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Keel Chordlengths

PostPosted: Fri Mar 12, 2010 12:43 pm
by Rolf
Fellow Evelyners:

Since I am building my trailer in the absence of the boat, I need some critical measurements of the keel:

1. Height of the keel
2. Chord length at the bottom
3. Chord length at the top
4. Chord length at 10 and 16 inches from the bottom.

Help from the generous soul who provides these gets a virtual six pack!

Thanks in advance

Re: Keel Chordlengths

PostPosted: Fri Mar 12, 2010 7:55 pm
by darkstar32170
Weather permitting I will go measure "Dark Star" tomorrow afternoon for you. Its only a mile and a half from me.

Re: Keel Chordlengths

PostPosted: Sun Mar 14, 2010 11:33 pm
by Rolf
darkstar32170 wrote:Weather permitting I will go measure "Dark Star" tomorrow afternoon for you. Its only a mile and a half from me.



David . . . thanks so much!

Re: Keel Chordlengths

PostPosted: Sun Mar 14, 2010 11:52 pm
by darkstar32170
Sorry,, haven't been able to get to the boat this weekend. It poured all weekend - lots of severe flooding in the area. Will get there as soon as the weather clears - maybe tomorrow afternoon.

Re: Keel Chordlengths

PostPosted: Tue Mar 16, 2010 7:53 pm
by darkstar32170
The weather finally cleared. I don't know if you saw the national news but over the weekend and into Monday we had over 6 inches of rain. The keel dimensions are as follows: Length across bottom = 28" length at the root (top) = 54" height of keel along trailing edge (vertical) = 60" Additionally from the keel trailing edge to the stern = 14'-4" and from the LWL. At the bow to the leading edge of the keel at the root = 11'-2". If you need anything else let me know.

Re: Keel Chordlengths

PostPosted: Tue Mar 16, 2010 8:51 pm
by admin
SHoot, Russ sent me a whole lot of info, offsets, etc as a pdf and word.doc and I been too busy to post them....see if I can get em on here now.
Thanks Russ!!!

hmmmm...word.doc no go....I can send as an email if you email me at: webwolf@nbayracing.com

Re: Keel Chordlengths

PostPosted: Tue Mar 16, 2010 9:06 pm
by admin
Also from Russ re: the keel offsets:
----------------------------
Also, on the site someone was asking for keel measurements to make a
trailer. Under the General Chatter forum. From the keel diagram they
can determine the other measurements wanted. Any measurements need my
boat is just 5 minutes away and on the trailer. Not sure why they need
this for a trailer unless they will have a guard for the keel. Sounds
more like actual keel offsets they are looking for. I have attached the
offsets I used on my keel. Somewhere there was a page that had the
offsets for the bottom of the keel. I compared those to offsets and
came up with the 65010 NACA section used. I assume it was the same
section all the way up, however, thinner at the top (say 9% camber)
would be better but the Fiberglass sump is very close to the 10% section
and any smaller would have structural challenges. This section was a
perfect match with my keel prior to the operation. With these numbers
anyone can create templates for fairing. I wonder how they compare to
what Pterobyte bought from Computer keels.
-----------------
offsets below as jpg files

Re: Keel Chordlengths

PostPosted: Tue Mar 16, 2010 10:26 pm
by admin
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Re: Keel Chordlengths

PostPosted: Tue Mar 16, 2010 10:29 pm
by admin
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Re: Keel Chordlengths

PostPosted: Wed Mar 17, 2010 10:45 am
by Rolf
All . . this is just awesome!

Thanks for the information, it is ALL useful to me and provides me with the exact info I need to proceed.

I just bought a case of the best virtual green Irish Ale for all who contributed . . enjoy!!

and . . yes . . . I know you East Coast guys got hammered over the last weekend . . . hope there wasn't any damage incurred by anyone. I'm talking about the weather, in case I was being ambiguous :o)

rolf

Re: Keel Chordlengths

PostPosted: Wed Mar 17, 2010 5:29 pm
by musicman
darkstar32170 wrote:The weather finally cleared. I don't know if you saw the national news but over the weekend and into Monday we had over 6 inches of rain. The keel dimensions are as follows: Length across bottom = 28" length at the root (top) = 54" height of keel along trailing edge (vertical) = 60" Additionally from the keel trailing edge to the stern = 14'-4" and from the LWL. At the bow to the leading edge of the keel at the root = 11'-2". If you need anything else let me know.


Very interesting that you have a total fin depth of 60". I have measured a few of these boats but never a Formula built one. The earlier C&C's are around 59" the later ones 57-58". It seems to me that the later C&C boats had issues with the mold bowing out as they are short but fat (thicker than the sump).
My old boat around 58.5"-59, which I was totally attacked over after winning KWRW in 05. People claimed I had added to it..... that wasn't what made Remedy 30+ sec/mile faster than the fleet! It was the sails, tuning & sailors.

It would be worthwhile to try & get all the keel depths possible to address this issue. I would think that the early Formula boats should be treated as the standard as they are closet to the original design & plans Bob had in mind, (as long as they are not over 6' of draft.)

Re: Keel Chordlengths

PostPosted: Thu Mar 25, 2010 9:21 am
by darkstar32170
I went back to check the keel dimensions I posted a couple days ago after seeing the keel offset table and dimensions. My remeasurement shows that my keel depth (measured along the trailing edge of the keel) is 59" and not the 60" in reported earlier. That's still one inch more than that shown in the offset table. I know that there is a significant amount of difference among the various boats. I had the opportunity a couple years ago to compare my rudder to the rudder on "Bloody Hell" and put a taped measure to both of them. Both were similar in profile, width, and thickness but mine was about 2" deeper. I've always felt that the boat could use a little less rudder. It might make things balance a little better and offer fractionally less drag. Certainly we don't lack in the control department as I've never had the rudder overpowered.

Re: Keel Chordlengths

PostPosted: Thu Mar 25, 2010 8:55 pm
by musicman
darkstar32170 wrote:I went back to check the keel dimensions I posted a couple days ago after seeing the keel offset table and dimensions. My remeasurement shows that my keel depth (measured along the trailing edge of the keel) is 59" and not the 60" in reported earlier. That's still one inch more than that shown in the offset table. I know that there is a significant amount of difference among the various boats. I had the opportunity a couple years ago to compare my rudder to the rudder on "Bloody Hell" and put a taped measure to both of them. Both were similar in profile, width, and thickness but mine was about 2" deeper. I've always felt that the boat could use a little less rudder. It might make things balance a little better and offer fractionally less drag. Certainly we don't lack in the control department as I've never had the rudder overpowered.


Cool that makes more sense. 59" seems to be pretty common.
I had the chance to pick up the rudder from Bloody Hell in KW (it was laying in the back of the truck) weighed at least 30 lbs less than mine did.
The 32 rudder is HUGE....!

Re: Keel Chordlengths

PostPosted: Fri May 07, 2010 8:57 am
by musicman
It should be noted that the table above DOES NOT list the correct depth for the keel fin.
The plans for the boat show a 59.5" fin not the 58" listed above.