A nice example of an electric aux at Benecia. This Nimble 24 has 12 AMG batteries that run an electric motor. It has a regen feature as well. Not a great performer under sail but you can always bump the throttle for a little boost. The owner says the control system was developed for the moon rover. All in all a nice boat. I leave him in the dust, tho under sail. Jon Barber Monty17 Ol'44 On Fri, Oct 16, 2020, 11:00 AM < montgomery_boats-request@mailman.xmission.com> wrote:
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Today's Topics:
1. Re: Electric motor range (was Re: changing Honda 2/2.3 prop) (casioqv@usermail.com) 2. Re: Electric motor range (was Re: changing Honda 2/2.3 prop) (Keith R. Martin) 3. Re: Electric motor range (was Re: changing Honda 2/2.3 prop) (John Schinnerer) 4. M17 motor mount (Jon Barber) 5. Re: Electric motor range (was Re: changing Honda 2/2.3 prop) (Alex Conley)
----------------------------------------------------------------------
Message: 1 Date: Thu, 15 Oct 2020 11:01:55 -0700 (PDT) From: casioqv@usermail.com To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Subject: Re: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop) Message-ID: <1288052005.76353782.1602784915158.JavaMail.zimbra@usermail.com> Content-Type: text/plain; charset=utf-8
Hi Dave,
I met a guy with a Newport 30 that he had converted to a fairly expensive electric drive system, and he claimed it did work for him for long cruises in the SF Bay area... he used a regen feature to charge the battery off the propeller while sailing. I don't think I would want something that slows the boat down like that, but he claimed that he would always end the day with a full battery on a multi-day cruise, and would never plug it in to recharge at the dock.
Compared to the Salish Sea, I think the Bay Area is quite different because you can reliably count on strong afternoon winds virtually everyday, so at worst you are motoring in the mornings and sailing in the evenings.
Sincerely, Tyler
----- Original Message ----- From: "scoobscobie" <scoobscobie@gmail.com> To: "john" <john@eco-living.net>, "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 10:40:56 AM Subject: Re: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop)
IMO electric remains usable for entry and exit of harbor. Even with smaller batteries with greater storage capacity (maybe one day having enough capacity for a day of motoring - full day of no wind is common on the Salish Sea, in addition to the current against you half the time +) the issue for a cruiser remains recharge - unless you stop at a marina that has 120v and you stay long enough to fully charge you are stuck. Solar on a 15' and 17' boat will be limited by deck space so full recharge is counted in days.
More ocean crossing sailors are converting to solar when their inboard diesel dies. These folks don't like to motor. These electric ocean crossers have solar but have simple low power draw electric systems as they cant run a generator/motor for four hours a day. So they use the electric motor getting out of harbor and have the crossing to recharge - multiple days or weeks of time.
There are also a small number of day sailors that convert to solar - but they don't cruise, just go out of harbor, sail, come back in. There are a few high-end 20-30' daysailors (that big and they call them daysailors!) that are being manufactured with electric. I also believe that ComPac has made a couple of custom order sub-20' electric onboard catboats.
I sold some Sage 17s with Torqeedos - in all cases boat was for daysailing and on a lake.
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Thu, Oct 15, 2020, 9:30 AM John Schinnerer via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
The specs for that trolling motor say minimum draw 9 amps, max draw 20 amps.
So with your little 11 amp-hour battery, you'll get maybe an hour at minimum draw, and half an hour or less at max draw. Some basic electrical math:
11 AH divided by 9 A = 1.2 H.
Please don't head out on a 5 hour tour (or even a "3 hour tour" :-) without other means to get back if the wind dies...at medium draw (15A) you'll get about 40 minutes of runtime at best.
You can get a 50AH or 60AH or more lithium battery, and it will be much lighter than same capacity lead-acid, but it will also lighten your wallet by a whole lot more.
cheers, John
On 10/15/20 9:09 AM, casioqv@usermail.com wrote:
I've been playing with using a 12V trolling motor on my M15 along with a cheap "Golf Cart Voltage Converter" to use a 48v electric bike battery pack with the trolling motor. It seems to work very well so far, but doesn't have quite the thrust of a gas outboard... good enough for exiting the marina, but not for motoring into a chop. The weight and runtime is comparable to a Torqueedo but at a tiny fraction of the cost. I've never ran it empty, but I suspect I can motor for 5-6 hours on the battery at about 3 knots.
Here's what I have: -DPLANET 30A 360W 12v Golf Cart 48V 36V to 12V Converter ($35 on Amazon) -Watersnake T24 ASP Saltwater trolling motor - designed for Kayaks ($150 on Amazon) -2017 Rad City Battery Pack 48V, 11.6 Ah (557 Wh) (from my eBike, but $399 new)
Total weight of this setup is 14.1 lbs with 7.4lbs for the battery, and 6.7lbs for the motor (converter is small and negligible). This is comparable to the lightest gas outboard I think has ever been sold- the 1.5hp Cruise'N'Carry at 12lbs. I used to have a Cruise'N'Carry, and found it to be cheaply made and extremely loud, so not really viable.
A big 24v 80lb thrust trolling motor would probably push the M15 at near hull speed and into a chop, but would be much much heavier than a comparable gas outboard, and requires dual large heavy batteries.
Sincerely, Tyler '81 M15 #157 S/V Defiant
----- Original Message ----- From: "Rimantas Aukstuolis" <raukstuolis1@gmail.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 8:18:41 AM Subject: Re: M_Boats: changing Honda 2/2.3 prop
What about those electric trolling motors? Hard to figure out thrust/power/torque comparisons. What little I know, comparing them to expensive Torquedo is that they use bulky 12 volt batteries vs lithium. Any thoughts? Rimas Aukstuolis
------------------------------
Message: 2 Date: Thu, 15 Oct 2020 11:03:32 -0700 From: "Keith R. Martin" <keith.richard.martin@gmail.com> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Subject: Re: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop) Message-ID: < CAOQkDsyNt6X-nn8L2wZiEtyTJW4sP3FqYrsDw8NVzugSt9tpQg@mail.gmail.com> Content-Type: text/plain; charset="UTF-8"
There are certainly electric/battery driven options for certain types of sailing with a M17/M15/Sage boats, particularly for day sailing on lakes etc. That said if you have a significant span of water to be traversed that is shared with larger craft (cargo & ferries etc..) one can get into really dicey situations if the wind dies... On one crossing of the Strait of Georgia this summer, I had that very circumstance, 7 NM out in the Strait heading for the gulf islands, the wind died to virtually nothing, and I had another 14 NM to go all the while dodging cargo vessels and ferries.. I can't imagine doing that without a gas powered engine....
Keith
*Keith R. Martin*
*Vancouver/Burnaby B.C.*
*Serenity M17, #353* *http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105 <http://www.msogphotosite.com/Scripts/Boats/boatsdetail.php?id=105>*
On Thu, 15 Oct 2020 at 10:41, Dave Scobie <scoobscobie@gmail.com> wrote:
IMO electric remains usable for entry and exit of harbor. Even with smaller batteries with greater storage capacity (maybe one day having enough capacity for a day of motoring - full day of no wind is common on the Salish Sea, in addition to the current against you half the time +) the issue for a cruiser remains recharge - unless you stop at a marina that has 120v and you stay long enough to fully charge you are stuck. Solar on a 15' and 17' boat will be limited by deck space so full recharge is counted in days.
More ocean crossing sailors are converting to solar when their inboard diesel dies. These folks don't like to motor. These electric ocean crossers have solar but have simple low power draw electric systems as they cant run a generator/motor for four hours a day. So they use the electric motor getting out of harbor and have the crossing to recharge - multiple days or weeks of time.
There are also a small number of day sailors that convert to solar - but they don't cruise, just go out of harbor, sail, come back in. There are a few high-end 20-30' daysailors (that big and they call them daysailors!) that are being manufactured with electric. I also believe that ComPac has made a couple of custom order sub-20' electric onboard catboats.
I sold some Sage 17s with Torqeedos - in all cases boat was for daysailing and on a lake.
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Thu, Oct 15, 2020, 9:30 AM John Schinnerer via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
The specs for that trolling motor say minimum draw 9 amps, max draw 20 amps.
So with your little 11 amp-hour battery, you'll get maybe an hour at minimum draw, and half an hour or less at max draw. Some basic electrical math:
11 AH divided by 9 A = 1.2 H.
Please don't head out on a 5 hour tour (or even a "3 hour tour" :-) without other means to get back if the wind dies...at medium draw (15A) you'll get about 40 minutes of runtime at best.
You can get a 50AH or 60AH or more lithium battery, and it will be much lighter than same capacity lead-acid, but it will also lighten your wallet by a whole lot more.
cheers, John
On 10/15/20 9:09 AM, casioqv@usermail.com wrote:
I've been playing with using a 12V trolling motor on my M15 along with a cheap "Golf Cart Voltage Converter" to use a 48v electric bike battery pack with the trolling motor. It seems to work very well so far, but doesn't have quite the thrust of a gas outboard... good enough for exiting the marina, but not for motoring into a chop. The weight and runtime is comparable to a Torqueedo but at a tiny fraction of the cost. I've never ran it empty, but I suspect I can motor for 5-6 hours on the battery at about 3 knots.
Here's what I have: -DPLANET 30A 360W 12v Golf Cart 48V 36V to 12V Converter ($35 on Amazon) -Watersnake T24 ASP Saltwater trolling motor - designed for Kayaks ($150 on Amazon) -2017 Rad City Battery Pack 48V, 11.6 Ah (557 Wh) (from my eBike, but $399 new)
Total weight of this setup is 14.1 lbs with 7.4lbs for the battery, and 6.7lbs for the motor (converter is small and negligible). This is comparable to the lightest gas outboard I think has ever been sold- the 1.5hp Cruise'N'Carry at 12lbs. I used to have a Cruise'N'Carry, and found it to be cheaply made and extremely loud, so not really viable.
A big 24v 80lb thrust trolling motor would probably push the M15 at near hull speed and into a chop, but would be much much heavier than a comparable gas outboard, and requires dual large heavy batteries.
Sincerely, Tyler '81 M15 #157 S/V Defiant
----- Original Message ----- From: "Rimantas Aukstuolis" <raukstuolis1@gmail.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 8:18:41 AM Subject: Re: M_Boats: changing Honda 2/2.3 prop
What about those electric trolling motors? Hard to figure out thrust/power/torque comparisons. What little I know, comparing them to expensive Torquedo is that they use bulky 12 volt batteries vs lithium. Any thoughts? Rimas Aukstuolis
------------------------------
Message: 3 Date: Thu, 15 Oct 2020 12:27:31 -0700 From: John Schinnerer <john@eco-living.net> To: For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Subject: Re: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop) Message-ID: <3e32bbdc-f402-c90e-e75a-df81367da72b@eco-living.net> Content-Type: text/plain; charset=utf-8; format=flowed
Ah, missed the battery voltage, thought it was 12v. Do it all in watts then...
48v x 11AH = 528WH
Say moderate speed draws 12A, then 12A x 12.6V = 144W
528WH/144W = ~3.6H, at 12A draw, as you say.
There is also some loss of efficiency in all battery powered systems, typically at least 10% and usually more like 20%, so take 20% off the theoretical math to get a safer real world estimate.
Part of the efficiency loss with battery storage is in the recharging, which isn't an issue in this situation, so 10% loss might be realistic here.
Not bad then for what you put into it!
cheers, John
On 10/15/20 10:38 AM, casioqv@usermail.com wrote:
Hi John,
The motor draws 9-20 amps only max startup (stall/0 knots) at 12v on the low and high speeds respectively. This 11 aH battery is a powerful 48v battery for electric bicycles, so you have to multiply the amperage by 4x to compare with a 12v lead acid. The stepdown converter gives 1/4 the voltage and 4x the aH as output.
I estimate on high speed once cruising it draws about 13amps at 12v, so that would be approx (11.6*4)/13=3.57 hours of runtime. Let's say it draws only 6 amps at cruise on low speed, that would be approx (11.6*4)/6=7.73 hours of runtime.
Indeed, I did motor with it on low speed for over an hour, and the battery was still reading 100% on the built in meter it has (which only reads in 20% intervals), so it was definitely over 80% at the end.
Sincerely, Tyler
----- Original Message ----- From: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 9:29:42 AM Subject: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop)
The specs for that trolling motor say minimum draw 9 amps, max draw 20 amps.
So with your little 11 amp-hour battery, you'll get maybe an hour at minimum draw, and half an hour or less at max draw. Some basic electrical math:
11 AH divided by 9 A = 1.2 H.
Please don't head out on a 5 hour tour (or even a "3 hour tour" :-) without other means to get back if the wind dies...at medium draw (15A) you'll get about 40 minutes of runtime at best.
You can get a 50AH or 60AH or more lithium battery, and it will be much lighter than same capacity lead-acid, but it will also lighten your wallet by a whole lot more.
cheers, John
On 10/15/20 9:09 AM, casioqv@usermail.com wrote:
I've been playing with using a 12V trolling motor on my M15 along with a cheap "Golf Cart Voltage Converter" to use a 48v electric bike battery pack with the trolling motor. It seems to work very well so far, but doesn't have quite the thrust of a gas outboard... good enough for exiting the marina, but not for motoring into a chop. The weight and runtime is comparable to a Torqueedo but at a tiny fraction of the cost. I've never ran it empty, but I suspect I can motor for 5-6 hours on the battery at about 3 knots.
Here's what I have: -DPLANET 30A 360W 12v Golf Cart 48V 36V to 12V Converter ($35 on Amazon) -Watersnake T24 ASP Saltwater trolling motor - designed for Kayaks ($150 on Amazon) -2017 Rad City Battery Pack 48V, 11.6 Ah (557 Wh) (from my eBike, but $399 new)
Total weight of this setup is 14.1 lbs with 7.4lbs for the battery, and 6.7lbs for the motor (converter is small and negligible). This is comparable to the lightest gas outboard I think has ever been sold- the 1.5hp Cruise'N'Carry at 12lbs. I used to have a Cruise'N'Carry, and found it to be cheaply made and extremely loud, so not really viable.
A big 24v 80lb thrust trolling motor would probably push the M15 at near hull speed and into a chop, but would be much much heavier than a comparable gas outboard, and requires dual large heavy batteries.
Sincerely, Tyler '81 M15 #157 S/V Defiant
----- Original Message ----- From: "Rimantas Aukstuolis" <raukstuolis1@gmail.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 8:18:41 AM Subject: Re: M_Boats: changing Honda 2/2.3 prop
What about those electric trolling motors? Hard to figure out thrust/power/torque comparisons. What little I know, comparing them to expensive Torquedo is that they use bulky 12 volt batteries vs lithium. Any thoughts? Rimas Aukstuolis
On Thu, Oct 15, 2020 at 11:14 AM Alex Conley <conley.alex@gmail.com> wrote:
Thanks for the caution re overpropping. I guess the real solution would be to change the gear ratio to turn a larger prop slower at a given throttle setting. Then you could use more of the engines range and gain both torque at higher speeds and a slower low speed- both on my wishlist. But not a mod I can see making- it?d be a whole new lower end... It seems most of the little outboards we use on our displacement sailboats are geared to get a little inflatable zipping around; have there been attempts to make an outboard geared for small sailboats, or is it just too niche a market? I?ll plan to live with my imperfect 35 yr old motor long enough to hopefully hit the point where the range/cost ratio of the electrics makes them a good replacement....
On Wed, Oct 14, 2020 at 8:10 AM Dave Scobie <scoobscobie@gmail.com> wrote:
Alex:
Somewhere a few years ago I read about a person changing out the prop on the small Honda - wasn't a Mboat. I can't remember any specifics.
The general consensus was the problem is the motor will likely be overstressed under the load - especially a concern with the powerhead being or cooled.
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Wed, Oct 14, 2020, 8:03 AM Alex Conley <conley.alex@gmail.com> wrote:
Ive also searched for a high thrust prop for my 35 yr old Honda 2 hp but never seen one. In these days of 3D printers/milling, strong plastics and computer designs, it would seem there might be an opportunity for someone to work up some designs that could then be made on order.
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
------------------------------
Message: 4 Date: Thu, 15 Oct 2020 13:11:23 -0700 From: Jon Barber <brbrbarber@gmail.com> To: montgomery_boats@mailman.xmission.com Subject: M_Boats: M17 motor mount Message-ID: < CAFwAWQuee-vW4-_VOof5Uo3K2ZpCNj5MtB080x4U-j-T2t32Cg@mail.gmail.com> Content-Type: text/plain; charset="UTF-8"
As I recall, Gary Oberbeck had made a sweet motor mount from mast section welded to aluminum plates. All very elegant. I can't send photos, either.
My 2 hp Honda in the notch is perfect. I wouldn't consider any other setup.
Jon Barber Monty17 Ol'44
------------------------------
Message: 5 Date: Thu, 15 Oct 2020 16:41:17 -0700 From: Alex Conley <conley.alex@gmail.com> To: John Schinnerer <john@eco-living.net>, For and about Montgomery Sailboats <montgomery_boats@mailman.xmission.com> Subject: Re: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop) Message-ID: < CACj3+t+9vzkj-4MYKBYhAwUyn1-ad4_VSiEcOfnfHzhdxf2qvw@mail.gmail.com> Content-Type: text/plain; charset="UTF-8"
Thanks all- love learning from the chat here. My brief experiments with a 36lb thrust trolling motor (a little bigger thanTyler's 24 lb thrust Watersnake) on My M15 made me conclude that while it was great for an hour or two of fishing on a still lake while waiting for the wind, when the wind came up to even 10 knots, it failed to have the power to maintain decent way and steerage (in comparison, in its toughest test, my little 2 horse honda let me tow a stranded ski boat with 5 people in it off a rough lee shore in a 20-25 knot breeze with only a little whining in the worst of the waves). A standard trolling motor setup up to the task is a heavy proposition (though in a boat designed for it, it can be impressive- look up Thomas Hruby and his St Pierre Dory Daddy's Third) - and part of what I love about my M15 is how light and responsive she is. Tyler's 48v battery idea- with multiple batteries and a more powerful trolling motor might work, but weight and price will climb quickly (see if I can find the time to and brainspace to calc out what that might look like). The Torquedos and like are really coming along- I think they'd handle all the boat needs except for the range limitation, but until the range comes along, the cost is a barrier. So right now I concur w Dave that the current electrics are largely limited to protected daysailing and not a good match for Keith's gulf island crossing and most other open water work- however, I suspect ultimately we'll see the cost of a Torquedo style motor drop a bit and come with an option for portable generator/fuel cell to act as a range extender for times when range is essential (as so many daysail most of the time, and have only a few extended outings in a year). So for now I'll keep that 1985 2 horse going, and see what's on the market in a few years...
On Thu, Oct 15, 2020 at 12:28 PM John Schinnerer via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
Ah, missed the battery voltage, thought it was 12v. Do it all in watts then...
48v x 11AH = 528WH
Say moderate speed draws 12A, then 12A x 12.6V = 144W
528WH/144W = ~3.6H, at 12A draw, as you say.
There is also some loss of efficiency in all battery powered systems, typically at least 10% and usually more like 20%, so take 20% off the theoretical math to get a safer real world estimate.
Part of the efficiency loss with battery storage is in the recharging, which isn't an issue in this situation, so 10% loss might be realistic here.
Not bad then for what you put into it!
cheers, John
On 10/15/20 10:38 AM, casioqv@usermail.com wrote:
Hi John,
The motor draws 9-20 amps only max startup (stall/0 knots) at 12v on the low and high speeds respectively. This 11 aH battery is a powerful 48v battery for electric bicycles, so you have to multiply the amperage by 4x to compare with a 12v lead acid. The stepdown converter gives 1/4 the voltage and 4x the aH as output.
I estimate on high speed once cruising it draws about 13amps at 12v, so that would be approx (11.6*4)/13=3.57 hours of runtime. Let's say it draws only 6 amps at cruise on low speed, that would be approx (11.6*4)/6=7.73 hours of runtime.
Indeed, I did motor with it on low speed for over an hour, and the battery was still reading 100% on the built in meter it has (which only reads in 20% intervals), so it was definitely over 80% at the end.
Sincerely, Tyler
----- Original Message ----- From: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 9:29:42 AM Subject: M_Boats: Electric motor range (was Re: changing Honda 2/2.3 prop)
The specs for that trolling motor say minimum draw 9 amps, max draw 20 amps.
So with your little 11 amp-hour battery, you'll get maybe an hour at minimum draw, and half an hour or less at max draw. Some basic electrical math:
11 AH divided by 9 A = 1.2 H.
Please don't head out on a 5 hour tour (or even a "3 hour tour" :-) without other means to get back if the wind dies...at medium draw (15A) you'll get about 40 minutes of runtime at best.
You can get a 50AH or 60AH or more lithium battery, and it will be much lighter than same capacity lead-acid, but it will also lighten your wallet by a whole lot more.
cheers, John
On 10/15/20 9:09 AM, casioqv@usermail.com wrote:
I've been playing with using a 12V trolling motor on my M15 along with a cheap "Golf Cart Voltage Converter" to use a 48v electric bike battery pack with the trolling motor. It seems to work very well so far, but doesn't have quite the thrust of a gas outboard... good enough for exiting the marina, but not for motoring into a chop. The weight and runtime is comparable to a Torqueedo but at a tiny fraction of the cost. I've never ran it empty, but I suspect I can motor for 5-6 hours on the battery at about 3 knots.
Here's what I have: -DPLANET 30A 360W 12v Golf Cart 48V 36V to 12V Converter ($35 on Amazon) -Watersnake T24 ASP Saltwater trolling motor - designed for Kayaks ($150 on Amazon) -2017 Rad City Battery Pack 48V, 11.6 Ah (557 Wh) (from my eBike, but $399 new)
Total weight of this setup is 14.1 lbs with 7.4lbs for the battery, and 6.7lbs for the motor (converter is small and negligible). This is comparable to the lightest gas outboard I think has ever been sold- the 1.5hp Cruise'N'Carry at 12lbs. I used to have a Cruise'N'Carry, and found it to be cheaply made and extremely loud, so not really viable.
A big 24v 80lb thrust trolling motor would probably push the M15 at near hull speed and into a chop, but would be much much heavier than a comparable gas outboard, and requires dual large heavy batteries.
Sincerely, Tyler '81 M15 #157 S/V Defiant
----- Original Message ----- From: "Rimantas Aukstuolis" <raukstuolis1@gmail.com> To: "For and about Montgomery Sailboats" < montgomery_boats@mailman.xmission.com> Sent: Thursday, October 15, 2020 8:18:41 AM Subject: Re: M_Boats: changing Honda 2/2.3 prop
What about those electric trolling motors? Hard to figure out thrust/power/torque comparisons. What little I know, comparing them to expensive Torquedo is that they use bulky 12 volt batteries vs lithium. Any thoughts? Rimas Aukstuolis
On Thu, Oct 15, 2020 at 11:14 AM Alex Conley <conley.alex@gmail.com> wrote:
Thanks for the caution re overpropping. I guess the real solution would be to change the gear ratio to turn a larger prop slower at a given throttle setting. Then you could use more of the engines range and gain both torque at higher speeds and a slower low speed- both on my wishlist. But not a mod I can see making- it?d be a whole new lower end... It seems most of the little outboards we use on our displacement sailboats are geared to get a little inflatable zipping around; have there been attempts to make an outboard geared for small sailboats, or is it just too niche a market? I?ll plan to live with my imperfect 35 yr old motor long enough to hopefully hit the point where the range/cost ratio of the electrics makes them a good replacement....
On Wed, Oct 14, 2020 at 8:10 AM Dave Scobie <scoobscobie@gmail.com> wrote:
Alex:
Somewhere a few years ago I read about a person changing out the prop on the small Honda - wasn't a Mboat. I can't remember any specifics.
The general consensus was the problem is the motor will likely be overstressed under the load - especially a concern with the powerhead being or cooled.
:: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/
On Wed, Oct 14, 2020, 8:03 AM Alex Conley <conley.alex@gmail.com> wrote:
> Ive also searched for a high thrust prop for my 35 yr old Honda 2 hp but > never seen one. In these days of 3D printers/milling, strong plastics and > computer designs, it would seem there might be an opportunity for someone > to work up some designs that could then be made on order. >
-- John Schinnerer - M.A., Whole Systems Design -------------------------------------------- - Eco-Living - Whole Systems Design Services People - Place - Learning - Integration john@eco-living.net - 510.982.1334 http://eco-living.net http://sociocracyconsulting.com
------------------------------
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