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I'm still mentally designing a kick up rudder for my dory (for beach launchings) and it seems that the rudder cheeks on most designs hang down even with the bottom of the skeg, offering only partial ability to get the rudder up out of the sand and gravel. So, in looking at rudders this weekend at the Port Townsend Wooden Boat Festival, I see many where the cheeks are attached to the rudder blade, not the main rudder providing more "ground clearance" than having the rudder blade swing between cheeks that are part of the main rudder.
Here's an example....why would this principle not work just fine on a dory?
Curt
11 replies:
RE: Rudder cheeks on rudder blade
Laszlo,
Thanks much for the idea...I agree that would work. A couple questions...because as much as I tried, I cant seem to get my screen to fly around the boat to see things like a drone. Is this your boat?
--It appears the top part of the rudder and the rudder blade were cut from one piece of plywood?
--Looks like the cheeks are about the same thickness as the rudder? Are all the pieces about 1/2"?
Thanks!
Curt
RE: Rudder cheeks on rudder blade
Curt,
Yes it is my boat. The rudder was originally a non-kickup rudder - a simple blade carved from 3/4" okuome. Eventually I got tired of the hassles when launching or landing on a beach, or when gunkholing in very skinny water. So I cut the swinging piece, added the cheeks (also 3/4" okoume) and added a 1/2" bolt for a pivot. I secured it with 3 washers, a lock washer and a wing nut. That lets me adjust the friction that holds the blade in place.
I also put a brass clip on top to keep the rudder from floating out of the gudgeons. Normally the weight of the cheeks is enough for that, but I got pooped by a sociopathic power boater's wake and the the transom was immersed to the point that the top pintle popped out as the rudder floated in the wave.
Strictly speaking, the cheeks are probably way overkill in thickness. I could probably have gone done as low as 3/8" with just wood or 1/4" with uniaxial carbon fiber and biaxial glass, but 3/4" is what I had and the extra weight is not an issue, what with the anchor and ice chest up front.
The one thing I'd do differently if I was doing it again would be to use a rounded cut instead of that right angle. But that's just cosmetic so I'll live with it.
Have fun,
Laszlo
RE: Rudder cheeks on rudder blade
Hi Curt,
I bought the CLC kick up rudder option for my dory and am about to finish it and try it out.
i imagine you know they offer this option . Does it also drag at the same level as the skeg as you described in your post ? I beach launch and am hopeful your observation does not include the CLC kick up rudder . I am getting tired of attaching and detaching the standard rudder while rocking in the waves .
thanks
Dermot
RE: Rudder cheeks on rudder blade
Hi Dermot.... I ordered my dory kit with the standard rudder, before they offered the kick up model for the dory. I used the boat one summer with the fixed rudder and didnt like how the fixed rudder dug into the sand on beach launches so I bought the kick up rudder kit. Then on a flat surface I mocked up the kick up rudder pieces would be as laid on top of the original fixed rudder and come to find out the bottom plane of the cheeks of te kick up rudder kit are inline with the bottom of the skeg, see picture below. The white space between the two pieces of blue tape below is the line of the bottom of the skeg. Not what I I was hoping for. SOOO...thus my work to try to either make a swing rudder out of my original fixed rudder, or come up with a totally new design, perhaps using the rudder blade out of the kick up kit, but it likely isnt tall enough to make a rudder where the cheeks are attached to the rudder blade because the bolt that the rudder blade would swing from would have to be a lot higher. We are on the road for the next 6 weeks but if you like I could get the pieces of both rudders out and take more pictures. When we get home I intend to get serious about designing a new kick up rudder from scratch that starts off at leat 4" above the skeg line in the front and curves up to at least double that on the trailing edge..Oh, and it also will have a removable tiller like my original one did.
Did you notice that the kick up rudder blade on the kick up kit is the same thickness as the spacer? How do you handle that?
MMore pictures:
https://picasaweb.google.com/lh/photo/AEVam2hUFpR6JV22iTkwZzFolq1y-t7pqfyiNmzJPv8?feat=directlink
Curt
RE: Rudder cheeks on rudder blade
>>Did you notice that the kick up rudder blade on the kick up kit is the same thickness as the spacer? How do you handle that?
Mr. Beltsander handled it on my rudder.
Just remember to sand the blade, not the spacer :-)
Laszlo
RE: Rudder cheeks on rudder blade
i I Curt ,
Yes. I ultimately did notice the identical part thickness and sand away because I think The rudder can be made to look good and be functional .
I may have a misplaced concern that using the standard dory rudder when beach launching , might cause a stress on the stern sufficient enough to crack the ply so I always rowed out a ways and the crawled over the stern and made the connection.
For example , if a wave lifted the stern and dropped it on the beach or just the idea of dragging it fixed through the sand , even just a few feet, seemed like a risk.
I have stainless over the skeg and everything is holding up well with heavy use.
No need to interrupt your travels to post more images on my account .
I think I have a plan .if you want to update when you return or have extra time that's great and appreciated.
Dermot
RE: Rudder cheeks on rudder blade
Update: Just spent two days at my favorite lake at my favorite camp site where the grass goes right down into the sandy lake bottom and I know for SURE that whatever rudder I end up with has to allow me to pick up the bow by the breasthook to slide the boat backwards into the water and not have the rudder touch at all. I also want to be able to put the boat aft end in toward shore and have only the skeg touch, not the rudder. This will require a rounded rudder shape that starts inline with the bottom of the boat (not the bottom of the skeg) and curves up from there as you go aft...similar to the black rudder in my original picture....Laszlo's approach would also work because the point is that the aft end of the skeg is the "rocker" point. Here is a picture of the "stock" rudder in the water today digging heavily into the sand.
The horizontal blue tape is inline with the bottom of the skeg so you can tell the back of the boat is being held up by the rudder blade in the sand. The rudder needs to be above that line or else picking up the bow would dig the rudder into the sand. Compare that to my mock up higher in this thread where blue tape is inline with the bottom of the skeg on the CLC kit pieces for kick up rudder and you can see that the CLC kick up rudder kit pieces too would dig into the sand so for me, it's confirmed that the CLC kick up rudder will dig into the sand, not what I want it to.
Has anyone built the CLC optional kick up rudder and can share your experience with it clearing the lake bottom when beaching the NE Dory?
Thanks!
Curt
RE: Rudder cheeks on rudder blade
I have just finished building and using the CLC kickup rudder with great satisfaction! I found it works great in either the up or down position which is nice for skimming along in shallow 8" water. No problems beaching.
During the build i took some extra wood off the the part of the rudder inside the checks to reduce some of the binding 3 layers of epoxy produced. a few swipes with the almighty power plane. I would perhaps add some glass to thicken up the gap before gluing up the checks if i did it again
RE: Rudder cheeks on rudder blade
���Buzzard.... Are you able to pull the boat up on shore without the rudder fixed part hitting bottom? Said another way are you able to push the boat backwards (beach launch) without the rudder touching bottom?
RE: Rudder cheeks on rudder blade
It depends a bit on the angles. I'd say the skeg took the load. The rudder checks will touch some but not enough to worry about. I really liked how it performed in shallow water..
RE: Rudder cheeks on rudder blade
» Submitted by Laszlo - Tue, 9/15/15 » 6:07 PM
Or you could just not have your cheeks hang so low. (There's a bad joke in there somewhere, but I'm going to walk away on the higher ground. This is me walking away...)
On the boat below the cheeks stop well above the waterline so when the rudder is completely kicked up the skeg takes the beating and the rudder is out of the sand. In fact, it's mostly out of the water.
Either way should work fine for the dory.
Have fun,
Laszlo