Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
Measure your mast step and search on Defender and West, see what you come up with. C25s should use 5 series blocks at the mast. The photo is of my Starwind 225, I used 3 series blocks on her.
quote:Oh, and by the way, according to my highschool geometry teacher, Mr. K, a 45° angle will result in 70% of the force of a straight vertical.
The simple sum of vector forces when the angle of application is not considered will exceed the actual applied force. The sine and cosine of 45º are equal. 100 pounds of force applied at a 45º vectors to 70# vertical and 70# horizontal.
edit: Multiplying the vectored forces by the appropriate angle functions and summing will result in 100 # of applied force, as you would expect since we're using the same values.
How does this work? Would not 100 lbs of force at 45º result in 50 lbs vertical and 50 lbs horizontal?
quote:Oh, and by the way, according to my highschool geometry teacher, Mr. K, a 45° angle will result in 70% of the force of a straight vertical.
The simple sum of vector forces when the angle of application is not considered will exceed the actual applied force. The sine and cosine of 45º are equal. 100 pounds of force applied at a 45º vectors to 70# vertical and 70# horizontal.
edit: Multiplying the vectored forces by the appropriate angle functions and summing will result in 100 # of applied force, as you would expect since we're using the same values.
How does this work? Would not 100 lbs of force at 45º result in 50 lbs vertical and 50 lbs horizontal?
quote:How does this work? Would not 100 lbs of force at 45º result in 50 lbs vertical and 50 lbs horizontal?
Correct, you must include all factors (force and angle functions) and multiply before adding. COS and SINE x the vectored forces equals 50 and 50 which sums to the applied force.
Applied Force x COS 45º, SINE 45º = Vectored Horizontal force x COS 45º + Vectored Vertical Force x SINE 45º
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
Thanks Frank, I thought that might be a risk and intended to stress test it before installing since I use 1/4" Vectran for my main halyard, a slippery line.
Dave B. aboard Pearl 1982 TR/SK/Trad. #3399 Lake Erie/Florida Panhandle
Thanks Frank, I thought that might be a risk and intended to stress test it before installing since I use 1/4" Vectran for my main halyard, a slippery line.
Vectran will definitely slip. Voice of experience.
quote:How does this work? Would not 100 lbs of force at 45º result in 50 lbs vertical and 50 lbs horizontal?
Correct, you must include all factors (force and angle functions) and multiply before adding. COS and SINE x the vectored forces equals 50 and 50 which sums to the applied force.
Applied Force x COS 45º, SINE 45º = Vectored Horizontal force x COS 45º + Vectored Vertical Force x SINE 45º
Anyone else break the hound on the boomvang? Mine snapped after 25 years while out this past week. Was just going to replace it with a new hound (~$15) and then re-screw it back in. But wondered if there was a better way.
Dlucier solved this problem a while back
Schaefer Marine part 90-08, about $40, 3.75" wide by 4" deep. This is on a C-25 Tall Rig (so the mast is a bit bigger than a standard one). You need a 5" 3/8-16 bolt (and a hacksaw to trim that extra bolt length) to avoid having any threads in the mast.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.