Electric Mainsheet Tender

[BOAT]

As you all know I NEVER am a “post Starter” (although I have ended a few heh, heh heh ), anyways I am starting this “post” to see if there is any interest in this. If enough think it’s a good idea I figure between us all we can make a simple device.

I was thinking of creating an electric main-sheet tender out of an old 12 volt variable speed drill motor that would work in conjunction with the heel angle of 'boat'.

The idea is that the drill motor would let out main-sheet or pull in main sheet automatically based on the heel angle of the boat. My first idea was to just put a winch on the side of the pedestal right here where my sheet cleats off in this picture and put the drill motor in the pedestal:



Please comment with better locations?

What kind of electronics would make the motor run forward and backwards based on the heel angle? I can think of some really crazy relay logic stuff that would work on weights but I assume you guys are way ahead of that and might know of any plug in stuff with the right angle or accelerometer already on the circuit board that might do the job? It would be best if the output is programmable so you could adjust how aggressive you want the sheet tender to react to the angles.

Is this a good idea?

[Y.B.Normal]

Why overcomplicate things? With the camcleat you now have, all you have to do is uncleat the mainsheet.
No chance of electric/electronics failure.

I DO HAVE an "automatic over-heal indicator"...the Admiral screams at me when we get over 20 degrees.

[Russ]

I was thinking of creating an electric main-sheet tender out of an old 12 volt variable speed drill motor that would work in conjunction with the heel angle of 'boat'.

The idea is that the drill motor would let out main-sheet or pull in main sheet automatically based on the heel angle of the boat. My first idea was to just put a winch on the side of the pedestal right here where my sheet cleats off in this picture and put the drill motor in the pedestal:

There was a time in my life when I would have bitten on this idea. I used to love to geek my life up. I still do, but not so much with mechanical stuff.
For now, I'll simply enjoy the pleasure of un-jamming the main sheet or simply turning up into the wind.

I DO HAVE an "automatic over-heal indicator"...the Admiral screams at me when we get over 20 degrees.

I have the same one.

[Catigale]

The same one ? I'm impressed you guys make those WI MT logistics work...

[Lee Ward]

A simple gyro, like those in model aircraft, wired to the drill. The drill would need a signal, power and ground wire like a servo. Possibly the servo board itself could be made to work. The gyro is initialized at zero heel angle. Some gearing or the pulley size would have to be figured out to allow for proper length of travel of the sheet.

[RGF]

And for only $600 right, Boat!? Sign me up!!!



What? Too soon?

[innervations]

It might because I am an electronics and computer hacker but I think the hardest part would be the mechanicals of actually handling the mainsheet. It is relatively easy to build and program a computer controlled http://www.arduino.cc/en/Main/ArduinoBoardUno servo motor (or canabalised drill motor) and switch it forward and reverse based on tile sensing from a gyroscope and accelerometer http://www.youtube.com/watch?v=T0SFAdPUUYs

I am just not sure how to keep the sheet (rope) from getting tangled or caught up. Self tailing winch maybe?

[innervations]

That would be "tilt" sensing. I am not sure of the applications for a tile sensor

[BOAT]

Why why, yes this may be a waste of time. That's why I am consulting you intelligent people before I even consider such a gadget.

The “why” is so I can be free to roam around the boat for a few hours.

As for the 600 bucks that RGF mentions, I do not want this to be a product for sale. I was thinking more of a ‘kit’ that any of us can build, modify, and improve on. I thought any of us that may have use for it might want to build our own and share parts sources and so forth.

I guess I would probably be unable to do this by myself, (I do not have the electronics knowledge), so that’s why I am bringing it up here. If not enough of you guys think it’s worth messing with I will just drop the idea.

Another way to do it is to have the line RELEASE automatically at a certain angle by means of a weighted pendulum release mechanism, (no electricity), and it pays out only a pre-determined amount of line. Then when the boat recovers the spring will slowly wind the line back in to where it was before it released. A mechanical device like that is all I can even consider without electronics help.

You know, the answer to this might very well be a large rubber band! Do any of you have any problems at all leaving the helm for an hour or two under sail with the AP? Is this a non-issue?

You think maybe I should just ignor the occasional gusts of wind and just slet the boat heel over and forget about it? (It's gonna return back sooner or later anyways). So why do we run to the mainsheet and uncleat all the time??

[Lee Ward]

I've gotten my Ms helm and sheets balanced to where I could leave the cockpit for minutes at a time, but not much longer. Admittedly not in high or gusting wind though.

[walt]

A little different angle..

I often sail by setting the main, then maintain some fairly constant heel by adjusting the rudder. You somewhat follow the wind speed and direction.. but its generally a fast way to sail. If the sail is sheeted in more and you sail with the rudder, you generally go up wind more. This type of sailing has a name but I cant remember what its called.

So.. (since Boat has us thinking crazy things..), what if you took an autopilot that controlled the rudder and instead of the input being a direction setting (i.e., the rudder is controlled so that the boat direction matches an electronic compass output), the input to the rudder auto pilot was heel angle. Say you set the desired angle at 15 degrees. The autopilot would adjust the rudder to try and maintain 15 degrees which is very similar to the way I do sail sometimes. You are following the wind rather than a direction but it’s always been relatively fast, especially upwind.

[budgates]

My first thought was, as stated earlier, to use gyros like those made for model helicopters. The mechanical part of it wouldn't be all that difficult to accomplish. No need for a self tailing boat winch. A simple electric winch similar to those used on 4X4 vehicles only smaller would work fine. Rather than having it control the mainsheet directly it could be attached to the base of the mainsheet letting the lower block and everything in and out. This would require a lot less line.

Of course being a mechanical person rather than electrical I'd be inclined to use the basic sheet-to-tiller steering.

[Russ]

The “why” is so I can be free to roam around the boat for a few hours.

I didn't think you guys in California had gusts of wind.

We inland boaters have nothing but gusts of wind. However, when I sailed offshore (Atlantic) I could trim the sails to sail herself for hours.

Honestly, a boat as light as the Mac, I wouldn't trust totally under automatic control like you are proposing. At least with an AP fighting nature.

[BOAT]

I think walt might be uncovering the real answer here. Perhaps the Auto Pilot connected to a wind indicator MIGHT preclude the need to mess with the mainsheet?
I would need to propose such a question to anyone who has an AP that is also connected to a wind sensor.

The only person I know that has an AP connected to a wind sensor is MASTREB.

If MASTREB sees this post maybe he will tell us if having a wind function on our AP will negate the need to tend the mainsheet every time the wind picks up.

Perhaps I need to go back to the old fashioned way to trim sails like they do on old keel boats: (set it and forget it)?
I see by the comments of the engineers here like Lee and innervations and budgates that a device is possible, but apparently there is also evidence the device might not be practical.

Maybe mastreb will tell us about his wind AP and how it works.

[walt]

Controlling the rudder is known power wise (i.e., how much electrical power do you use for an autopilot) but controlling the main sheet is not and simply based on the amount of work it takes to run a tiller vs the main sheet, I would think an automated main sheet would require a lot of power.

Also, for something like the main sheet, the controller would also have to figure out "when in doubt, let it out". You don’t always sheet in to get more power from the sail (and more heeling). Sometimes the sail is stalled and you get more power by letting the sail out. You would almost need more of an algorithm similar to maximum power point tracking in the solar controllers.

Having an autopilot control the rudder based on heel angle - or based on a wind direction meter is also a complicated control job. But.. you have a guy here (Victor with the $600 autopilot) that knows all this stuff very well. I was thinking along the lines of just an option to an autopilot. Normally you would use it in a conventional manner - set a desired direction and the autopilot takes you there. But, it would be just an incremental design to have an option to use pretty much the same hardware but instead of the algorithm trying to cause an electric compass to match a desired heading, a mode might now have (for example) an algorithm trying to cause an electronic heel meter output to match a desired heel angle.

I am not likely to buy this myself – just conversation only.. but I can imagine getting the boat up to some heel angle (with the main and jib set well), push a button and the auto pilot tries to maintain that heel angle. I’m fairly sure the control for this would also get complicated as it’s not exactly a standard linear control problem...