Inboard boatlift cables still getting slack...
Please try to help further diagnose what is causing this. There is more
information this time to work with.We have an 8,000# Magnum 'HD' piling-mount cradle boat lift with what I
think appears to be a slight "bunk buoyancy" problem. When the lift is down
in the water near the bottom of its travel with no boat weight on it yet and
I start to bring the lift up, the cables on both inboard sheaves (pulleys)
start to get a bit slack (especially bad on the right inboard side) while
the outboard cables stay nice and taught. As a result, the inboard (1/4"
cables) don't always windup on the winder spool without a bit of
"criss-cross" unless I keep some downward pressure on the PVC upright pipes.
We operate in saltwater and have a pontoon boat on the lift with 3"x12"x20'
wooden bunks. I experimented once while the boat was away from the lift just to see what
was going on and the problem definitely goes away the moment the wooden
bunks get above the waterline. The inboard cables get tight again and
everything spools fine. Checked by lowering the beams down just to the waterline, the lift is very
nearly level (only one inch higher one the inboard side) from an
inboard/outboard perspective. I have checked and none of the sheaves are
stuck. I added 80 pounds of weight nearest the pulley/sheave on the right
inboard side which has "band-aided" the problem some, but has not "cured"
the problem. I am seeking the CAUSE of this problem. Two Questions: 1. Why do just the inboard cables get slack? 2. Why does
just primarily the right-hand inboard cable get even more slack than the
left inboard-cable?? Your help appreciated. Chuck Lift installation diagram for reference:
http://www.lunmar.com/commerce/assets/instal_guide/maghd-1.htm |
