Alternative Motorsailer Rig

Good research-- My desired install would be a three blade feathering prop but these things are insainley priced out of my market. In the $5000 range they cost half the price of my new Yanmar 3 cyl. diesel. I have two possible choices a new 2 blade 19in. which i will have to cut the dia. and maybe reset the pitch and a three blade 16x14 which is right on specs for my hull to engine combo. I hate the drag factor of the three blade but just might have to live with it. My present shaft tube is large enough to handle the ultimate system, a variable pitch tube/shafting arrangement but i'd have to sell the house to afford that set up .
Finally got the boat shed/carport closed in for the winter and have two more days of unrelated boat work but then finally I get at the keel. It has been a good delay as in walking past the hull and visualizing the keel work process I have come up with another possibility of the full keel/foil keel/foil skeg mating arrangement to investigate further. The other challenging design feature I have to face next year is raising the deck edge/hull sides before I install the deck beams to allow full headroom. It's good that the present hull has alot of sheer as it allows a tapered rise from 0 at the bow to 10 in approx mid wheel house location running aft. This still allows some sheer curvature which is important in maintaining that old style look. I have to get my part time/as is needed designer and his magical computer program re calculate her stability /righting stats. on this before ballast install. It might mean more wetted surface but speed is not a big concern afterall she is a motorsailer.

 

There are only 3 options I can see to eliminate propeller drag.
1. Controlable pitch prop
2. Folding prop
3. powered prop

I chose the last. The prop wants to windmill when the boat is sailing but thats drag. So applying a small amount of energy is all thats needed to spin the prop at the sail driven speed and a bit more, so there is no drag, and actually positive thrust increasing speed. For me , motor sailing is the ticket to efficiency.

 

Well King Neptune might have blessed me. I put an advertisement on KIJIJI not expecting much in the way of a reply but lo and behold a guy came back to me within three hours --a Vetus set up his dad purchased some time ago for $2000, $4000 to $5000 in todays money and his asking price is the price of a three blade prop. So we will see what it turns out to be--

 

I discovered watching amps and GPS speed allows finding the "sweet spot" as to power. These two 11 inch props of mine, slow me down about one and a half knots under sail alone. Eliminating the drag by force spinning the props gives me back 1 1/2 knots. A bit more juice for positive thrust, so my motors increase my sailing speed by two knots (most of gain is elimination of drag). To do this only costs me about 12 amps at 24 volts. 288 watts. If 750 watts = 1 hp, then I'm applying little over 1/3 horsepower energy. Cheap efficiency. The riptide trolling motors can accept up to 116 amps @ 24 volts. 2784 watts. About 3.8 horsepower between the two motors. Electrical hp has better low end torque, where I'm using it. Ok, nuff said

 

Why nuff said--were you called to chow up . Question : say you're sailing hull speed with a good beam wind on a long tack . If you allowed your props to freewheel do you have a setup to make use of them as generators. ? I ask this because i'v ran beam wind tacks of 2 to 3 hundred miles one leg and often threatened to allow the prop to spin and couple the shaft to a 12 volt alternator.

 

Very interesting question!
One of the many reasons I chose to go with Minn Kota Riptides, is because the motor controller is included, and a very efficient one at that.
Also, they sell an accessory cordless, infinitely adjustable, remote speed control. In my helm drawing, I show it tossed in the glovebox. Actually, maybe I'll wear it around my neck on a lanyard.
Anyway,I can't detect any amps flowing from motors back to speed control box when shut off, with a clamp on ampmeter. Probably controller prevents it or open circuit. I would like to try a switch in the circuit that disconects the control box and connects to a load, maybe some lightbulbs. I'm curious if these motors can double as generators. Drop anchor in a river or where there's a current, "Fill her up, Please. Hi-test."

 

I think your boat if used as a motor sailer would benifit by a low tech gaff rig main and small working jib. the reason is that the center of force is low with this rig and it in a small package is very easy to handle. I owned a 20 ft sloop riged cat boat with such a rig for many years. Easy to set and drop sail on almost any point of sail in less than 15K. Good down wind. Low tech sails easy to make and repair. Did I mention looks really cool esp. if tanbark.

 

Which is more out-dated? Hi-test gas? Or an attendant to pump it for you? In Mexico there is a crew of attendants to pump yours and half dozen more cars simultaneously. I like it. They'll check your oil too, If you ask.

 

Interesting--They should act as generators-but it is possible the controllers disconnect the feed to the field electromagnets if they have such. If they make use of permanent magnets in the fields it would be a simplier circuit. It might mean modification of the controllers and this might be an easy fix. Is there someone in the Minn Kota teck. department you can talk to presenting this question. Some whiz kid ther might jump at the challenge. A big plus if it can be made to do so.---Geo.

 

welcome to the thread eyschulman.
Gaff rig would be interesting, BUT, if you look at the photos a few posts back, you'll see my spars on top the Albin, and next to the bow of the Oday, laying alongside the Albin, is Albins mainsail in a sailbag. A nice sail too! In addittion, I moved the mast as far aft as I could without the boom hitting backstay. Gaff rigs usually use running backstays. I had running backstays on a 27 ft E-scow. Pain in the rear. I need to single hand this boat, with my wife helping some. I'm planning a dressing table in the accomodations, so she can sit in front of a mirror and paint her face several hours each day. Early in our relationship I accused her of being vain. She replied "I'm a woman."

 

Pump gas I owned( not rented)owned a Gulf Oil service for 3 years and I pumped gas, worst buisness I ever owned, worked 7 days a week- 12 to 14 hr. days --worked my *** off -after 3 yrs. upon selling It, broke even-- makes me gag just to recall--what a waste of 3 valuable years.

 

I haven't inquired of Minn Kota, but will some day. I don't think the motors are permanent magnet or they'd advertize as PM motors, an advertizing "BUZZ" word these days. Maybe are pm's and they're keeping it secret. But a competitor could/would disassemble one and find out "secret". They do claim they get 2 or 3 times the service from a battery as competitors trolling motors. Maybe?

 

Viking, In my helm station re-paint, you may notice 3 Perko battery disconnects. I don't want to run heavy wire from battery banks to helm and thence to motor control box. Nor do I want to use solenoids, both types, normally open, normally closed, have drawbacks.
Does anybody make a solenoid operated switch? Momentarily on to close switch, momentarily on to open switch, or...I'm open to suggestions

 

As to your plan to increase topside height, does the hull currently have a harpin? Harpin (hairpin) is a horizontal rib, a structure running inside gunwale like a narrow side deck, following sheer from stem to stern. If so, easy enough to attach verticle ribs on top harpin and run a fiberglass plank outside to enclose. A second harpin on top ribs at new sheer would make entire addition a box girder, very strong.

 

power centers

What is the opinions on mixing old and new batteries in a bank?
I'm considering keeping the multi-racial asst of old lead acid batteries I currently have, and replace them a few at a time as needed.
I looked at power center boxes(3rd photo), for neatness and safety. It's hard to justify their expense of $50 to $70 each, depending on brand and store. Power center includes a plastic box with external battery posts and tie downs, a circuit breaker, a led push to test charge condition indicator, and a couple of 12 volt automobile style plug in sockets for accessories, (I guess you might want to use radar detector on your trolling motor powered fishin boat, to avoid speed traps )

I'm showing here a NOCO plastic battery box for $6.

Perko 9703DP Heavy Duty Battery Disconnect Switch
$7 online

Minn Kota® digital battery meter Price: $16.99
Monitor the level and charge of any 12-volt battery LED display

Add an inline fuse, box and box mounted disconnect less than $15.

The battery tester, only need one. It's portable and could use to test all batteries. Actually I prefer multi-meter, but just for price comparison, I wanted to duplicate the idiot lights available on power centers.

Accessorie sockets? Nah. I'll leave my CB and radar detctor at home.