway?). At that time I had not recabled to use the pulley at the
bottom and the top of the tiltover fixture as a balance point.
Then when I considered changing the tilt mechanism to take advantage of the
balancing feature I noticed that there would not be any mechanical advantage in
the pulley system. Additionally the modification would have to be completely
correct or the tower could come crashing over on the first attempt to lower it.
I observed that my HDX572 tower tilt fixture had a double pulley at the top
and the tower itself
had a double pulley so that the mechanical advantage of the HDX572 tile
mechanism was much greater than the LM470.
I modified the LM470 to be like the HDX572 to have double pulleys and also
replaced the Fulton 1550 with the Fulton 2550 and of course
had to use a much longer cable to go around the double pulleys. It is now easy
to crank and doesn't screech at all. It takes a lot more time to do the
cranking and much of the effort is just moving my arm so I use a drill motor.
I haven't noticed any heating of the winch.
Am I correct that adding the double pulleys to make it easier to crank also
reduced the load on the winch and does reducing the load on
winch reduce the heating?
k7puc
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|