Profile to F21 lifting rudder

Anything that doesn't fit into the other Physical Systems categories
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newt2u
Posts: 236
Joined: Wed Sep 11, 2019 11:24 am
Location: UK

Re: Profile to F21 lifting rudder

Post by newt2u »

Just a follow up, we took Rockin from Shropshire to Milford Haven last week and launched her. As it was such a nice couple of days we took an afternoon sail up to Dale and back to try out the improvements made over the winter. The rudder behaved really well and even when well powered up had only minimal weather helm and good control. The only issue we had was that as soon as we reached about 5.5 kits the rudder tended to lift a bit. Not really an issue as I just need to add a bit more friction by tightening up the bolt on which it swivels. It was a bit annoying on the day as we topped out at 6.5knts at one point and that was without the spinnaker. I posted a vid on Vimeo of the sail.

https://vimeo.com/539588034
IMG_1344.jpeg
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Rockin - F21 twin drop keels - located Whitehaven, Cumbria, UK

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newt2u
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Joined: Wed Sep 11, 2019 11:24 am
Location: UK

Re: Profile to F21 lifting rudder

Post by newt2u »

Followup to the followup.

Although better with more friction, the rudder is still pushing back a little so I think I am going to have to lock it in place while under sail. I'll drill a hole through all three plates close to the pivot and shove a split pin through there. I guess there more force on it with the profile being thicker. It certainly gives me more lift with less deflection.
Rockin - F21 twin drop keels - located Whitehaven, Cumbria, UK

iansan5653
Posts: 101
Joined: Sun May 09, 2021 4:39 pm

Re: Profile to F21 lifting rudder

Post by iansan5653 »

Sorry to revive an ancient thread, but my F21 rudder is starting to reach the end of its useful life. I'm considering replacing it and was excited to find this post. However, my F21 has a fixed rudder and I haven't seen any info on a lifting rudder for the boat. Was that rudder original, or did you repurpose another boat's blade? It seems like a j/24 rudder might work, though that are also fixed.
Ian Sanders
1983 Freedom 21 - Shoal Draft
St Petersburg (Tampa Bay), FL

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newt2u
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Joined: Wed Sep 11, 2019 11:24 am
Location: UK

Re: Profile to F21 lifting rudder

Post by newt2u »

Hi Ian, just noticed this post.

I think this lifting rudder was standard on the UK twin lifting keel version of the F21. With the keels up it only draws around a foot, so a fixed rudder would not be too useful in that situation. If you are getting a new one having a profile certainly helps in stronger winds. What is wrong with your rudder?
Rockin - F21 twin drop keels - located Whitehaven, Cumbria, UK

iansan5653
Posts: 101
Joined: Sun May 09, 2021 4:39 pm

Re: Profile to F21 lifting rudder

Post by iansan5653 »

Ah I see, that makes sense. The shoal draft draws 2 ft, so I think the rudder is about even with the keel on my boat.

I'm actually not totally sure if my rudder needs replacing. I need to take it off the boat and see if the cracks around the brackets are structural or purely cosmetic. Unfortunately taking it off is easier said than done as the pin is bound to the bracket. If I do replace it I'll definitely be looking at a higher performance profile.
Ian Sanders
1983 Freedom 21 - Shoal Draft
St Petersburg (Tampa Bay), FL

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RadioZephyr
Posts: 259
Joined: Mon Jun 27, 2016 10:04 am
Location: Boston, MA

Re: Profile to F21 lifting rudder

Post by RadioZephyr »

Hey Ian,

I remembered you said you needed a rudder for your F21, and I’m at Paul Dennis’s shop and I noticed that he has one. Let me know if you want a picture of it.
Josh
Sunset Spy
F38, Hull #152
Boston, MA

iansan5653
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Joined: Sun May 09, 2021 4:39 pm

Re: Profile to F21 lifting rudder

Post by iansan5653 »

Hi Josh, I totally missed your post and just started working on this project now. I really hope Paul still has that rudder as mine is completely unsalvageable. I've reached out to him directly. Hopefully I can avoid building one as I don't think it's something I can reasonably do in my apartment :D
Ian Sanders
1983 Freedom 21 - Shoal Draft
St Petersburg (Tampa Bay), FL

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RadioZephyr
Posts: 259
Joined: Mon Jun 27, 2016 10:04 am
Location: Boston, MA

Re: Profile to F21 lifting rudder

Post by RadioZephyr »

Oh yeah, I was wondering that when I saw your posts about it.

Don’t worry, I was down there on Sunday and it’s still there. The hardware isn’t on it, but I think Paul removed it and put it aside when he scrapped the boat.
Josh
Sunset Spy
F38, Hull #152
Boston, MA

iansan5653
Posts: 101
Joined: Sun May 09, 2021 4:39 pm

Re: Profile to F21 lifting rudder

Post by iansan5653 »

Looks like he's got it! Shipping it down here will be pricey but looks like my best option. Hopefully I can get on the water soon.

I'm very jealous that you are close enough to visit - I definitely hope to make it up to Rhode Island and check out Warren River in person eventually.
Ian Sanders
1983 Freedom 21 - Shoal Draft
St Petersburg (Tampa Bay), FL

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