Capri22.net

Posted: Fri Feb 26, 2010 3:14 pm Post subject: Shroud tensions

Steve, I have a question about the Ullman Sail Trim Guide that is downloadable from your website. Definitely a good tool to have aboard for quick reference.

http://www.ullmansails.com/upload/Capri%2022%20Sail%20Trim%20Chart.pdf

Looking at the shroud tensions, the numbers are a bit confusing as the tension is listed in full turns. This is a bit confusing as the numbers shown in the chart look like they should be Loos guage readings. I've been spending a lot of time racing U20s and Vipers the past year and noticed that they had similar confusion in the published tuning guides.

Can you tell us if these tension numbers are for the Loos Model A or PT-1?

Thanks.

tom

Mast prebend as well. IIRC, the standard rig calls for 2" w/ a loose backstay Confused

Posted: Mon Mar 22, 2010 9:41 am Post subject: A Little Help Please . . .

Just bumping this one up. I have my Tall Rig / Fin in the water and I know the tensions are not right. Also, what prebend should be set on the mast and what should the rake be? Could we possibly get the Loos numbers translated to pounds tension? I have a PT-1 as well. (I guess I could contact Loos huh?)

Posted: Mon Mar 22, 2010 9:08 pm Post subject: Tuning Guide

The Ullman Tuning Guide was written using a Loos PT-1. The old syle tension gauge change with age giving you higher numbers as it ages.

and bend for a tall rig? Does max rake on forestay turnbuckle and 2" prebend make sense with a CDI furler?

Posted: Tue Mar 23, 2010 9:56 am Post subject:

Thanks for the confirmation that the numbers listed are PT-1 readings Steve.

I have never been real happy with the way I've had the rig tuned on my boat for the first 3 years I sailed it (SRWK). At the end of last season, I borrowed a PT-1 and checked the tension in my shrouds; using my Loos Model A, I measured around 400 lbs. To my surprise, the PT-1 showed that I was only running with about 250 lbs of tension. This does help to explain why I couldn't get enough prebend unless I used quite a bit of backstay and my main always looked too full. Upwind sailing required too much backstay to get the main to look reasonable and that much backstay made the entry to the jib way too flat.

Posted: Wed Mar 24, 2010 1:58 am Post subject: Hey Auburn . . . .

I have a FKTR and Loos PT-1 too. Boat's not in the water yet, but IIRC I had the uppers at 30 or 31 and the lowers at about 25. Any more than 31 on the uppers put too much tension and the mast starts looking like an S. The part I've always had trouble with is getting the rake/prebend right.

My Loos PT-1 has the Pounds tension in black letters and % break strength in red to the right of the Scale #'s. If yours doesn't have it let me know and I'll post the #'s to match the scale for the various cable widths.

Chris

So, the upper shroud tension numbers listed on the guide are tension measured with a PT-1. Makes sense, and agrees with other numbers on this board indicating around 30 with winds 11-15 knots.

However, I must be missing something because I'm still confused on the right setting for the lowers. The lowers are listed with numbers like 3, 5, 8. This can't be a direct PT-1 measurement because it would be too low based on other reports on this board.

Does it mean subtract this number from the upper? So, at 12 knots you'd have 30 on the uppers and 22 on the lowers?

Any guidance appreciated.

Thanks,
Brett

Posted: Tue Jun 29, 2010 10:19 am Post subject: Lowers

I have my Lower Shrouds set at 12-15 on the PT-1 guage. In light air I will back them of from 15 to allow the rig to sag to leeward in light air.

Posted: Tue Jun 29, 2010 2:03 pm Post subject: re shroud tension

Posted: Tue Jun 29, 2010 3:49 pm Post subject: Re: re shroud tension

Posted: Wed Jun 30, 2010 9:13 am Post subject: Cotter Pins

Instead of Cotter Pins, you can use "Wrap-Pins" which are a cotter pin attached to Velcro. What I do on my boat is use a small peice of Spectra line, and tying the 2 turnbuckles together which prevents them from turning.