New Products Flash Sale
Thread Tools
Old Yesterday, 10:34 AM
poltergeist is online now
Find More Posts by poltergeist
Registered User
poltergeist's Avatar
Pomona, CA
Joined Apr 2007
776 Posts
Hi Dunc,

I'm by no means an expert on drum type winches, but I think most setups use some way to keep the line on the drum taut. The two most common setups are described here
http://www.theamya.org/boats/us1m/pdf/us1mpt4.pdf on page 59

I think without a "continuous loop" or with elastic to keep tension on the sheets when they're eased, it's pretty easy to get tangles.

Kevin
poltergeist is online now Find More Posts by poltergeist
Last edited by poltergeist; Yesterday at 05:21 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Yesterday, 12:36 PM
Dunc Newt is offline
Find More Posts by Dunc Newt
Building a Nottingham J boat
Dunc Newt's Avatar
United States, FL, Beverly Hills
Joined Aug 2014
18 Posts
Mine is a continuous loop with lots of guides to keep the incoming line aligned to the two levels of the drum. Sitting my desk it works without an elastic, but I might add one for good measure - I'm just concerned the elastic will lose it's stretchiness over time.
Dunc Newt is offline Find More Posts by Dunc Newt
Last edited by Dunc Newt; Yesterday at 02:39 PM.
Reply With Quote
Old Yesterday, 06:07 PM
poltergeist is online now
Find More Posts by poltergeist
Registered User
poltergeist's Avatar
Pomona, CA
Joined Apr 2007
776 Posts
Dunc,

Thanks, those photos are much more clear to me!!! Guess I should've read your description more carefully and I might've caught on sooner. Looks good! I think I've heard of folks using a relatively strong spring in the continuous loop to keep the line taut....but again, I'm no expert.

Can't wait to see her sailing!!!

Kevin
poltergeist is online now Find More Posts by poltergeist
Reply With Quote
Old Yesterday, 07:37 PM
FoamCrusher is offline
Find More Posts by FoamCrusher
If it floats....sail it!
FoamCrusher's Avatar
Elk Grove, CA
Joined Sep 2002
4,297 Posts
Dunc:

Your trolley system is certainly industrial grade, but it will still need some kind of tensioning device - a spring, elastic thread, rubber bands or spring tensioning drum - to keep the line tight. Not all of those drawings in the US1M Construction Guide that Kevin linked to show them, but there has to be something there so the line does not slip on the drum as it slowly stretches. Most systems I have seen use a stainless steel spring on the rewind side of the ring to which the sheets are attached. McMaster-Carr carries them and I am told that any of the 1" long springs on this page : http://www.mcmaster.com/#extension-springs/=xcsara should work.

The other issue that Kevin pointed out is that since the trolley will pull in both sheets by the same linear amount, it is critical to be able to "tune" the system for the correct amount of swing for both booms, from close-hauled to full out.

Since the main boom swings from about 5 degrees off the centerline to about 90 degrees (usually a bit less since the boom hits the lower shroud - you have to test this to see what it is on your boat)(~80 degrees net) and the jib boom swings from about 15 degrees to 90 degrees (75 degrees net) , the travel amounts are not the same and you must adjust by moving one of the sheet attachment points on one of the booms and or the deck fairlead locations until the take up of equal amount of line give you the swing you need for each spar. What you use to adjust the close hauled position - bowsies, hooks or cleats, only changes the take up by a small amount and is generally not enough to get the swings to be what you want.

Assuming your deck fairleads are already located, the only real way to tell is to set up one of the boom attachment points so it is movable - moving it closer to the pivot point (gooseneck pivot for the main and the boom to deck attachment point on the jib) decreases the line take up and moving out increase it.

You do this after you have the deck on, the mast and shrouds up and in their normal location fore/aft, the trolley in place and all the sheets run. You will probably only need about 1/2" to 3/4" movement on the boom to dial it in.

I am doing the preliminary set up for a drum system right now with a US1M I am building that will be using an RMG winch that has a spring loaded drum. The difference will be that I will not be using a rod type trolley, but fixed block locations on the deck as in this drawing: https://www.rmgsailwinch.com.au/rmg/...n-and-Use.html However, I want the main fairlead post to be right under the main boom attachment point and the jib fairlead to about 1' aft of the jib attachment point for best sail trim so it is taking quite a bit of fiddling before drilling the fairlead locations to get what I want and have the swings correct.

Steve
FoamCrusher is offline Find More Posts by FoamCrusher
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Anybody here have a Canterbury J sailboat? Ed Crowell Sailboats 62 Nov 11, 2014 02:52 PM
Discussion OFFICIAL KDS 450s /sv THREAD / HELP - DISCUSSION - GENERAL - #for all kds needs d1cky_kds Electric Heli Talk 20 Mar 27, 2014 08:28 AM
Build Log J-Power A-10 build, mods, general discussion thread gunracer Foamy EDFs 199 Jul 29, 2012 12:49 PM