Announcements
New Discussions
Best spinnaker halyard line material?
by '81 Hobie 16 Lac Leman. 03/31/24 10:31 AM
Previous Thread
Next Thread
Print Thread
Rate Thread
Hop To
Mast Rotation Stops #24156
09/13/03 01:25 PM
09/13/03 01:25 PM
Joined: Aug 2003
Posts: 51
Queensland, Australia
Philthy Offline OP
journeyman
Philthy  Offline OP
journeyman

Joined: Aug 2003
Posts: 51
Queensland, Australia
Hello,
I'm looking for suggestions on how much mast rotation is needed on a H16. My boat is fairly new and I know alot of people cut away the rotation stops to allow more rotation. I've read that over rotation is better than under rotation, I've also been told less rotation is better for increasing power. As my total crew weight is about 160 kgs (60lb over minimum for our US friends) so do I need more or less. Any suggestions appreciated
Phil

-- Have You Seen This? --
Re: Mast Rotation Stops [Re: Philthy] #24157
09/15/03 11:01 PM
09/15/03 11:01 PM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
What your looking for is a clean,smooth transistion from the mast to the sail.

On the beach sheet your main like your going to weather. Make sure the mast is rotated fully. Look at the sail-mast junction. It should transistion smoothly. If it looks under rotated, file the stops until sail-mast junction looks perfect.

This will give you max. power and the least drag. Different sails may need different angles of rotation. So don't go crazy filing.


Have Fun
Re: Mast Rotation Stops [Re: Philthy] #24158
09/16/03 02:25 PM
09/16/03 02:25 PM
Joined: Jun 2001
Posts: 97
Bogie Offline
journeyman
Bogie  Offline
journeyman

Joined: Jun 2001
Posts: 97

The mast-rotation tips you've read seems to be pretty good info. However, a few details would be helpful. The mast rotation effects mast-bend which in turn effects sail shape which affects speed and power. The mast is just simply easier to bend at the minor axis by a combination of rotation and main sheet tension. This tends to produce a flatter sail shape which is good for speed, pointing, etc.

So, filings the stops tends to produce a bendy mast and a flatter sail shape. Some folks build up the stops to inhibit rotation and mast bending, in order to keep a full sail shape. Heavier crews are generally the ones concerned with keeping a full sail shape. So, in your case (60lbs over) minimum. The stock rotation seems about right.

There used to be a third-party product, that resembled an insert to reduce or build up the stops. I haven't heard much about that product lately, and don't know if it's still available. If you know someone that can do aluminum welding then you could experiment and build up the stops if you over-file.

Re: Mast Rotation Stops [Re: Philthy] #24159
09/16/03 08:49 PM
09/16/03 08:49 PM
Joined: Jan 2002
Posts: 70
Sodus NY
h16bill Offline
journeyman
h16bill  Offline
journeyman

Joined: Jan 2002
Posts: 70
Sodus NY
New stops right from the factory seem to be the fastest. Don't cut them. Back when the boats were raked forward that might have worked but its old news now. The 2003 sails are set up so you can rake back even further. Raking back depowers some but allows you to point higher. So instead of over rotating the mast to depower just rake it back for a better effect.

cheers
Bill

Re: Mast Rotation Stops [Re: Philthy] #24160
09/17/03 07:42 AM
09/17/03 07:42 AM
Joined: Jul 2001
Posts: 106
West Texas
Hobie Dave Offline
member
Hobie Dave  Offline
member

Joined: Jul 2001
Posts: 106
West Texas
We sail about 80 to 85 pounds overweight. I have cut my rotation stops and built them back up. We do better with less rotation. My mast rotates to where it points towards the shroud wires.

David

Re: Mast Rotation Stops [Re: Hobie Dave] #24161
09/19/03 06:39 AM
09/19/03 06:39 AM
Joined: Aug 2003
Posts: 51
Queensland, Australia
Philthy Offline OP
journeyman
Philthy  Offline OP
journeyman

Joined: Aug 2003
Posts: 51
Queensland, Australia
Thanks all for your replies, the sail is new and apparently the newer ones are fuller than previous which should help with the extra kilos, however the sail / mast transition looks like it need smoothing out unless the mainsheet is block to block. I'm guesing but the flatness that you get from sheeting hard helps when the winds up and should help further flatten the sail if I increase the rotation. Likewise when its light to moderate and the sail is lightly sheeted and fuller the rotation still needs to be increased to correct the mast / sail transition.
Maybe I'll just attack it lightly and see what happens !

Thanks Phil

Re: Mast Rotation Stops [Re: Philthy] #24162
09/20/03 12:13 PM
09/20/03 12:13 PM
Joined: Jul 2002
Posts: 170
Australia
Jules_topcat Offline
member
Jules_topcat  Offline
member

Joined: Jul 2002
Posts: 170
Australia
Ok heres from what i know because i had the sme problem. A friend who sails a hobie 17 who is very very good and i would say can sail the a hobie 17 faster than any other hobie 17 sailor in Australia. As for the hobie 17 the hobie 16 you cant choose where you want the mast to sit unless you fine or put a mast stopper. He told me the more mast rotation you have the more power normally. The only problem is in heavy winds you want your sail full and flat. To do so you really want the mast as close to the center as possible but then you have a problem because you want to make it rotate more. I own a 1986 Hobie 16 and i had old sails and it wouldn't point what so ever and the mast rotated very easily and was sitting way past where the normal hobie 16 sits. When i went to a regatta i was getting killed in hight so i went out and bought a new sail and a new mast stopper. I raked my mast again because the 2 sails raked differently and im pointing alot higher and have alot more power.

In all this i noticed i was paying to much to the mast raking and mast rotation. Where ever your mast sits leave it because they set it for all conditions. If you sail in an area with no wind then maybe i would file it back but other than that i wouldn't worry. you get more power from new sails and rigging your boat properly!!

Have fun and just get out there and sail!!


Jules_topcat

Moderated by  Damon Linkous 

Search

Who's Online Now
0 registered members (), 736 guests, and 110 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Darryl, zorro, CraigJ, PaulEddo2, AUS180
8150 Registered Users
Top Posters(30 Days)
Forum Statistics
Forums26
Topics22,405
Posts267,056
Members8,150
Most Online2,167
Dec 19th, 2022
--Advertisement--
Powered by UBB.threads™ PHP Forum Software 7.7.1