Hobie Cat Forums

It is currently Sat Oct 25, 2014 10:16 am

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 13 posts ] 
Author Message
 Post subject: Mast base rotation
PostPosted: Sat Feb 08, 2014 4:04 am 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
I was sailing today on our H14T and I noticed that the mast rotates to approx 90 degrees on either tack, the steps on the mast base and the base on the crossbar don't contact each other to stop this over rotation. If I recall correctly I have something like 54in of mast rake.

Am I loosing speed by having this excess rotation or any thing else?

It looks like if I made the mast a little more vertical they would limit the rotation.

Ideas?

Thanks


Sent from my iPhone using Tapatalk


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Sat Feb 08, 2014 9:01 am 
Offline
Site Rank - Old Salt

Joined: Wed May 05, 2010 8:28 am
Posts: 744
Location: Clinton Lake, KS
Do you happen to have pictures.. Over rotating will slow you down heading upwind for sure..


It will not only change how the air "enters" the sail, but also change how the mast bends, giving a different sail shape.


Top
 Profile  
 
 Post subject: Mast base rotation
PostPosted: Sun Feb 09, 2014 4:40 am 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
ImageImage

G'day, with the side rails level and hanging a spanner from the halyard there's 50inches to the sail cut out on the mast rake. It's close to the back of the tramp. And there's only 1 hobie mast bearing disc in there. You can see on the pictures how the mast rotation is not limited.

If I bring the mast rake back to 40inches the mast base and bottom just start touching each other to limit rotation.

Any advice?

:)


Sent from my iPhone using Tapatalk


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Sun Feb 09, 2014 4:07 pm 
Offline
Site Admin

Joined: Tue May 27, 2003 12:44 pm
Posts: 9136
Location: Oceanside, California
That is a very old version of base and step casting. Previous to 1982. Newest set would be from 2004 and allows max rake. You can rake forward with what you have, but then will be pushing the bows down harder. I'd replace the castings.

_________________
Matt Miller
Director of Parts and Accessory Sales
Hobie Cat USA


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Sun Feb 09, 2014 5:18 pm 
Offline
Site Rank - Old Salt

Joined: Mon May 09, 2005 10:25 am
Posts: 2591
Location: Jersey Shore
Or you could cut the rotation stops off of the mast base all together and install a rotator arm (like on the Hobie 17, 18, 20, etc.). Adding the rotator arm gives you the ability to make adjustments to the mast rotation while sailing and this modification is now class legal under the racing rules. It may also be a less expensive alternative to changing out the mast base and step.

sm


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Sun Feb 09, 2014 6:56 pm 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
mmiller confirmed what I was starting to think. Could I either weld (or tap and bolt) a peice of aluminium on top of the old step at the front to get the base to contact it at my current rake?

Is 50inch of rake a good setting to use and am I losing much speed with the over rotation?

Here's a pic.


Thanks guys. :)Image


Sent from my iPhone using Tapatalk


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Mon Feb 10, 2014 3:49 pm 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
I've had two shops quote $150 to weld a piece of aluminum plate to the top of the step. I think that's excessive. Are the castings very thick? I might try grinding the casting down on the end of the mast and the receptacle in the step but I'll drill a small pilot hole in each to measure their thickness to see if I can remove 3mm off each.


Sent from my iPhone using Tapatalk


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Mon Feb 10, 2014 5:11 pm 
Offline
Site Rank - Old Salt

Joined: Sat Oct 29, 2011 4:27 pm
Posts: 556
Location: Central Oregon
Id just keep an eye on ebay for newer castings. Or just get some new ones.

_________________
1980 H16
1997 Wave


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Mon Feb 10, 2014 8:20 pm 
Offline
Site Rank - Admiral

Joined: Tue Feb 03, 2009 6:53 am
Posts: 238
Location: Storm Lake, IA
ImageI think SRM has your best option with the rotation bar. Inexpensive, easy to install, doesn't involve welding aluminium and best yet You dont' have to mess with the dolphin striker.
http://www.murrays.com/mm5/merchant.mvc?Screen=PROD&Product_Code=25-304&Category_Code=C-MR&Store_Code=MS


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Tue Feb 11, 2014 8:43 am 
Offline
Site Rank - Old Salt

Joined: Thu Jun 05, 2003 9:57 am
Posts: 1604
Location: Clear Lake Iowa
There is a JIB on that boat! Remove it. That'll fix part of the problem. Then put on a rotator like Hobieandy says. That is my sail you can see on Herb's right ear btw.....


Top
 Profile  
 
 Post subject: Mast base rotation
PostPosted: Tue Feb 11, 2014 6:58 pm 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
I'm gunna try removing 3mm off the mast end and 3mm off the mast step to get the 6mm drop. The mast end is 7mm thick and step is 6mm, if it doesn't work out I was up for a step anyhow.

It was easy removing metal from the base with a belt sander, but the step is taking more time with the internal surface.


Sent from my iPhone using Tapatalk


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Thu Jun 19, 2014 4:23 am 
Offline
Site Rank - Captain

Joined: Thu May 23, 2013 12:02 am
Posts: 109
Location: London
How did this turn out in the end?
I have the same issue on my old H14 Turbo.
http://www.hobiecat.com/forums/viewtopic.php?f=17&t=51162

_________________
Hobie 14 Turbo (~1979)
Hobie 16 Carumba (1983)


Top
 Profile  
 
 Post subject: Re: Mast base rotation
PostPosted: Sat Jun 28, 2014 3:22 am 
Offline
Site Rank - Deck Hand

Joined: Thu Feb 06, 2014 3:38 pm
Posts: 16
I haven't had it out since cause of winter, but there's still around 4mm left on each end, bit time consuming grinding it to the correct shape, but all good now.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: Google [Bot] and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group