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Mast rotation 4 boomless cats necessary 4 racing? #138211
03/29/08 12:25 PM
03/29/08 12:25 PM
Joined: Sep 2007
Posts: 531
Lake Murray SC
FasterDamnit Offline OP
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FasterDamnit  Offline OP
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Lake Murray SC
Your thoughts, please. Is a forced rotation setup a big benefit w/ a boomless main. G-Cat 5.7 rig.

Gracias.


Race cheap, race faster, Damnit!

E-Scow
24' ULDB

18HT hulls plus Gcat 5.7 rig = 18GT!
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Re: Mast rotation 4 boomless cats necessary 4 racing? [Re: FasterDamnit] #138212
03/29/08 12:28 PM
03/29/08 12:28 PM
Joined: Jun 2002
Posts: 806
Toronto, Ontario
pitchpoledave Offline
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Toronto, Ontario
For downwind, yes definitely.

Re: Mast rotation 4 boomless cats necessary 4 racing? [Re: pitchpoledave] #138213
03/29/08 12:32 PM
03/29/08 12:32 PM
Joined: Aug 2007
Posts: 93
virginia beach, VA
dsltrc Offline
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virginia beach, VA
on my supercat 19 i use a mast limiter.... and down wind i use it to rotate the mast more.....


Jason DiPietro supercat 19
Re: Mast rotation 4 boomless cats necessary 4 racing? [Re: FasterDamnit] #138214
03/29/08 12:39 PM
03/29/08 12:39 PM
Joined: Jun 2001
Posts: 1,459
Annapolis,MD
Keith Offline
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Keith  Offline
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Annapolis,MD
Quote
Your thoughts, please. Is a forced rotation setup a big benefit w/ a boomless main. G-Cat 5.7 rig.

Gracias.


Definitely a plus on boomless Nacras up and downwind.

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: pitchpoledave] #138215
03/29/08 12:41 PM
03/29/08 12:41 PM
Joined: Sep 2007
Posts: 531
Lake Murray SC
FasterDamnit Offline OP
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For downwind, yes definitely.


How about w/ a spin? The traveller is not out very far on spin boats off the wind.

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: FasterDamnit] #138216
03/29/08 01:51 PM
03/29/08 01:51 PM
Joined: Aug 2005
Posts: 2,921
Michigan
PTP Offline
Carpal Tunnel
PTP  Offline
Carpal Tunnel

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Michigan
I have trouble conceptualizing (?) the issue of mast rotation downwind because people set it as if the wind were really coming from the side when, especially with the spin, it actually isn't by the time you have apparent wind. So, according to wind flow, it should just be a little out from where it is upwind but everyone seems to blow it completely and let it go almost 90 degrees. Who knows though, just thoughts...

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: PTP] #138217
03/29/08 02:17 PM
03/29/08 02:17 PM
Joined: Mar 2008
Posts: 57
Minneapolis
Mpls_Nacra Offline
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Minneapolis
Could someone post some photos of the system. I am interested in installing one on my N 5.8.


Dave Foster
Minneapolis
Nacra F16
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: FasterDamnit] #138218
03/29/08 02:53 PM
03/29/08 02:53 PM
Joined: Jul 2006
Posts: 1,147
Bay of Islands, NZ
W
warbird Offline
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Bay of Islands, NZ
Nacra 14sq the rotation becomes needed downwind in the light. Once the wind is up enough to force it around you are better off concentrating on not making mistakes and keeping your head out of the boat.
Up wind the in-haul is what sets the mast rotation so do not give it a thought as far as the spanner is concerned. Get the in-haul and main tension right and you are sweet. Again, less mistakes and mucking about inboard is faster.

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: FasterDamnit] #138219
03/29/08 03:38 PM
03/29/08 03:38 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
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South Carolina
Quote
Quote
For downwind, yes definitely.


How about w/ a spin? The traveller is not out very far on spin boats off the wind.


Actually, you MUST have it with a spin. Otherwise, you can't control the mast rotation and it could rotate to weird angles and cause breakage. On a boat with a boom, that can force positive rotation with sheet pressure, it's not necessary to lock in the mast rotation.


Jake Kohl
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: Jake] #138220
03/29/08 03:43 PM
03/29/08 03:43 PM
Joined: Sep 2007
Posts: 531
Lake Murray SC
FasterDamnit Offline OP
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Thanks. Any preference which way to mount the rotator? facing aft or forward?


Race cheap, race faster, Damnit!

E-Scow
24' ULDB

18HT hulls plus Gcat 5.7 rig = 18GT!
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: FasterDamnit] #138221
03/29/08 05:25 PM
03/29/08 05:25 PM
Joined: Aug 2006
Posts: 297
R
rexdenton Offline
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rexdenton  Offline
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Quote
Thanks. Any preference which way to mount the rotator? facing aft or forward?

I had a 5.5 with a spin. Mast rotator worked fine, but you have to watch it and limit downward movement, as it could get caught on the spi pole.


Nacra F18 #856
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: rexdenton] #138222
03/29/08 05:35 PM
03/29/08 05:35 PM
Joined: Sep 2001
Posts: 756
Newport, RI
wildtsail Offline
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Newport, RI
An eyestrap about a foot above the mast rotator on the front of the mast with a rope or wire leading down to both corners of the rotator arm to hold the rotator up will solve that problem.

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: wildtsail] #138223
03/29/08 07:39 PM
03/29/08 07:39 PM
Joined: Aug 2006
Posts: 297
R
rexdenton Offline
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yep, but I used a bungee


Nacra F18 #856
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: Mpls_Nacra] #138224
03/31/08 11:47 PM
03/31/08 11:47 PM
Joined: May 2002
Posts: 217
J
jcasto1 Offline
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J

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Posts: 217
I have rotation-inducing hardware on both my 5.7 and 5.5uni, generally considered mandatory for downwind control of sail shape on boomless rigs. I'll take a picture wednesday & post.
I mount the rotator facing forward. And you must have lines to keep jib sheets from tangling.
Cleat position for rotator should be where you can easily release just before a jibe. I have a continuous line, so I can cleat & uncleat from either side, using H240 swivel cleats and bullseye fairleads. You'll need a special mounting pad to mount the swivel cleat on the NACRA round beam.


Jim Casto
NACRA 5.5 & NACRA 5.7
Austin TX
Lake Travis
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: jcasto1] #138225
04/01/08 09:45 AM
04/01/08 09:45 AM
Joined: Jun 2003
Posts: 712
mikekrantz Offline
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I made my own contoured mounting pads by cutting the material out with a hole saw. Then I taped 60 grit to the beam, and rubbed the pad back and forth. In just a couple of minutes the base pad contour matched the beam's contour.

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: mikekrantz] #138226
04/01/08 09:34 PM
04/01/08 09:34 PM
Joined: May 2002
Posts: 217
J
jcasto1 Offline
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cool idea, thanks.

I recently took my swivel cleat & pads off to service the old swivel cleat, and noticed corrosion on the aluminum beam under the pad. Any ideas on how to avoid corrosion like this? I'm used to seeing corrosion where SS screws go into Aluminum, but this was a 2" diameter circle that will eventually eat through my beam!
What about cleaning it before mounting, then using silicone or something to seal it and keep salt water out?


Jim Casto
NACRA 5.5 & NACRA 5.7
Austin TX
Lake Travis
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: jcasto1] #138227
04/01/08 09:57 PM
04/01/08 09:57 PM
Joined: Mar 2004
Posts: 80
West Virginia
Soapysails Offline
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Soapysails  Offline
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Posts: 80
West Virginia
A simple and cheap way to stop this problem..clean the effected area, apply a thin film of "Calsium Starite" a polimer based grease.(clear lithium will work too) These soap based greases resist water and will stay put forever ! clean around the area after re-assemble with MEK or 111 tricloro.

Find a DuBois Chemical or Johnson-Diversey rep in your area..he or she will be happy to give you a small sample (-1oz.)if that fails, I will mail you some myself..

Re: Mast rotation 4 boomless cats necessary 4 raci [Re: Soapysails] #138228
04/02/08 08:15 AM
04/02/08 08:15 AM
Joined: Jun 2004
Posts: 1,479
Thailand
Buccaneer Offline
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Buccaneer  Offline
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Thailand
Another significant advantage (almost as important as the increase in speed!) is the Mast rotation limiters purpose as a depowering tool. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />


"House prices have risen by nearly 25 percent over the past two years. Although speculative activity has increased in some areas, at a national level these price increases largely reflect strong economic fundamentals." – Ben Bernanke – 2005
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: Buccaneer] #138229
04/02/08 12:03 PM
04/02/08 12:03 PM
Joined: Sep 2007
Posts: 531
Lake Murray SC
FasterDamnit Offline OP
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FasterDamnit  Offline OP
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Lake Murray SC
Pics wold be much appreciated!


Race cheap, race faster, Damnit!

E-Scow
24' ULDB

18HT hulls plus Gcat 5.7 rig = 18GT!
Re: Mast rotation 4 boomless cats necessary 4 raci [Re: FasterDamnit] #138230
04/02/08 06:15 PM
04/02/08 06:15 PM
Joined: Apr 2002
Posts: 195
White Bear Lake, MN
h17racer Offline
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White Bear Lake, MN

Jim, attached pic is how I setup my 5.5 Uni. Front rotator, blocks and front crossbar mounting blocks.

I over-rotate downwind. Only use upwind when I need to induce a rotation angle.

Sail fast, Tom G

Attached Files
140863-UniRotator.jpg (116 downloads)
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