I am back at work on my footy, and, never having seen one or even examined an RC boat closely I am finding myself uncertain about some parts of the setup. I had no trouble with the hull itself, knowing what I wanted and how to get it, but the details of how things are put together are unknown to me.
My tiller works, but provides less than 45 degrees each side of center. That’s okay with me for now. Changing it will not be easy so I am leaving it. After all this is my first experimental boat. What bothers me now is the length of the sail control arm.
Measuring from the servo pivot to the attachment point of the main (and only) sheet, what is a good length? What I have room for looks short, but will probably work. I’d like a longer arm, but it looks like it would be difficult to fit. The current arm is only about two and three eights inches
I am also struggling with the fairleads for the sheet but that can be modified until I am satisfied.
My servo (Hitec 85) has 90 degrees of throw. Is it possible and worth the effort to try for 180 by adding resistors on both sides of the pot?
Funny, I built the hull in a day or two with no plans outside of a solid idea of what I wanted, but the details of fitting the boat out for RC is what is driving me nuts. I’ve been flying RC for over 40 years, but this is my first boat.
I don’t know the details of how to make a sail either, but at least I know what I want and roughly how to get it.
If this were a full sized boat I would have a lot less trouble!
Pete (still full of crazy ideas, but the sane ones elude me)
Your present servo arm will work fine. But you need to keep the sheet attachment point about that same distance (2+ inches) behind the mast (or less), with the turning block directly under it. This will give you about 90 degrees of control on the boom, which will take you from close-hauled to a dead run. Moving the sheeting point a little further forward will allow the boom to go further forward, which can be helpful in heeling the boat to windward, to balance the sails on a run.
Thanks Walt, I understand the range of motion issues, I was mostly concerned with how short the arm looked in place. I was unsure if I might not be better off moving the servo to allow a longer arm. (or maybe cutting a hole in the side of the boat:rolleyes:)
I’m really looking forward to designing the sail plan and making my first sail.
Sorry, I didn’t completely understand your question. My servo arm is about 2.25". It works very well.
Your first sentence was enough to ease my fears.
I’m a pretty good mechanic, just the idea of controlling so much sail area with so little arm motion worried me a bit. A longer arm attached further back on the boom still puts the same load on the servo so if an arm slightly over two inches works I am home free.
Thanks again Walt.
Use a double purchase arrangement.ie run the sheet from a fixed point in the hull, through a hole or pulley on your servo arm then back to where ever your sheet exits.
you get double the sheet travel with a smaller arm.
I think I am okay since the tip of the arm comes out in a very good position.
I was also thinking of the arrangement with two blocks on either end of the arm with one end of the sheet fixed to the hull, but for now simple is best and the position of the arm is very good considering where the sheet will have to exit.
I can think of better ways of doing it but now that I know a two inch or so arm will work I am going to stop worrying.
All the details of finishing the boat are driving me nuts. Everything needs about five more steps than my initial though. I really look forward to the second boat when I will be better organized.
I look forward to seeing your second Bobabout. My friend Bob is a full scale sailor and has a pond on his property. Maybe I’ll make one for him. He is getting close to eighty and still very active, so maybe it will slow him down a bit!
Stop worrying, Pete…Footys are supposed to be fun!
Your arm length is fine. 90 degrees is fine, too. Footy rigs don’t need much to get full motion, unlike some bigger boats.