Freehand self steering questions

Hey Guys, My name is Ben, I am from south florida and I sail an allied seawind 30 that has been converted to a cutter, and then further converted in BCC style with a big bowsprit and boomkin. this was all done with the goal of building my own trimtab/backstay air vane steering gear…

the trim tab is built and tested along with the slotted tiller and locking mechanism… I am about to start construction of the air vane and I have few simple questions for someone firmiliar with the gear…

  1. What is the diameter of the line drum on the back stay?

    • I have an Edson 16" dia aluminum drum I am planning on using…
  2. what are the approx. dimensions of the airvane/sail?

    • 4’ x 16" is what im thinking looks right, not trying to copy the freehand exactly just get close…
  3. When setting up the counter weight on the air vane, What kind of balance am i after? (perfectly balanced?, slightly Vane heavy?, or slightly counterweight heavy?

Thanks guys
Ben
Crackertail - 1963 Allied Seawind 30 hull #25

Hi Ben,
I have the Freehand system. I also built one myself for my previous boat, a falmouth 22 before there was the freehand.

There is a book out there on the design of self steering systems, but I can’t remember the name. I will be returning to my boat this evening and will get you dimensions then.

You need to have the sail perfectly balanced. It also helps a great deal to build as light as possible. One of these days i hope to replace my system with one made out of carbon fiber. From my studies and experience this will greatly enhance the performance of the system. Once you add a counterbalance the system can get heavy. This has a lot of inertia and cuts down on the responsiveness.

Unless someone else chimes in I will give you measurements later today or tomorrow.

Wheel is 16.5 inches diameter
Sail is 16"x5’

Thank you so much Gary!

I got very lucky with the drum diameter and being aluminum I bet its a good bit lighter than the bronze… I love some bronze but think I will use aluminum everywhere on the air vane…

I am building a quick simple frame from 1"x1.5" mahogany and 3/16" plywood, with delrin bushings top and bottom. I will laminate and nice spruce frame at some point…

2 more questions.

has anyone ever provisioned a lock for the sail on the centerline so I can double as a riding sail at anchor?

and your thoughts on giving the vane its own piece of wire with a toggle between the vane and the backstay, or just sliding it up the back stay…

Hi Ben,
just a note about posting. Once you click on “post” it takes a bit of time for it to complete. A new window will pop up once it does.

I don’t know of anyone that has tried using the vane as a riding sail. I believe the sail area would be too small. Also believe it would fairly rapidly wear out any kind of mechanism. You could run a line from your center spoke to each side of your lifelines/boom gallows, or other such area to anchor the system from side to side.

Keep it simple. slide it up the backstay. Unless you were going to install a SSB radio, then you may need to do the toggle. there are other members here that have more info on the radio side of things.

Hello Ben,

Gary mentioned a SSB radio and here is a photo of how to route the GTO cable. Basically, it’s just a hole drilled through the hub of the Freehand wheel.

John Purins
Adventure
2003 Bristol Channel Cutter
Hull number 122