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…
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…
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…
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?
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.
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.
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
