DSII Design Changes

Topics primarily or specifically about the DS2. Many topics are of general interest, so please use forum sections on Rigging, Sails, etc. where appropriate.

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DSII Design Changes

Postby IslandFarmer » Thu Apr 22, 2021 7:37 pm

Hello,

In response to a post I made elsewhere (excerpted below) GreenLake suggested I start a new thread to see if anyone has compiled design changes for DSII as has been done for DSI. My questions stems from the following observation.

The drawing on the cover of Roger Conrad's DSII Manual (as well as drawing 6.4 Rudder Head Assembly) shows a different rudder-tiller configuration than I have on my boat, built March 1983 (HIN: XDY 12250 M83). Based on the descriptions and images at D&R Marine, I'm guessing that mine — with the tiller passing through a black metal rudder head — is a newer version. It looks similar to what D&R Marine is selling for DS II & III (for DSII 1983 and up).
dr132 Rudder & Tiller DS II & III.jpg
dr132 Rudder & Tiller DS II & III.jpg (16.73 KiB) Viewed 668 times

It appears that this change was made towards the end of 1982. This is not one of the differences Roger lists on page 4 of his book.

GL suggests that I first try to establish if what I have is a factory original, so that is my first question.

Beyond that I wonder if there are any other differences between what Roger has documented and what was being turned out in 1983. : )

FYI, D&R sells this for DS I & II (1959 to 1982 - 1/2).
15664 Rudder & Tiller for DS I & II.png
15664 Rudder & Tiller for DS I & II.png (105.57 KiB) Viewed 668 times
1983 DSII 12250
Stonington CT
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Re: DSII Design Changes

Postby GreenLake » Fri Apr 23, 2021 4:40 am

In looking at the picture of your rudder (sorry, I had been focused on rudder head/tiller) it occurs to me that that shape is unlikely to be class legal, therefore making it unlikely for the assembly to be factory original. That bottom rounded shape is required; now, if you have no intention of racing in DS sanctioned event, then you might not care and enjoy what you have. But if you had planned on racing, then you may have to source or build a class legal rudder.

That aside, you DSII owners have had the benefit of Roger's book. (No such thing for the DS1). However, if he doesn't list all the minor model year changes then collecting them here might be of interest. People always want to know whether something is original or an aftermarket upgrade, and once these boats get a bit older, it becomes hard to tell.
~ green ~ lake ~ ~
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Re: DSII Design Changes

Postby IslandFarmer » Fri Apr 23, 2021 8:44 am

Hmmm.... interesting. TY
1983 DSII 12250
Stonington CT
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Re: DSII Design Changes

Postby tomodda » Fri Apr 23, 2021 10:55 am

Yes, I've wondered about that D3/DS2 rudder myself. Here's the story, as far as I can tell - no, that rudder is not class-legal, it's for the DS3. The ENTIRE DS3 design is not class legal for racing because the transom is higher. So the manufacturer (whoever that was in 1987-89) went with a new rudder design. Apparently it fits on the DS2 as well, so Rudy is selling them for either boat. Here's my source, for what it's worth:

https://forums.sailboatowners.com/threads/daysailer-iii-rudder.161219/

The DS3 rudder has an obviously higher ratio. However, that is not necessarily "better." The argument for high-aspect is lower drag (which is debatable), the counter-argument is that a high-aspect rudder tends to stall earlier and suddenly. The original rudder is more "forgiving" and does not have significantly more induced drag. Low-aspect vs High-aspect considerations are more complicated than just the previous two sentences, feel free to google, but that's the basics of it. "The Juice isn't worth the Squeeze," Uffa Fox knew what he was doing.

Now, Foil Shape is a whole other story. The original rudder is pretty much a slab with pointy ends. Dunno about this DS3 rudder. Getting a decent airfoil onto my rudder is one of my "round-to-it" projects. Fortunately for me, I have a spare rudder, so I can afford to experiment, because otherwise I'd be building a new one from wood/glass/epoxy.
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Re: DSII Design Changes

Postby GreenLake » Fri Apr 23, 2021 4:17 pm

Getting a class-legal rudder when you plan on racing would be good. In that case, you'd stay well away from a stock rudder, because of the poor foil shape.

For daysailing, none of that matters. For extended cruising, you may need to watch whether whatever rudder design you have is beefy enough to handle a rough patch.

Other than that, go sailing!
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