tuning guide for a CD33

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tgilson
Posts: 6
Joined: May 15th, '05, 11:30
Location: Cape Dory 33 #17, Everett, WA

tuning guide for a CD33

Post by tgilson »

I am finally getting ready to step the mast after repainting and re-rigging. Does anyone know of a tuning guide for a CD33? I cannot seem to locate one on the site. Maybe a sailmaker CD owners tend to use?
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tartansailor
Posts: 1525
Joined: Aug 30th, '05, 13:55
Location: CD25, Renaissance, Milton, DE

Tuning Guides Are Nice, But:::

Post by tartansailor »

Andy Denmark just very recently posted what I thought to be a very practical common sense regimen for tuning standing rigging.

Having a need to lower my mast last week, I thought I would give Andy's procedure a try on raising.

Am very happy with the results; all without the use of a Loos gage, except to record the numbers after sailing and securing turnbuckles.

Dick
Viam Inveniam Aut Faciam
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GeorgeV
Posts: 109
Joined: Feb 5th, '05, 22:45
Location: Peace & Quiet, Tayana 37
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Post by GeorgeV »

Here is the guide I use for my boat:

Cape Dory 33

Suggested Shroud Tension Chart (1x19 SS cable)

Backstay* is 9/32" w/breaking strength of 9,900 lbs set at 15% or 1,485lbs
Forestay* is 9/32" w/breaking strength of 9,900 lbs set at 15% or 1,485lbs
Uppers are 9/32" w/breaking strength of 9,900 lbs set at 12% or 1,188lbs.
Lowers are 1/4" w/breaking strength of 8,200 lbs set at 12% or 984lbs

*Backstay tension would, of course, have to be adjusted to maintain a straight mast with the desired forestay tension. Since the forestay makes a smaller angle to the mast, it automatically will be at a slightly greater tension but normally around 15% of breaking strength.

** Roller furling can only be set by backstay tension arounf 15% of breaking strength

Uppers & Lowers are set normally around 12% of breaking strength

Mast should be straight with no bend or rake

Sources:
Loos & Company, Cableware Division
http://www.loosnaples.com/howto/90-91gauges.htm
GeorgeV
s/v: Peace and Quiet
Tayana 37
Essex, CT
http://sailingonisabelle.yolasite.com/
Paul D.
Posts: 1272
Joined: Feb 6th, '05, 20:52
Location: CD 33 Femme du Nord, Lake Superior

Post by Paul D. »

All that sounds good to me. For a big picture I would use this order:

At dock, set cap shrouds so mast is centered using main halyard bringing down to a stantion base, check mast at the deck partners.

Set fore and aft placement by setting forestay (Placement) and then set backstay tension.

Set fore and aft lowers to be about equal tension on both sides.

Under sail: Check mast column and adjust fore and aft lowers on leeward side accordingly for a straight mast.

Clean up and pin and tape turnbuckles, secure mast boot etc.

Best of luck, it is kinda fun if a little tedious with all the adjusting,

Paul
CD 33 Femme Du Nord
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