wharram windvane on a tiki 30 rudder

[Bart]

Is there somebody who managed tot Mount the trimtap on the back of the tiki 30 rudder? I Like the simpel, non electric form of it.
Regards, bart

[Rory McDougall]

Hi Bart

I built one last year. Works great. Made the vane a bit smaller than wharram specs. For trim tabs I used stainless steel universal joints on the rods to allow for the change of angle along the trailing edge. Used it for two seasons now and the universal joints seem to be holding up just fine on the waterline.

Cheers

Rory

[Rory McDougall]

Here are some pics.

[Rory McDougall]

I can email you some videos of Wilson in action (my windvanes name!) if you send me an email address.

[chris.t.schupp]

Hello Rory. I would like to know more about your stainless u joint. I thought about using one but didn’t find any suitable hardware. It would save trimming and fairing. I don’t see and pics. Could you post some please. Thanks

[Rory McDougall]

Pics posted above. I bought 304 stainless universal joints from springfixlinkages.com here in the uk. Not 316s/s but they dont appear to be corroding as yet. I used the 10mm ID for 10mm rods, drilled them on a drill press to be able to bolt with 3mm bolts. Springfix part # R3694.010

Hope that helps

[chris.t.schupp]

Hello Rory Thanks for the info. I found your pic. That looks great. I haven’t decided how I will do it yet but will post pics when I get it done. I always appreciate any Knowledge others share with me. Thanks again

[Ricardo Aráoz]

I don't know if I'll be able to explain myself. I'd go with Rory's idea but wouldn't use a universal joint. Just end the rod shy of the trim tab. Then attach to the rod a U shaped piece of metal, horizontal (parallel to the water line) and with the open part of the U looking backwards. And from the aft part of the trim tab a smaller rod that will go into the U. So when the upper rod rotates it moves the U which transmits the movement to the smaller rod attached to the aft of the trim tab.

Some experimenting needed to make sure the trim tab rod won't go out of the U, that's all. Cheap, easy to fix.

Sorry for my English, don't know if it was clear enough.

[Bart]

Rory, Chris and others, thank you for your input. I had some computer trouble but all i working again..

I am pleased there are solutions to add a trimtab to the tiki rudder and the pics and info certainly help to schose.

With the universal joint i am worried abut the extra friction, but if it has proven itself.... I don't have to reshape the rudder to much, thats a plus.

The way chris started was my first idea, but i was afraid to change to much about the size/shape of the rudder. I asked wharram what to do and some time ago my question is forwarded to Hanneke Boon, 'll post her comments here if thats alright with her.

to be continued, ik a month my boat goes out of the water and 'll start with the trimtabs.

Thank you all.

Regards,
Bart

[chris.t.schupp]

Hello Bart. I know my picture is somewhat confusing. The amount of rudder to trim is not much. Less than 10% of the total rudder area about 40 square inches to align the axis of the trim tab. Will end up looking the same as the Tiki 31 drawing in the Wharram plans drawn by Hanneke. I will post again when I get a chance to work on the boat

[Bart]

Hello Chris,

Your photo is fine, when my boat is dry, i'll probably make the the same mok-upp and see what way to go.

And Rory i have send you a friend request so we can exchange video. Writing mail addresses in public fora can result in a lot of spam.

By the way, thanks for your advice on sailmakers, i have a new main from Rolly Tasker and i am pleased with it.

Thanks,

Bart