Boom vang versus gnav

Expertise and know-how available for all builders from Class Members

Moderators: admin, Kevin

Boom vang versus gnav

Postby monsters inc » Tue Oct 31, 2017 3:43 am

I have been rigging my boom this week. I will be running a rear bridle, and a centre swivel and jammer. Next up the vang. Or gnav. I have vang hardware , but could easily build the track and pole for a gnav. The attraction of the gnav is the extra space under the forward boom. Pitfalls could be mainsail shape on one of the tacks. Vang advantage, simplicity, less pressure on the gooseneck. Disadvantage , less angle to mast base due to the compression post,deck stepped mast. Any comments appreciated.
Does the vang on the current boat fleet handle the loads adequately in a blow, if so, how much advantage are you using?
Finally, how high above the deck have the booms been mounted? Thanks M
monsters inc
 
Posts: 6
Joined: Tue Apr 10, 2012 12:08 am

Re: Boom vang versus gnav

Postby Tim Ford » Mon Nov 13, 2017 5:55 pm

Hi Marko, I do not have any experience with the Gnav on an i550, but before I started building mine I spent time trying to figure out whether or not to buy a Viper 640 or start building. (I started building) The guy I knew with the Viper had an early boat that came w/o a Gnav (had a traditional vang arrangement) and then he retro-fitted a Gnav. He loved it. He said it was by far a better arrangement (even though the Viper really doesn't have much of a "cabin") it freed up the cockpit for tacks and jibes with no discernible loss in performance. I got impatient and just finished my boat with a vang, but if I had more time, I'd definitely go with the Gnav. An additional benefit is you wont need a boomkicker, which is my next upgrade -- unless I say screw it and decide to finally run the Gnav.
Tim Ford
 
Posts: 445
Joined: Sun Mar 27, 2011 1:25 am

Re: Boom vang versus gnav

Postby monsters inc » Thu Nov 30, 2017 4:56 am

Well, I repurposed some old harken track and a car. Used a whisker pole section 4 feet long and a 4 to one vang block. Drilled and tapped for mounting screws . That part was easy. Fitting the bottom of the pole to the car with a pin took some carving of high density plastic. I am thinking that the goose neck for the top of the gnav may have to incorporate a tab to mount some shrouds to, for preventing the mast moving forward. Although my viper mast still has its liner in place so it may be over thinking... If someone could direct some tips on uploading photos I would be glad to share them but most of my picture files are too large to add them here. Cheers , Mike
monsters inc
 
Posts: 6
Joined: Tue Apr 10, 2012 12:08 am

Re: Boom vang versus gnav

Postby admin » Thu Nov 30, 2017 5:55 pm

Mike if you want to send the pix to me at timford AT nbayracing DOT com

I can easily downsize them and post them under your name. (hint: I'd love to see the pix)
admin
Site Admin
 
Posts: 392
Joined: Fri Mar 25, 2011 4:17 pm

Re: Boom vang versus gnav

Postby admin » Thu Dec 07, 2017 11:27 pm

Here are some of the photos from Mike's build (nice job!) I'll put them up and Mike can caption them

1.
Boom.JPG


2.
Gnav.JPG


3.
Starbrd side.JPG


4.
white strabside.JPG
You do not have the required permissions to view the files attached to this post.
admin
Site Admin
 
Posts: 392
Joined: Fri Mar 25, 2011 4:17 pm

Re: Boom vang versus gnav

Postby admin » Thu Dec 07, 2017 11:29 pm

a few more from Mike:

5.
TillerRudder.JPG


6.
Mast step.JPG


7.
OB transom.JPG


8.
keel foil and bulb.JPG
You do not have the required permissions to view the files attached to this post.
admin
Site Admin
 
Posts: 392
Joined: Fri Mar 25, 2011 4:17 pm


Return to Building an i550

Who is online

Users browsing this forum: No registered users and 1 guest

cron