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Electric Motor for Spindrift 10s . .


Pete McCrary
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I understand the appeal of eschewing any form of engine. My first boat, a 16ft Wayfarer, never had an engine on it and I did a heck of a lot with that boat.

 

But not everybody has the same needs, or the same amount of free time, so we shouldn't judge other people on their choices. Our Spindrift will be a tender for a liveaboard boat, and will in effect be our car. Some people manage to live without a car, and walk or cycle everywhere- good for them. We don't personally want to live around those limitations. In particular I don't want to impose these on my other half, who will be just as likely to need to use the dinghy as I am.

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I dunno.  It’s a 10’ dinghy.  Since it’s a Spindrift, you know it’s a sweet rowing little gem.  Anything you slap on the transom is going to weigh as much as the boat.  I have hung my Suzuki 2.5 on the back of my Two Paw 8, but it seems unnatural.  The trolling motor makes more sense, but my Optima battery is stupid-heavy.  The oars are lighter, and make her go just fine.  I know the S10 would be a much sweeter row than this TP8, too.

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Ha, love it... and only $50. 

Quick/cheap solution for a bow thruster.  ?
 

Woah... some folks got “serious” on this. ?


Ok, one more... made for some hearty laughter... a weedwhacker upgrade. 

OR... WHAT DADS DO WHEN MOMS AREN’T AROUND!!

 

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During my recent test of my Torqeedo 1103 at the lake there was a significant amount of flotsam.  One piece struck the motor shaft, tilting the motor up and cavitating the prop and I think striking the prop before floating off.  I stopped the motor checked for damage and then continued on.  On closer examination at home I saw a line across one blade that I thought was a stress fracture. That made me start to wonder if a side mounted motor was at greater risk of striking floating debris than a transom mounted motor. Upon closer examination I noticed that the mark on the prop blade could be wiped away and that there was no obvious damage to the prop.  However I had already begun to revisit the idea of transom mounting the motor.

 

Skorpa is in need of a decent reboarding ladder and I am considering the possibility of a transom mounted combination motor mount/ folding boarding ladder.

Theoretically the Torqeedo will spend most of its time in the lazarette making the motor mount available to be used as a boarding ladder.   

 

The side mount makes installing the motor while underway easier because I have the lazarette blocking my access to the transom.

 

No I will not permanently mount the motor.  I absolutely refuse. Yes it is a little impractical but, I want to have the motor stored away while sailing.

 

 

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13 hours ago, Joe Anderson said:

 

 

No I will not permanently mount the motor.  I absolutely refuse. Yes it is a little impractical but, I want to have the motor stored away while sailing.

 

 

That's all there is to say about that.

 

I have no aft deck. I was thinking of some contraption that slides over mine to spread out the load and protect it.

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A friend side mounted his Torqeedo several years ago and discovered that position exposed it to significant spray that adversely affected the electronics.  Torqeedo was very accommodating and I believe it worked out but it is clear that a transom mount is better protected from both spray and debris.  I've dipped my rail in the water several times but have yet to dunk the transom.   

I've tried both side and transom mount with the EP Carry on the CS-17.  Performance seemed identical but I settled on the transom mount because it seemed more solid.  I don't take it on/off in the water but at 14 pounds motor weight installation is manageable . 

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7 hours ago, Randy Jones said:

  I've dipped my rail in the water several times but have yet to dunk the transom.   

Those of use who are considering or already use side mount do not intend to leave it mounted when we sail. A couple of us do not intend to mount it at all when there is wind.

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On 12/8/2020 at 9:57 PM, Randy Jones said:

   

I've tried both side and transom mount with the EP Carry on the CS-17.  

Randy,

I am interested in hearing about your experience with the EP carry. Their web site does not seem to carry a lot of info. From what I can gather the Torqeedo and the Epropulsion both have a similar design and about 3 times the battery capacity.  The Torqeedo gives you some data such as estimated range, speed, and power consumption. Some of that is not all that useful and the display can be difficult to read. It does beep at you when you reach 30% battery capacity and I think it may cut out at 20%.

 

The EP  Carry's light weight is definitely a plus in some situations. Does it give you any indication of state of charge. Do you know what kind of motor it has brushed or brushless?  Is the motor mounted vertically and does it directly drive the shaft?

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I finally had a chance to try out my EPropulsion Spirit1.0 plus today. Luanne and I spent about 2 hours tooling around in Rosebud (modified Spindrift 9). What a wonderfully odd sensation. Sailing, rowing or paddling give you a quiet way to move through the water. All of these means of propulsion require some effort, which I love. Stealthily moving through the water while doing nothing but looking around is not something I have done much until now. The motor works beautifully and is almost dead silent. The only sound you hear is the water against the hull. The LCD screen gives you a few bits of information. For me, the most helpful let’s you know your remaining battery time at any given speed. I forgot to bring my GPS to see how fast we were going. The range is quite impressive, however. Guessing that I was moving a normal rowing speed the range was almost 7 hours! Of course it drops considerably if your twist the throttle. So far, so good.

Ken

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Back in Michigan, there was a group of us who would occasiknally get together at a small lake club for a bass fishing tournament.  The club had a half dozen or so 10’ aluminum john boats.  We formed two-man teams.  One team member had to have a n electric trolling motor and a deep cycle battery.  (That would be me.). We would fish all morning, break for a mid-day weigh-in and lunch, and fish the afternoon. My rig never ran out of juice.  Pete, I’m telling you that you don’t need a Torquedo. A 35’ thrust Minkota for $100 will do nicely.

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I think a trolling motor is a legitimate alternative, to the more sophisticated electric motors. I don't have any experience with trolling motors but I did a little research and it seemed to me you had to pay considerably more than a hundred to get a reliable motor that was designed to operate in a salt water environment.  Anyway you can go really cheap or spend a $500 hundred or more for a trolling motor. You still need to source your battery if you go with a AGM battery you are talking about a significant amount of weight and some more cash. I am not saying which way is better, there are advantages and disadvantages.

 

I debated the two approaches lithium battery/brushless DC vs trolling motor/lead acid. This is what caused me to go with the former.

I have a software engineer neighbor he told me about a catamaran he built using two paddle boards a couple of lawn chairs with cup holders,  a cooler and a trolling motor with AGM battery. He used this craft for relaxing on the lake that adjoins his house  on summer evenings.

The next year he told me he was unhappy with the performance of the trolling motor and was upgrading to a Torqeedo (note there is no u).

He even offered to give me his trolling motor! Some how it no longer seemed right for my SKORPA to be equipped with a trolling motor. I know it is not rational but that is my story and I am sticking with it.

 

 

 

 

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I believe an AGM is a good choice over a traditional lead-acid battery.  If you capsize, the AGM won’t do as much environmental damage.  It does require a modern battery charger, though.  My old charger was worthless, when charging my new AGM’s.  What is required to charge a Lithium battery?  Why lithium?  Are they lighter per mAh?  Are there discharge limitations?  AGM’s don’t like to go below 11 volts; it is difficult for them to recover.  (That lesson cost me $130.)  I know the lipo batteries I use for R/C airplanes can be downright dangerous.  If the voltage goes below a certain point, they will spontaneously combust.  Make sure you get all the details, before you make your choice, Pete.  I do wish that you were closer.  I’d loan you my Minnkota and Optima.  I think you’d like it.

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On 12/24/2020 at 7:00 PM, Thrillsbe said:

I believe an AGM is a good choice over a traditional lead-acid battery.  If you capsize, the AGM won’t do as much environmental damage.  It does require a modern battery charger, though.  My old charger was worthless, when charging my new AGM’s.  What is required to charge a Lithium battery?  Why lithium?  Are they lighter per mAh?  Are there discharge limitations?  AGM’s don’t like to go below 11 volts; it is difficult for them to recover.  (That lesson cost me $130.)  I know the lipo batteries I use for R/C airplanes can be downright dangerous.  If the voltage goes below a certain point, they will spontaneously combust.  Make sure you get all the details, before you make your choice, Pete.  I do wish that you were closer.  I’d loan you my Minnkota and Optima.  I think you’d like it.

 

AGM are good batteries because they can be discharged deeper, and recharged faster, than traditional lead-acid types. But you pay for that extra performance.

'Lithium' covers a wide range of different chemistries. LiPo is very high energy density and is used in RC models and other high performance applications. But it's not considered safe enough for use on boats as they can go up in flames.

The preferred Lithium battery type for boats is LiFePO4, which can be considered no more hazardous than lead-acid. Compared to lead-acid they are much, much lighter per Ah, and they can be discharged to almost totally empty without damage, so in effect you only need half as many Ah. They also charge up quickly and efficiently, at a flat rate.

Discharge rates are generally around 1C which means for a 50A current, you need a 50Ah battery- but there are now some cells that can discharge at 3C, offering very high output from a tiny battery.

The big downside of LiFePO4 cells is that they must be treated very carefully. Even a momentary deviation from the safe voltage range will quickly destroy a cell. Not necessarily in a dangerous way, but it's expensive and inconvenient. If you just monitor the whole battery voltage (4 cells makes a 12v equivalent battery) you don't know whether an individual cell is too high or low, and sooner or later you will kill a cell as they go out of balance with each other. So you need a BMS, a little gizmo that watches each cell's voltage and activates some sort of cutoff when it gets too high or too low.The same gizmo will also redistribute power between the cells to keep them balanced.

 

It's a pretty big subject. Putting together a LiFePO4 battery on a DIY basis takes a bit of work- I'm still learning about it and haven't built one yet- but by sourcing the components directly you can make a very cost effective system. It would be ideal for powering a dinghy motor, but due to the complexity it doesn't really scale down well and makes more sense for big yacht or RV batteries.

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