I agree with Andinista and have recently added another block to my 8:1(even after reading this thread).
Sure i can now probably apply more force, but i don't want to. my goal was to need less strength to sheet to the same amount (i have shoulder issues).
Also i have a hard time believing the sheeting forces are the same on an f18 and n20... but i am not an engineer
Upgraded
an 8:1 system to a 9:1, but the existing block hardware was not beefy enough to handle the loads, found out the hard way 3 days into Tybee.
This statement suggests that an increase in purchase means necessarily an increase in max load applied. Is that really true? Don't we want to actually lower the pull to acheive similar results? Therefore more pulleys should mean lower load and not higher, except at the connections in both ends, where the total load is applied.
That's assuming that the goal is to distribute the load rather than apply more total tension. Maybe I'm wrong there.. Still, we are talking about a 10 to 15% increase in purchase, which comes with a decrease in overall efficiency because of the higher friction, therefore, the total tension is increeased in less than that. Would that be enough of an increment to break the blocks? If not rearranging blocks too differently (like the single block suggested in the first post) I think it shoudn't
Did you notice the difference?
(I'm feeling guilty about spending that money in blocks rather than with my wife.. I need some reassurance..)
I haven't actually tried mine but went to the 8:1 in the belief that I'm undersheeting while sailing alone.
I've little doubt the money is well spent.
I ordered the quad blocks by the way. The single block idea was probably good but was about half the price, not cheap enough for a probably compromised solution. (That's how I convinced myself anyway..)
I did the same, for much the same reason. A lot of F16s are using the system and I wanted to keep the boat as current as reasonably possible.
Here is how I intend to route the line, it seems to be the option with less crossings and with a more even distribution of the line segments speeds:
![[Linked Image]](http://www.catsailor.com/forums/ubbthreads.php?ubb=download&Number=12471&filename=2.JPG)
What do you think?
http:/
I ran mine like the other example, though I came up with it through trial and error.
I could not make fine adjustments with 7:1, to sheet hard I'd actually lift my butt off the hull, that resulted in steering all over the place.
What do you think?
Whoa! cats cradle! The top block needs to be at 90 degrees to the triple
(I'm feeling guilty about spending that money in blocks rather than with my wife.. I need some reassurance..)
i can't say i felt much difference but my shoulders are less sore than usual.
HM is right.
There is a much better way to reeve than the Harken diagram.
PM for a pic
Sure i can now probably apply more force, but i don't want to. my goal was to need less strength to sheet to the same amount (i have shoulder issues).
Also i have a hard time believing the sheeting forces are the same on an f18 and n20... but i am not an engineer
Upgraded
an 8:1 system to a 9:1, but the existing block hardware was not beefy enough to handle the loads, found out the hard way 3 days into Tybee.
This statement suggests that an increase in purchase means necessarily an increase in max load applied. Is that really true? Don't we want to actually lower the pull to acheive similar results? Therefore more pulleys should mean lower load and not higher, except at the connections in both ends, where the total load is applied.
That's assuming that the goal is to distribute the load rather than apply more total tension. Maybe I'm wrong there.. Still, we are talking about a 10 to 15% increase in purchase, which comes with a decrease in overall efficiency because of the higher friction, therefore, the total tension is increeased in less than that. Would that be enough of an increment to break the blocks? If not rearranging blocks too differently (like the single block suggested in the first post) I think it shoudn't
Nacra 20 has a softer, bendier, mast so you have to be careful not to oversheet more so than the F18...but, we sheet them similarly.
Upgraded
an 8:1 system to a 9:1, but the existing block hardware was not beefy enough to handle the loads, found out the hard way 3 days into Tybee.
If you added a point of purchase you decreased the load on the hardware (blocks)itself. I think you were just using some old busted-butt, brokedown, shite. i've used an 8:1 modded to 9:1 since it was allowed by class rules ,at least 4 Tybees worth.
Nacra 20 has a softer, bendier, mast so you have to be careful not to oversheet more so than the F18...but, we sheet them similarly.
? I thought it was easier to oversheet Rob's wildcat than Forrest's N20 - both in 18+ conditions... maybe I was just seeing things? Or are you referring to the N20 with aluminum mast? I never considered that carbon mast particularly
bendy
???
Jake,
Can you oversheet the N20 to the point of breaking the mast? Using the OEM 8:1.
Forrest
Can you oversheet the N20 to the point of breaking the mast? Using the OEM 8:1.
Forrest
Not with a wuss like Stank pulling strings you can't! <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />
+1 on that Karl!
I don't recall anyone ever breaking a mast from oversheeting a main (on any boat except maybe an H16 before they started raking the masts back). Even with the 10:1 setups?
Only N20 masts I've heard that broke were stuffing into a wave with spinnaker up (Mike H), letting the mainsheet go with the spin up, and getting tossed around at Jensen Beach during the T500. Maybe there are more out there?
Karl,
Don't let him fool you....when others ain't looking, he begs me to pull them. Plus, I'm expected to keep the waves off of him.....was that skipper or slave driver?
Can you oversheet the N20 to the point of breaking the mast? Using the OEM 8:1.
Forrest
I doubt it. In big air upuwind and sheeted properly, the I20 mast looks like a wind surfer rig to me. After sailing F18 for a while and coming back to the 20, I had to get used to seeing that much bend in the rig. I'm not sure you could do any damage even with 10:1 though.
I've got a 10:1 on my N20 and I crank the hell out of it with absolutely no concern about my stick breaking.
So with a 10:1, you crank your stick and don't break it?
Typical 20 drivers, always inappropriately cranking their stick. Speed tip, less cranking more sailing.
But they can say
My stick is bigger than your stick
.
If Grand Pa can find the stick!
There is a much better way to reeve than the Harken diagram.
PM for a pic
Hi CCAT, i have PM'ed you 2x trying to see that diagram. Can you please send or post it?
Thanks
We sail with 10:1 as well on the I20 and can really crank it. Amazing how much it flattens the sail along with the downhaul. No problem on the mast for us.
I've run < 2" separation block to block on the N20 with a 10:1 purchase, the mast barely winces.