Electric motor

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Electric motor

Postby DanaDCole on Thu May 21, 2015 1:53 pm

Someone please explain to me why I should buy a Torqeedo Travel 1003 for $1,999 (68 lb thrust, 28" shaft, replacement battery - $600) when I can buy a Minn Kota Endura Max 55 for $280 (55 lb thrust, 36" shaft).

You really only need about 40 - 45 lb thrust for this boat anyway, and a good 100+ amp-hour battery only costs about $110. The trolling motor will run off the boat's battery just fine with 6 AWG cables from the front compartment to the transom.

If there is a good reason I should buy the Torqeedo instead of a regular trolling motor, please let me know before I spend any money.
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Re: Electric motor

Postby Shudoman on Thu May 21, 2015 2:13 pm

No reason at all. I have a Torqueedo and I'm rethinking that strategy.
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Re: Electric motor

Postby craig on Thu May 21, 2015 2:51 pm

I'm very ignorant about outboard/electric motors. How fast would the boat go in calm water under that much thrust, and how long would a 100 amp hour battery last? I'm trying to decide between an electric or gas outboard. For gas, I like the suzuki 2.5HP, which is $780.
Titania, launched January 2015
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Re: Electric motor

Postby DanaDCole on Thu May 21, 2015 9:02 pm

Crag,

My understanding is that, since this is a keel boat, it cannot go faster than the hull speed which is a little over 5 knots (except in the case of the rare "surfing" event). That rule holds no matter how large a motor you put on the boat, so there is no point in any more than 2 or 2.5 HP, which will easily take it up to hull speed. It's like comparing apples and oranges, but I believe a 50 lb thrust motor generates the equivalent of about 2 to 2.5 hp.

I took a ride in Charles Huie's PocketShip with a 2 HP Lehr (running on propane). It had us clipping along nicely against a pretty strong headwind, mast up. If you don't go electric, I suggest you take a good look at the Lehr ($1,000). More expensive than the Suzuki, but well worth it. No pollution and no annoying fumes.

As to range, there are lots of variables, but in general, according to Torqeedo their Travel 1003 with built-in battery will run for about 3 1/2 hours at half-throttle (3kts) or 35 minutes at full throttle (5kts) (or at 2kts it could run for over 10 hours). BTW, I was mistaken, their replacement battery costs $700, not $600. (The $600 battery is for the 503.)

I couldn't find any range figures on the Minn Kota site, but they do say that the maximum amp draw on the 55 lb thrust motor is 50 amps, so at full speed with a 100 amp-hour battery it theoretically would run for two hours. Considerably longer I'm sure at lesser speeds (interpolating from Torqeedo's figures, it should run 12 hours at half-throttle). All this assumes no other draws on the battery, which would be rare, but if you're running some LED lights and a small radio you won't be adding much load. I should also point out that trolling motors automatically shut down when they overheat, so if you use one for extended runs you may be stopping now and then to let the motor cool (and allow the solar panel to start bringing the battery back up). (I once capsized my Skerry and was pulled in by a guy with one of those big bass boats using a small trolling motor. I was hanging on to the boat while still in the water and was astounded by the power of that little motor. There was a hell of a lot of drag and he pulled it all in at a pretty good clip--I had to hold on tight.)

I'll be happy when I get the boat built and do some testing so I can report successes and/or problems to readers re the Minn Kota (or some other brand) trolling motor.

All that being said, I am not planning to run any races under motor power, or to drive around for extended periods. All I'm needing is some help getting out of difficult or dangerous situations near docks and that sort of thing, so I will most certainly not be using the motor much.

Question for Shudoman: I have read that the Torqeedo is pretty flimsy. Have you found that to be true?
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Re: Electric motor

Postby Shudoman on Fri May 22, 2015 11:55 am

Flimsy, no, not in the way that they use substandard materials.

However there is at least one aspect that isn't engineered very well. When you lock the motor in the up position (as when sailing to reduce drag), the pawl that holds it up engages the engine mount in such a way that it can easily bend and pop out of the pocket that it sets in. In my case it did this during the FL-120 during rough weather. This caused the motor to bob in and out of the water and move around during wave action. I had to bungie the engine in place to keep it from damaging the boat (it did cause a nice little gouge in the "transom skirt").

In addition it stripped out the little pocket in the engine mount which meant that even if I bent the pawl back into position it would then easily slip out and bend again. I'm going to have to buy a new pawl and a new mount and hope for better. I'm thinking that I will bungie it up whenever it's not in use. Not a major problem but one I shouldn't have to deal with on an engine that coast me $1800.00.

One thing that did work well for me is that I have an inverter attached to my house battery. At the end of every day I would plug the Torqueedo charger into the inverter and recharge it's battery.

I wish that I had gone with the LEHR. Live and learn.

Bill
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Re: Electric motor

Postby DanaDCole on Fri May 22, 2015 4:19 pm

Sorry to hear about all the problems, especially on such an expensive motor. I'm planning to stick with the trolling motor idea--if it doesn't work out it won't have cost me all that much. They come with either 36 or 42 inch shafts, so I think there will be some pretty good mounting options up high enough so that I can easily tilt it out of the water.

I think, though, if you are sailing on the ocean it might be better to have a propane or even gasoline engine. The propane is much cleaner burning though and there is no danger of spills. You might want to contact Charles Huie (Captain Charlie) and ask him about the Lehr now that he has had it for another year. When I met with him he was very happy with it.
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Re: Electric motor

Postby chaertl on Sun May 31, 2015 11:10 pm

Hi guys,

I've been running the LEHR for two years now and have a couple observations about it. The first is don't shift it into gear above idle when it's turned around for reverse. I had a pretty good wind coming straight onshore last summer and had it at about 1/8 throttle when I shifted. It jumped the lock that supposed to hold it down and broke the carry handle. Kind of expensive part at $45.00 but lesson learned. The second issue was the fuel line hardened up over this winter and since it was pulling on the regulator I replaced it so the metal line wouldn't crack on the regulator. If you don't use the oem line an aftermarket hose clamp won't fit through the hole in the front of the cylinder holder. This just causes the cylinder to sit a couple inches farther back so no big deal. When running it never needs to go over 1/4 throttle. You're at hull speed at that point and it just gets louder and wastes fuel any higher then that. At that setting I get about 2 1/2 to maybe 3 hours run time on a cylinder and can carry four extras in the front of the rope lockers. I started with restored Johnson outboards which worked fine but didn't hold enough fuel. After the second time running out I started carrying a 1 gallon gas can that was always under foot and not to easy to refuel on the water. When the family would go swimming off the boat they had climb through the oil slick around the back to get back onboard. I'm sold on the propane to say the least. Haven't had to give the kid a life jacket, tie a rope around her, and throw her overboard to swim us in since.

Chris
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Re: Electric motor

Postby captain charlie on Thu Jun 04, 2015 12:36 pm

Hi All, yes, I've been using the 2.5 HP LEHR propane motor for about two years and really have had NO problems with it. I recently purchased a 9 lb tank to use in place of the 1 lb canisters, and have been real pleased with it. I figure that extends the use time to about 35 to 40 15 minute ins and outs of the marina. The tank just fits in the aft part of the foot well. I would highly recommend the LEHR. It still costs $1050 with free freight from West Marine. captain charlie in arkansas
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Re: Electric motor

Postby Wayne G on Wed Aug 31, 2016 8:55 pm

Hi, I'm responding to this old post as I'm almost at the point of completing my PocketShip and am now looking for a suitable outboard (not necessarily electric). The 2.5 hp Lehr propane motor looks really attractive but I believe this only comes with a short shaft and wonder is the shaft long enough or if a transom modification is required? Any suggestions for an appropriate outboard would be great.

Wayne
Wayne Gray
Orlando Florida
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Re: Electric motor

Postby captain charlie on Tue Sep 06, 2016 9:44 pm

In regards to the Lehr 2.5 HP propane motor and its short shaft. I got a movable (up and down) motor mount from West Marine (their brand) and it works perfectly. When it is in the up position, the motor tilts to get it out of the water. I have it positioned so that when it is down, the tiller clears the shaft when it is in the locked forward position. I don't turn it around to reverse, as its more trouble to loosen the holding nut, swing it around, then tighten it again, all the while trying to not run into something. Hope this helps. As I've said before, I couldn't be more pleased with the motor itself. captain charlie, in little rock.
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